WO2023053870A1

WO2023053870A1 - Fan blade, engine, and structure with anti-icing and de-icing functions

Info

Publication number: WO2023053870A1
Application number: PCT/JP2022/033524
Authority: WO
Inventors: 拓哉水野; 和夫谷; 正弘北條; 正也鈴木
Original assignee: 国立研究開発法人宇宙航空研究開発機構
Priority date: 2021-10-01
Filing date: 2022-09-07
Publication date: 2023-04-06
Also published as: JPWO2023053870A1

Abstract

[Problem] To provide a fan blade, an engine, and a structure with anti-icing and de-icing functions, having a simple structure and capable of efficiently carrying out anti-icing and de-icing. [Solution] Provided is a fan blade arranged on an intake port side of an engine and comprising: a fan blade body which is formed of carbon fiber reinforced plastic; and a pair of a first current supply portion and a second current supply portion which cause a current to flow through carbon fibers contained in the carbon fiber reinforced plastic to cause the current to flow through a current supply area of the fan blade body. The heat generation amount of the current supply area on a first side of the fan blade body is larger than the heat generation amount of the current supply area on a second side of the fan blade body when the current is caused to flow between the pair of the first current supply portion and the second current supply portion.

Description

Fan blades, engines and structures with anti-icing and de-icing functions

The present invention relates to fan blades, engines, and structures with anti-icing/de-icing functions used in aircraft, for example.

In recent years, fan blades have become larger and have improved fuel efficiency, and development has progressed to strengthen impact resistance and flutter resistance when foreign objects enter. However, at the same time, it had another fundamental problem of making the engine itself heavier due to the increased weight of the fan blades. Furthermore, fan blades are characterized by the occurrence of icing phenomena corresponding to the number of blades when the aircraft flies at high altitudes in a low-temperature environment. This icing phenomenon is a complex natural phenomenon that has multiple aspects of fluid and heat, but it reduces the performance of jet engines during flight, and in the worst case, surges and shedding ( This is an important problem that must be solved as soon as possible because it involves the risk of mechanical damage to the inside of the jet engine due to the phenomenon in which ice that has grown due to icing is released.

In order to solve the former problem of fuel efficiency improvement and weight increase, fan blades are made of carbon fiber reinforced composite materials that have high specific strength and specific modulus, excellent mechanical properties, and high functional properties such as weather resistance. The use of plastic (Carbon Fiber Reinforced Plastic: CFRP) is spreading.

In the 1960s, the development of carbon fiber reinforced plastic composite materials using resin as a base material began, mainly for military aircraft. In aircraft, it replaces conventional metal materials and is being put to practical use as a new aircraft application. It should be noted that the current composite material properties are more than 2.5 times the strength and elastic modulus of steel, and the specific gravity is less than 1/4, which is expected to enhance mechanical properties and reduce weight. showing. In fact, the trend in recent years is for large aircraft, the Airbus A350 and the Boeing 787, to deploy composite materials over 50% of the airframe weight.

In response to the latter issue related to icing, the airframe and engine are equipped with anti-icing and de-icing systems. The following techniques have been disclosed as such systems.

Non-Patent Document 1 discloses a technique that utilizes high-temperature air (bleed air) bled from the compressor of the engine.

Non-Patent Document 2 discloses a technique using an electric heater to which a heating wire or the like is attached.

Non-Patent Document 3 discloses a technology that utilizes shape change by blowing air into the anti-icing boots (rubber membrane) provided on the leading edge of the main wing and tail wing.

Patent Documents

1 and 2 disclose techniques that apply a coating in advance to areas that are prone to icing, baking, or utilizing nano-sized structure pin processing.

Patent Document 3 discloses a technique that utilizes mechanical vibration of an actuator or the like.

JP 2012-26361 A WO2008/087861 U.S. Patent Application Publication No. 2013/032671 JP 2019-108818 A

Regarding the technology that utilizes bleed air, when the engine output is low, the anti-icing function declines, causing variations in effectiveness.

As for the electric heater, it is difficult to set and process the thin member of the fan, and it also has an aerodynamic effect.

As for the anti-icing boots, it is necessary to install a complex mechanical structure inside the wing because it uses the air extracted from the engine's compressor to operate, and the anti-icing boots need to be replaced in a short period of 2 to 3 years. is required.

Regarding anti-icing coatings and nano-sized structure pins, there is instability and lack of durability due to aging.

　Regarding mechanical vibrations such as actuators, the complex structure makes maintenance difficult and increases the weight.

The conventional technology described above is a countermeasure technology that specializes in the problem of icing, and is a technology that realizes functions from the configuration and structure that are added (added) to conventional aircraft specifications later. It is obvious that the volume and weight will increase compared to the basic specifications, the configuration and structure will become more complicated, and processing and maintenance will become more difficult, and other effects will occur.

In view of the circumstances as described above, it is an object of the present invention to provide a fan blade, an engine, and a structure with anti-icing and de-icing functions that are simple in structure and capable of efficiently performing anti-icing and de-icing. That's what it is.

A fan blade according to one aspect of the present invention includes:
A fan blade arranged on the intake side of an engine,
a fan blade body made of carbon fiber reinforced plastic;
a pair of first current-carrying parts and second current-carrying parts for causing current to flow through the current-carrying region of the fan blade main body by causing current to flow through carbon fibers contained in the carbon fiber reinforced plastic;
and
When a current is passed between the pair of the first current-carrying portion and the second current-carrying portion, the amount of heat generated in the current-carrying region of the fan blade body on the first side of the fan blade body is the second level of the fan blade body. higher than the calorific value of the current-carrying region on the side.

In the fan blade according to one aspect of the present invention, the carbon fiber of carbon fiber reinforced plastic (CFRP) is conductive, and the resin material such as epoxy as the matrix material is insulating, so that the current flows. It utilizes the property of generating heat. That is, a pair of first current-carrying part and second current-carrying part are provided on the first side and the second side of the fan blade body made of CFRP for passing current to the current-carrying region of the fan blade body, and a voltage is generated between them. is applied to flow a current, the fan blade body itself generates heat due to its resistance, and performs anti-icing and de-icing. Therefore, anti-icing and de-icing can be performed with a simple structure. Airplane jet engine fan blades tend to have a large amount of icing on the leading edge side (first side) and almost no icing on the trailing edge side (second side) because supercooled droplets in the air do not collide. There is Therefore, by making the amount of heat generated on the first side of the fan blade body higher than the amount of heat generated on the second side, the first side can be more efficiently deiced.

The calorific value of the energized region on the first side of the fan blade body is higher than the calorific value of the energized region on the second side,
The conductive fiber density on the first side, which is the ratio of the carbon fibers conductively connected to the first conductive portion to the length of the first conductive portion in the span direction, is the length of the second conductive portion in the span direction. higher than the conductive fiber density on the second side, which is the ratio of the carbon fibers conductively connected to the second current-carrying portion to the thickness.

The fan blade body includes a plurality of laminated layers, and the carbon fibers contained in the plurality of layers have different orientations,
By connecting one or more layers selected from the plurality of layers to the first conductive portion and the second conductive portion, the conductive fiber density on the first side is higher than the conductive fiber density on the second side. It can be expensive.

The orientation of carbon fibers varies depending on the required specifications and characteristics. By selecting one or more layers with different carbon fiber orientations and connecting them to the first current-carrying portion and the second current-carrying portion, it is possible to achieve a difference in conductive fiber density.

The one or more layers connected to the first current-carrying part and the second current-carrying part,
a first layer comprising carbon fibers oriented in a first direction positively inclined with respect to both the span direction and the cord direction; and/or negatively inclined with respect to both the span direction and the cord direction. A second layer comprising carbon fibers oriented in a second direction may also be included.

By selecting one or more layers with different orientations of carbon fibers and connecting them to the first current-carrying part and the second current-carrying part, it is possible to achieve a difference in conductive fiber density.

The length of the second conducting portion in the span direction may be longer than the length of the first conducting portion in the span direction.

Focusing on the carbon fibers conducting to both the first conducting portion and the second conducting portion (that is, the carbon fibers contained in the conducting region), the number of carbon fibers conducting to the first conducting portion and the second It is the same as the number of carbon fibers conducting to the current-carrying part. Therefore, when the same number of carbon fibers are electrically connected to the short first current-carrying portion and the long second current-carrying portion, the length (short) in the span direction of the first current-carrying portion is electrically connected to the first current-carrying portion. The conductive fiber density on the first side, which is the ratio of the carbon fibers that are connected to the second side, is the ratio of the carbon fibers that are conducted to the second current-carrying portion with respect to the length (long) of the second current-carrying portion in the span direction. higher than the conducting fiber density of The conductive fiber density on the first side is higher than the conductive fiber density on the second side, so that the amount of heat generated on the first side of the fan blade body is higher than that on the second side. The same number of carbon fibers conducting on the first side exist in a narrower area than on the second side. Therefore, the temperature of the first side becomes higher than that of the second side due to the heat generated by the carbon fibers themselves.

The fan blade body includes a plurality of laminated layers,
a layer on the pressure side selected from the plurality of layers is connected to the first conducting portion and the second conducting portion;
When a current is passed between the pair of first current-carrying parts and the second current-carrying part, the amount of heat generated on the pressure side of the fan blade body may be higher than the amount of heat generated on the suction side of the fan blade body. .

When icing on the fan blades of an aircraft jet engine, most of the ice adheres and concentrates on the pressure surfaces of the fan blades. Therefore, it is desirable to actively heat the positive pressure surface on which a large amount of ice is deposited. As described above, voltage is applied to the fan blade body between the first current-carrying part and the second current-carrying part, so that current flows, and the fan blade body itself generates heat due to its resistance. Therefore, by making the amount of heat generated on the pressure side of the fan blade body higher than the amount of heat generated on the suction side of the fan blade body, the pressure side can be more efficiently deiced. By selecting and energizing the layer close to the pressure side, it is possible to secure the heat generation area and heat generation temperature with the minimum applied power, and also to set the heat generation temperature on the pressure side and the suction side of the fan blade. Specifically, the temperature of the pressure surface on which a large amount of ice adheres can be raised to a high temperature, and the temperature of the suction surface on which a small amount of ice adheres can be lowered. With this configuration, it is possible to advantageously function in the hollow structure that accompanies the recent weight reduction of fan blades.

a first side conductive adhesive and a second side conductive adhesive that connect the fan blade body to the first conductive portion and the second conductive portion;
The calorific value of the energized region on the first side of the fan blade body is higher than the calorific value of the energized region on the second side,
The resistance value of the first side conductive adhesive may be higher than the resistance value of the second side conductive adhesive.

The conductive adhesive is used to form a current path through selected carbon fibers, but the resistance component of the conductive adhesive is mainly in the area passing through the point where ice buildup concentrates on the fan blade. By selecting the ratio, heat generation effect and anti-icing effect can be obtained predominantly.

The fan blade body includes a plurality of laminated layers,
The first side conductive adhesive and the second side conductive adhesive may connect one or more layers selected from the plurality of layers to the first conductive portion and the second conductive portion. good.

By bonding the electrode and the fan blade body with a conductive adhesive, the adhesiveness and contact area with the carbon fiber increase, so local temperature rise and poor conduction at the attachment point between the electrode and the fan blade body can be prevented and power consumption can be reduced. Thereby, an effective temperature rise can be obtained even at a low voltage.

The resistance value of the first side conductive adhesive on the pressure side of the fan blade body is higher than the resistance value of the first side conductive adhesive on the suction side of the fan blade body,
A resistance value of the second side conductive adhesive on the pressure side may be lower than a resistance value of the second side conductive adhesive on the suction side.

In addition to the leading edge and hub of an aircraft jet engine, ice builds up on the pressure surface of the fan blade. Therefore, it is desirable to actively heat the positive pressure surface on which a large amount of ice is deposited. As described above, voltage is applied to the fan blade body between the first current-carrying part and the second current-carrying part, so that current flows, and the fan blade body itself generates heat due to its resistance. Therefore, by changing the method of applying the conductive adhesive, more current can flow through the layer closer to the pressure surface, and conversely, less current can flow through the layer closer to the suction surface. As a result, the amount of heat generated on the pressure side can be increased, and the first side can be more efficiently deiced.

the first side is a leading edge side of the fan blade body;
The second side may be the trailing edge side of the fan blade body.

Airplane jet engine fan blades tend to have a large amount of icing on the leading edge side (first side) and almost no icing on the trailing edge side (second side) because supercooled droplets in the air do not collide. There is Therefore, by making the amount of heat generated on the first side of the fan blade body higher than the amount of heat generated on the second side, the first side can be more efficiently deiced.

An engine according to one aspect of the present invention includes:
a rotating shaft;
a fan disk provided on the inlet side of the rotating shaft;
a fan blade according to one aspect of the present invention, which is detachably attached to the fan disk;
A first current-carrying part and a second current-carrying part are provided on the fan disk side and the fan blade side, respectively, and when the fan blade is attached to the fan disk, they are electrically connected to each other on the fan disk side. a pair of connection terminals for energizing the power source and the first current-carrying part and the second current-carrying part;
Equipped with

A structure with anti-icing and de-icing functions according to one aspect of the present invention includes:
a plate-shaped member made of carbon fiber reinforced plastic and having an icing area due to gas flow;
Provided on the first side and the second side of the plate-shaped member so as to include the icing region, current is passed through the carbon fiber contained in the carbon fiber reinforced plastic, and the current is passed through the current-carrying region of the plate-shaped member. A pair of first current-carrying part and second current-carrying part for flowing the
and
An amount of heat generated in the energized area on the first side of the plate member is higher than that of the energized area on the second side.

According to the present invention, anti-icing and de-icing can be performed efficiently with a simple structure.

Note that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

1 is a schematic diagram showing the configuration of a jet engine according to one embodiment of the present invention; FIG. FIG. 2 is a side view showing the basic configuration of a single fan blade shown in FIG. 1; 1 is a schematic diagram showing the configuration of a fan blade according to one embodiment of the present invention; FIG. FIG. 4 shows a modification of the fan blade shown in FIG. 3; FIG. It is a graph which shows a test result. FIG. 4 is a perspective view showing a state in which fan blades are attached to the fan disk; FIG. 2 is a diagram for explaining the configuration of wiring for supplying power to fan blades according to an embodiment of the present invention; FIG. 4 is a diagram for explaining a configuration of power supply to fan blades according to an embodiment of the present invention; FIG. 4 is a diagram for explaining another configuration of power supply to fan blades according to an embodiment of the present invention; FIG. 4 is an exploded view schematically showing laminated prepregs forming a fan blade body; 1 schematically shows a lamination cross-section of a laminated prepreg specimen used in an experiment. 1 shows a laminated prepreg specimen used in an experiment. It is a schematic diagram for explaining the conductive fiber density used in the experiment. Type 1 and type 2 specimens used in the experiment are shown. An experimental icing wind tunnel setup is shown. It is a photograph which shows an anti-icing test result. It is a photograph which shows an anti-icing test result. It is a graph which shows an anti-icing test result. It is a graph which shows an anti-icing test result. It is thermography which shows a windless heat generation test result. It is a graph which shows a windless heat generation test result. Another specimen used in the experiment is schematically shown. It is thermography which shows a test result. It is a graph which shows a test result. It is a photograph showing a test result. It is a photograph showing a test result. It is a photograph showing a test result. It is a photograph showing a test result. It is a graph which shows a test result. It is a graph which shows a test result. It is thermography which shows a test result. A specific example of layer selection used in the experiment is shown. It is a thermography which shows the layer selective draft temperature confirmation test result. It is a graph which shows a layer selective draft temperature confirmation test result. It is a graph which shows a layer selective draft temperature confirmation test result. It is a photograph showing a test result. It is a photograph showing a test result. It is a graph which shows a test result. It is a graph which shows a test result. It is a graph which shows a test result. It is a graph which shows a test result.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

　I. overview

1. Jet engine configuration

FIG. 1 is a schematic diagram showing the configuration of a jet engine according to one embodiment of the present invention.

A jet engine 1 has a low-pressure shaft 2 and a high-pressure shaft 3 as rotating shafts arranged at the center.
A spinner 5, a fan disk 6, a low-pressure compressor 9, and a low-pressure turbine 15 are attached to the low-pressure shaft 2 from the intake port 4 side. ing.

Downstream of the fan blades 8, a low-pressure compressor 9, a high-pressure compressor 11, a combustor 13, a high-pressure turbine 14, a low-pressure turbine 15, a strut 16, and a core nozzle 17 are arranged. A fan outlet guide vane 10 and a bypass nozzle 12 are arranged in another flow path.
A high pressure compressor 11 and a high pressure turbine 14 are attached to the high pressure shaft 3 .

In the jet engine 1 configured in this way, icing occurs due to supercooled water droplets on the spinner 5 and the fan blades 8 near the intake port 4 . Such icing poses problems of deterioration of aerodynamic performance due to shape change and mechanical damage due to peeling ice blocks. The fan blade 8 shown below solves this problem.

2. Configuration of fan blades (overview)

FIG. 2 is a side view showing the basic configuration of the single fan blade shown in FIG. FIG. 3 is a schematic diagram showing the configuration of a fan blade according to one embodiment of the present invention.

The fan blades 8 are arranged on the intake port 4 side of the engine. The fan blade 8 includes a fan blade main body 21, a sheath 22 arranged on the front edge 24 side (first side) of the fan blade main body 21, and a rear edge 25 side (second side) of the fan blade main body 21. and a guard 23.

The fan blade main body 21 is made of carbon fiber reinforced plastic (CFRP, hereinafter referred to as "CFRP"), and is typically a plate-shaped molding. CFRP is constructed by laminating prepregs made of, for example, carbon fibers as reinforcing fibers and epoxy resin as a matrix, with the orientation of the carbon fibers being quasi-isotropic.

The sheath 22 is made of a rigid conductive metal, and covers the front edge 24 side of the fan blade body 21 from the hub side 26 as the base to the tip side 27 as the tip.
The guard 23 is also made of a rigid, conductive metal and covers an area extending from the hub side 26 to the tip side 27 on the trailing edge 25 side of the fan blade body 21 .

The sheath 22 and guard 23 are originally parts for responding to bird strikes. In the fan blade 8 according to this embodiment, the sheath 22 and the guard 23 are separated so as not to come into contact with each other and are electrically insulated.

The fan blade 8 according to this embodiment, as shown in FIG. has a pair of leading edge side conducting portion 31 (first conducting portion) and trailing edge side conducting portion 32 (second conducting portion) for applying current to the conducting region of the fan blade main body 21 . It should be noted that the illustrated leading edge side conducting portion 31 and trailing edge side conducting portion 32 schematically show approximate positions, and the shape of the leading edge side conducting portion 31 and the trailing edge side conducting portion 32 are actually different (described later). ).

Here, in the fan blade 8 of the jet engine 1 of the aircraft, the rotation speed of the hub side 26 of the leading edge 24 is slow, so the amount of icing is the largest, and the rotation speed of the tip side 27 is high. Since the ice is easy to peel off, it tends to be difficult to accumulate. As such, the heating region 36 is typically located on the leading edge 24 side and closer to the hub side 26 . Anti-icing and anti-icing measures in this heating area 36 are important.

The leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 are located on the front edge 24 side and the trailing edge 25 side of the heating region 36, respectively, between the surface of the fan blade main body 21 and the back surface of the sheath 22, and the surface of the fan blade main body 21. and the rear surface of the guard 23.

The leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 have electrodes configured by removing the insulating coating from the ends of the

wires

33 and 34 with insulating coating, respectively, between the front surface of the fan blade main body 21 and the rear surface of the sheath 22 . , the front surface of the fan blade body 21 and the rear surface of the guard 23 are adhered via a paste-like conductive adhesive (not shown). Here, the fan blade main body 21 has carbon fiber exposed portions where the carbon fibers contained in the carbon fiber reinforced plastic are exposed at respective positions corresponding to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 . This carbon fiber exposed portion is configured by, for example, shaving the insulating epoxy resin at the portion to expose the conductive carbon fiber. In addition, by using a conductive adhesive, it becomes possible to efficiently pass an electric current through the carbon fibers. This indicates that resistance heating can be realized by forming a current path made of conductive carbon fiber based on the material configuration of the fan blade main body 21 .

A negative voltage, for example, is applied to the leading edge side conducting portion 31 from a power source 35 through an insulating coated wire 33, and a positive voltage, for example, is applied to the trailing edge side conducting portion 32 from a power source 35 through an insulating coated wire 34. A voltage is applied to the energized region of the fan blade main body 21 between the leading edge side energizing portion 31 and the trailing edge side energizing portion 32, and current flows, and the fan blade main body 21 itself generates heat due to the resistance. The area heated by heat generation includes the heating area 36, or the heating area 36 includes the area heated by heat generation.
A positive voltage may be applied to the leading edge side conducting portion 31 and a negative voltage may be applied to the trailing edge side conducting portion 32 .

In the fan blade 8 according to the present embodiment, the fan blade main body 21 is made of CFRP and is conductive, so the property of generating heat when an electric current flows is used. That is, a pair of front edge sides for passing an electric current through the current-carrying region of the fan blade main body 21 by applying an electric current to the carbon fibers contained in the CFRP on the front edge 24 side and the trailing edge 25 side of the fan blade main body 21 made of CFRP. A current-carrying portion 31 and a trailing-edge-side current-carrying portion 32 are provided, and a voltage is applied between them from a power supply 35 to flow current through the current-carrying region, thereby heating the fan blade body 21 and preventing or deicing the heating region 36. conduct. At that time, the heat generated by the CFRP itself (fan blade main body 21) and the heat flow spread through the CFRP (fan blade main body 21), and there is also heat transfer to the sheath 22 and the guard 23. Each heat acts as anti-icing and de-icing. Thereby, anti-icing and de-icing of the heating area 36 are performed.

The heating region 36 for anti-icing and de-icing by such heating can be adjusted by the positions at which the pair of leading edge side current-carrying portion 31 and trailing edge side current-carrying portion 32 are attached. That is, the

electric wires

33 and 34 with insulation coating are laid between the sheath 22 and the guard 23 and the fan blade body 21, and the electrodes at the tips of the

electric wires

33 and 34 with insulation coating and the fan blade body are aligned with the area to be heated. 21 is adjusted.

For example, for anti-icing or de-icing on the hub side 26 of the leading edge 24, the description of FIG. The positions of the electrodes (the first current-carrying portion 31 and the second current-carrying portion 32) on the front edge 24 side and the rear edge 25 side are set near the hub side 26. FIG. By doing so, the anti-icing and de-icing on the hub side 26 of the leading edge 24 side is efficiently carried out.

The leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 attach electrodes, which are formed by removing the insulating coating from the ends of the

wires

33 and 34 with insulating coating, respectively, to the target portion via a conductive adhesive (not shown). Since it is adhered to the Conductive adhesive differs from, for example, copper tape in which electrodes are attached, and the conductive material penetrates into the fine irregularities of the processed surface, increasing the conductive area, resulting in reduced resistance and easier current flow. , local temperature rise and conduction failure can be prevented, and power consumption can be suppressed. In addition, it has been confirmed that when the copper tape is used instead of the conductive adhesive, it hardly heats up even at the same voltage. In particular, when considering Joule heat, the current works in squares, so it is important to find a way to allow the current to flow with the same applied voltage. Therefore, it is considered that the effect of adhering the electrode and the fan blade main body 21 and the like with the conductive adhesive is great.

Further, in the fan blade 8 according to this embodiment, by changing the magnitude of the voltage or current supplied to the fan blade main body 21 through the

wires

33 and 34 with insulation coating, the heat generation temperature and the heat generation speed of the heating region 36 can be changed. can be adjusted.

3. Attaching the fan blade to the fan disk and supplying power

FIG. 6 is a perspective view showing a fan blade 8 attached to the fan disk 6, FIG. 7 is a diagram for explaining the wiring configuration for supplying power to the fan blade 8, and FIG. 4 is a diagram for explaining a configuration of power supply to blades 8. FIG.

As shown in FIG. 6, the fan disk 6 has locking grooves 41 in which the dovetails 7 attached to the fan blades 8 are locked. A gap is provided between the end surface of the dovetail 7 and the bottom of the locking groove 41 .

By inserting the dovetail 7 into the locking groove 41 from the front edge 24 side (see the arrow in FIG. 8) and sliding the fan blade 8 toward the rear edge 25 side, the dovetail 7 is locked in the locking groove 41 and the fan A blade 8 is attached to the fan disk 6 .
A dovetail 7 is attached to the hub side 26 of the fan blade 8 via a platform 43 and a shank 42, as shown in FIG.

Connection terminals

46 and 49 are attached to the end face of the dovetail 7 via insulating

sheets

46a and 49a on the front edge 24 side and the rear edge 25 side, respectively. The connection terminal 46 is connected to the front edge side conducting portion 31 on the front edge 24 side via the electric wire 33 with an insulation coating. The insulated wire 33 is wired on the platform 43 and the shank 42 on the front edge 24 side. The connection terminal 49 is connected to the trailing edge side current-carrying portion 32 on the trailing edge 25 side via the electric wire 34 with an insulating coating. The insulated wire 34 is routed on the platform 43 and the shank 42 on the trailing edge 25 side.

As shown in FIG. 8, on the bottom surface of the locking groove 41 of the fan disk 6, V-shaped contact fittings (connecting terminals) 51 and 51 are provided at positions corresponding to the connecting

terminals

46 and 49 via insulating

sheets

51a and 52a, respectively. 52 are provided.

When the dovetail 7 is locked in the locking groove 41 and the fan blade 8 is attached to the fan disk 6, the

connection terminals

46 and 49 contact and press the V-shaped

contact fittings

51 and 52, respectively. As a result, the

connection terminals

46, 49 and the V-shaped

contact fittings

51, 52 are brought into elastic contact with each other at the bottom of the locking groove 41 and the end face of the dovetail 7, respectively.

A battery 53 serving as a power source is accommodated in the spinner 5, and the battery 53 and the V-shaped

contact fittings

51, 52 are connected via the

electric wires

45, 48 with insulation coating passing through the fan disk 6 and the spinner 5, respectively. there is Thereby, electric power for heating is supplied to the fan blade main body 21 . By adopting such a configuration, the configuration for power supply can be simplified.

FIG. 9 is a diagram for explaining another configuration of power supply to the fan blades 8. FIG.

In this configuration, power for heating the fan blade main body 21 is supplied from the existing power supply system 62 which is external. In this configuration, a slip ring 61 is attached to the low-pressure shaft 2 which is a rotating shaft, and power for heating the fan blade body 21 is supplied from an existing power supply system 62 via the slip ring 61 . This makes it possible to supply power from the outside.

II. fan blade

1. Fan blade configuration (details)

Fig. 10 is an exploded view schematically showing the laminated prepregs that constitute the fan blade body.

The fan blade body 21 is an example composed of a plurality (n layers) of

laminated layers

211, 212, 213, 214, . . . 21n. Each

layer

211, 212, 213, 214, . Each

layer

211, 212, 213, 214...21n may be the same prepreg.

The orientations of the carbon fibers included in the multiple (n layers) layers 211, 212, 213, 214, . . . 21n are different. When the span direction (longitudinal direction) of the fan blade 8 is 0° and the cord direction (lateral direction) is 90°, the orientation of the carbon fibers contained in the layer 214 is 0°, and the carbon fibers contained in the layer 211 is 90°. Layer 212 includes carbon fibers oriented in a first direction (+45° in this example) that is positively angled with respect to both the span and cord directions. Layer 213 comprises carbon fibers oriented in a second direction (−45° in this example) that is negatively angled with respect to both the span and cord directions. Other layers 21n have a configuration in which a quasi-isotropic configuration in which carbon fibers are arranged with orientation directions of 90°, ±45°, 0°, or other angles is repeatedly laminated multiple times.

Even if the plurality of

layers

211, 212, 213, 214, . Show different values. Taking advantage of such properties, a quasi-isotropic lamination structure is used in which prepregs in which carbon fibers are oriented in one direction are used to change the orientation according to lamination in order to obtain a certain level of mechanical and mechanical properties in the outer peripheral direction. Specifically, the fan blade obtains the desired mechanical properties by repeatedly laminating a configuration in which the orientation directions of the carbon fibers are 90°, ±45°, and 0° with respect to the span direction (longitudinal direction). Although an example of pseudo-isotropy is shown in the same figure, it may not be pseudo-isotropic.

As described above, in the fan blade 8 of the jet engine 1 of the aircraft, the rotation speed is slow on the hub side 26 of the leading edge 24, so the amount of ice accretion is the largest, and the rotation speed on the tip side 27 of the trailing edge 25 is the highest. It tends to be difficult to accumulate ice because it is fast and easy to peel off due to centrifugal force and the like. In addition, as described above, voltage is applied to the current-carrying region of the fan blade body 21 between the leading edge-side current-carrying portion 31 and the trailing edge-side current-carrying portion 32, so that a current flows, and the fan blade body 21 itself is affected by the resistance. Fever. When a current is passed between the pair of leading edge-side current-carrying portion 31 and trailing edge-side current-carrying portion 32, the amount of heat generated on the front edge 24 side of the fan blade main body 21 is made higher than the amount of heat generated on the trailing edge 25 side. To increase the amount of heat generated on the front edge 24 side (more precisely, its hub side 26) of a main body 21, and to more efficiently prevent ice on the front edge 24 side (more precisely, its hub side 26). Furthermore, the fan blades 8 of the jet engine 1 tend to concentrate icing on the hub side 26 due to the rotation of the fan blades 8 regardless of the size of the fan blades 8 (regardless of the size of the engine). It is possible to obtain an effective anti-icing effect by means described in the embodiments.

Therefore, in this embodiment, when a current is passed between the pair of leading edge side current-carrying portion 31 and trailing edge side current-carrying portion 32, the amount of heat generated on the front edge 24 side of the fan blade main body 21 is less than the amount of heat generated on the trailing edge 25 side. To increase the density, the conductive fiber density on the leading edge 24 side of the fan blade body 21 is made higher than the conductive fiber density on the trailing edge 25 side. Specifically, the ratio of the carbon fibers conducted to the leading edge side current-carrying portion 31 to the length of the leading edge side current-carrying portion 31 in the span direction is the same as that of the trailing edge side current-carrying portion 32 to the length of the trailing edge side current-carrying portion 32 in the span direction. By making the proportion of carbon fibers that are conducted higher than that, the conducting fiber density on the leading edge 24 side becomes higher than the conducting fiber density on the trailing edge 25 side.

To achieve that difference in conducting fiber density, not only one or more layers 211 with a carbon fiber orientation of 90°, but also one or more layers 212 with a carbon fiber orientation of +45° and a carbon fiber orientation of One or more layers 213 at −45° are connected to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 . The spanwise length of the trailing edge side conducting portion 32 is set longer than the spanwise length of the leading edge side conducting portion 31 . On the other hand, focusing on the carbon fibers conducting to both the leading edge-side conducting portion 31 and the trailing edge-side conducting portion 32 (that is, the carbon fibers contained in the conducting region), the number of carbon fibers conducting to the leading edge-side conducting portion 31 and the number of carbon fibers conducting to the trailing edge-side conducting portion 31 The number of carbon fibers conducting to the edge-side conducting portion 32 is the same. Therefore, when the same number of carbon fibers are electrically connected to the short leading edge side current-carrying portion 31 and the long trailing edge side current-carrying portion 32, the leading edge side current-carrying portion 31 is electrically connected to the length (short) of the leading edge side current-carrying portion 31 in the span direction. The conducting fiber density on the side of the leading edge 24, which is the ratio of the carbon fibers that are connected to the trailing edge, is the ratio of the carbon fibers that are conducted to the trailing edge-side conducting portion 32 with respect to the length (long) of the trailing edge-side conducting portion 32 in the span direction. Higher than the conductive fiber density on the 25 side. Since the conducting fiber density on the leading edge 24 side is higher than the conducting fiber density on the trailing edge 25 side, when a current is passed between the pair of leading edge side conducting parts 31 and trailing edge side conducting parts 32, the leading edge of the fan blade main body 21 By making the amount of heat generated on the side 24 higher than the amount of heat generated on the side of the trailing edge 25, the temperature on the side of the leading edge 24 of the fan blade main body rises. The carbon fibers conducting on the leading edge 24 side exist in the same number in a narrower region than on the trailing edge 25 side. Therefore, the temperature on the leading edge 24 side becomes higher than on the trailing edge 25 side due to the heat generated by the carbon fibers themselves.

2. specimen

FIG. 11 schematically shows a lamination cross-section of a laminated prepreg specimen used in the experiment.

Prepare a laminated prepreg specimen. In this example, 24

layers

211, 212, 213, and 214 having carbon fiber orientations of 90°, +45°, -45°, and 0° are laminated symmetrically. This is only an example, for example layers with +30° to +60° orientation may be provided. For example, layers with -30° to -60° orientation may be provided. For example, layers with carbon fiber orientations of 90°, +60°, +30°, −30°, −60° and 0° may be provided. The layers may be laminated in a quasi-isotropic manner, or the proportion of layers that are not quasi-isotropic and oriented at, for example, 90° may be higher than layers oriented at other angles. In the laminated state, both ends of the plurality of

layers

211, 212, 213, 214, . The two end faces are, for example, a knife-edge shape consisting of two angled planes instead of one plane. The thickness of each

layer

211, 212, 213, 214...21n is, for example, 0.19 mm.

The first direction is +30° to +60°, and the second direction is −30° to −60° (that is, being acute), so that the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 can be made relatively short in the span direction. As a result, the resistivity increases due to the narrow application area of the conductive adhesive, and it becomes possible to increase the amount of heat generated by the resistance.

Fig. 12 shows a laminated prepreg specimen used in the experiment.

In the stacked state, both ends of the plurality of

layers

211, 212, 213, 214, . Therefore, one or more layers selected from the plurality of

layers

211, 212, 213, 214, . can. One layer 21n may be connected to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32, or a selected part of the layers 21n may be connected to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32, All layers 21n may be connected to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 . When applying a conductive adhesive to one or more layers 21n selected instead of all layers 21n, anisotropic conductive film materials and insulating materials (for example, masking tape in tests) used in high-density mounting of electronic components may be used.

FIG. 13 is a schematic diagram for explaining the conductive fiber density used in the experiment.

Type 2 is this embodiment, one or more layers 211 with a carbon fiber orientation of 90°, one or more layers 212 with a carbon fiber orientation of +45° and a carbon fiber orientation of -45°. One or more layers 213 are connected to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 . Specifically, a conductive adhesive is applied to all layers in FIG. The spanwise length 31L of the trailing edge side conducting portion 32 is longer than the spanwise length 31L of the leading edge side conducting portion 31 . On the other hand, focusing on the carbon fibers conducting to both the leading edge-side conducting portion 31 and the trailing edge-side conducting portion 32 (that is, the carbon fibers contained in the conducting region), the number of carbon fibers conducting to the leading edge-side conducting portion 31 and the number of carbon fibers conducting to the trailing edge-side conducting portion 31 The number of carbon fibers conducting to the edge-side conducting portion 32 is the same. Therefore, when the same number of carbon fibers are electrically connected to the short leading edge side current-carrying portion 31 and the long trailing edge side current-carrying portion 32, the leading edge side current-carrying portion 31 with respect to the length 31L (short) of the leading edge side current-carrying portion 31 in the span direction The ratio of the carbon fibers conducted is higher than the ratio of the carbon fibers conducted to the trailing edge side current-carrying portion 32 with respect to the length 32L (long) of the trailing edge side current-carrying portion 32 in the span direction. As a result, the conductive fiber density on the leading edge 24 side (area within the ellipse in the figure) is higher than the conductive fiber density on the trailing edge 25 side. The conductive fiber density on the leading edge 24 side is higher than the conductive fiber density on the trailing edge 25 side, so that the amount of heat generated on the front edge 24 side of the fan blade body 21 is higher than that on the trailing edge 25 side. The temperature on the leading edge 24 side of the blade body increases. The carbon fibers conducting on the leading edge 24 side exist in the same number in a narrower region than on the trailing edge 25 side. Therefore, the temperature on the leading edge 24 side becomes higher than on the trailing edge 25 side due to the heat generated by the carbon fibers themselves.

Type 1 is a comparative example, in which one or more layers 211 having carbon fibers oriented at 90° are connected to the leading edge side conducting portion 31A and the trailing edge side conducting portion 32A. Specifically, the conductive adhesive is applied only to the two layers (90° orientation) at the center in the thickness direction (center of symmetry) in FIG. It is connected to the portion 31 and the trailing edge side current-carrying portion 32 . Focusing on the carbon fibers conducting to both the leading edge side conducting portion 31A and the trailing edge side conducting portion 32A (that is, the carbon fibers contained in the conducting region), the number of carbon fibers conducting to the leading edge side conducting portion 31A and the trailing edge side conducting portion The number of carbon fibers conducting to the portion 32A is the same. Therefore, the conducting fiber density on the leading edge 24 side and the conducting fiber density on the trailing edge 25 side are the same.

Fig. 14 shows Type 1 and Type 2 specimens used in the experiment.

In FIG. 14, the area surrounded by lines is the area where fiber heating occurs due to conduction, and represents the area to be evaluated as an area when calculating the anti-icing effect. Prepare the above type 1 and type 2 specimens. Both type 1 and type 2 specimens are CFRP laminates having a size of 187 mm in the span direction, 58.6 mm in the cord direction, and 4.6 mm in the thickness direction. The type 1 specimen has a leading edge side conducting portion 31A (span direction length 30 mm) and a trailing edge side conducting portion 32A (span direction length 30 mm) at the mid-span position. Electricity is applied between the portions 32A. The type 2 specimen has a leading edge side conducting portion 31 (span direction length of 60 mm) and a trailing edge side conducting portion 32 (span direction length of 100 mm) at the mid-span position. The energized region between the portions 32 is energized. The leading edge side current-carrying portion 31A and the trailing edge side current-carrying portion 32A are made of a conductive adhesive. Type 1 and type 2 differ in the size of the heating area. A region surrounded by a straight line in the drawing is an energization region between the leading edge side energization portion 31A and the trailing edge side energization portion 32A, as well as a heating region and an evaluation region.

3. Test result 1

Fig. 15 shows an experimental icing wind tunnel.

The icing wind tunnel device 100 has a wind tunnel 110, a droplet catcher 106, a camera (not shown), and a refrigeration room 107 that houses them. The wind tunnel 110 includes, in order from upstream to downstream, a blower 101, a strainer grid 102, a spray tunnel 103, a contraction 104, and an air outlet 105, which is a test section. Spray tunnel 103 houses a plurality of spray nozzles 108 . A camera (not shown) photographs the test section, air outlet 105 . A camera (not shown) includes at least a thermo camera and may also include a camera for taking pictures. A droplet catcher 106 is installed downstream of the air outlet 105 .

The specifications of the icing wind tunnel device 100 are as follows. Maximum flow velocity 50m/s. Temperature -30 to -5°C. The volume of the refrigeration room 107 is 2500×4500×2400 mm ³ . The cross-sectional area of the spray tunnel 103 is 400×400 mm ² . The cross-sectional area of the air outlet 105 is 200×200 mm ² .

A specimen 109 is installed downstream of the air outlet 105, which is the test section. Air is passed through the wind tunnel 110 and droplets are sprayed from the spray nozzle 108 toward the specimen. There are two types of air flow velocity conditions, 20 m/s and 40 m/s. The conditions for the particle size of droplets sprayed from the spray nozzle 108 are two types of 15 μm and 29 μm.

Figures 16 and 17 are photographs showing the anti-icing test results.

FIG. 16 shows Type 1 and Type 2 anti-icing under the first test conditions (air flow rate 20 m/s, droplet size 15 μm, power (input power/area of heating area) 1.1 W/cm ² ). It is the photograph which image|photographed the specimen after a test with the camera.

FIG. 17 shows the anti-icing of Type 1 and Type 2 under the second test conditions (air velocity 40 m/s, droplet size 15 μm, power (input power/area of heating area) 0.83 W/cm ² ). It is the photograph which image|photographed the specimen after a test with the camera.

　Figures 18 and 19 are graphs showing the anti-icing test results.

The horizontal axis indicates the power, specifically the input power/the area of the heating region [w/cm ² ]. Type 1 and Type 2 differ in the size of the heating area, and cannot be simply compared based on input power. The vertical axis is the anti-icing effect (anti-ice effect) [%], which is calculated by the following formula.

In the above formula, A _anti-ice [mm ² ] is the average value of the ice accretion areas on the front and sides of the specimen after the anti-icing test. A _ice [mm ² ] is the average value of the ice accretion areas on the front and side surfaces of the specimen after the non-exothermic icing amount confirmation test. Ideally, these icing areas should be evaluated by icing weight. Evaluate by

FIG. 18 shows the results of an anti-icing test in which the air flow velocity was 20 m/s, the droplet diameter was 15 μm and 29 μm, and the input power was changed. At least when the power (input power/area of heating region) is 0.83 W/cm ² or more, the anti-icing effect of type 2 is higher than the anti-icing effect of type 1.

FIG. 19 shows the results of an anti-icing test in which the air flow velocity is 40 m/s, the droplet diameter is 15 μm and 29 μm, and the input power is varied. The anti-icing effect of type 2 is higher than the anti-icing effect of type 1 when the power (input power/area of heating area) is about 0.5 to 1.1 W/cm ² .

4. Test result 2

Fig. 20 is a thermography showing the results of the windless heat generation test.

Prepare specimens for Case 1 and Case 2. The specimens of case 1 and case 2 differ in the layers connected to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 . In the case 1 , all knife-edge surface layers are connected to the leading edge side conducting portion 31 and the trailing edge side conducting portion 32 . In the case 2, the layer (specifically, the two-layer portion of the central portion 211 in FIG. 11) formed in the central portion in the thickness direction of the selected one or more test pieces is the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32. connected to The specimens of Case 1 and Case 2 are placed in a windless room at a room temperature of 10°C, an input power of 10 W is applied for 30 seconds, and the bottom surface of the specimen is photographed with a thermo camera to obtain the surface temperature distribution.

Fig. 21 is a graph showing the results of the windless heat generation test.

This graph shows the cross-sectional temperature distribution at the center of the bottom surface of the specimen indicated by the dashed line in FIG. 20 30 seconds after the start of energization. The horizontal axis indicates the position of the specimen from the pressure side surface to the suction side surface at the position of the mid-cord. 5 pixels to 27 pixels on the horizontal axis correspond to the specimen portion. The vertical axis indicates cross-sectional temperature (°C).

Cases

1 and 2 differed in the heat generation of the cross section. It is considered that this also applies to confirmation during an anisotropic conductive film (ACF) test. The temperature of case 2 is higher than that of case 1 as a whole. The temperature of the front and rear edges of the case 2 is particularly high, and it is considered that the temperature rise of the mid-cord part was affected by this.

5. Choice of pressure and suction side layers

The icing on the fan blades 8 of the jet engine 1 of the aircraft is concentrated on the front edge 24 of the fan blade 8 (especially the area from the hub side 26 to the midspan) and the pressure surface. This phenomenon is caused by the difference in rotational circumferential speed between the hub side 26 and the tip side 27 . The hub side 26 of the front edge 24 has the slowest rotation speed, so the amount of ice accretion is the largest. At the same time that droplets in the atmosphere collide with the fan blades 8 , an icing mechanism of a supercooling phenomenon occurs in which the droplets freeze rapidly on the leading edge 24 and the pressure surface of the fan blades 8 .

Due to the above two factors, the icing that is concentrated on multiple locations unique to the fan blade 8 occurs. become important.

Therefore, it is desirable to actively heat the area near the midspan and the positive pressure surface from the leading edge 24 hub side 26 where a large amount of ice is deposited. As described above, voltage is applied to the current-carrying region of the fan blade main body 21 between the leading edge-side current-carrying portion 31 and the trailing edge-side current-carrying portion 32, causing current to flow and the fan blade body 21 itself to generate heat due to its resistance. .

For example, a 90° oriented layer across the leading edge 24 and the trailing edge 25 and a layer close to the anti-icing surface (positive pressure surface) are selected and energized. Alternatively, a current may be applied to the pressure surface and the suction surface to generate a temperature difference or a different heat generation region between the pressure surface and the suction surface. In order to generate different heat generating regions, the length of the conductive adhesive applied to the front and rear edges, the position of the applied adhesive, etc. may be offset. Also, the current may be applied to the pressure surface and not to the suction surface. Also, the pressure surface side may have more layers through which current flows than the suction surface side, and the number of conductive fibers themselves that generate heat may be increased on the pressure surface side. By selecting the layers that constitute the current path, the heat generation temperature or the heat generation region of the pressure surface and the suction surface are different, and as a result, anti-icing can be achieved with minimum power consumption. The heat generation area and heat generation temperature can be secured with the minimum applied power, and the heat generation temperature of the pressure side and the suction side of the fan blade main body 21 can be set. Specifically, the temperature of the pressure surface on which a large amount of ice adheres can be raised to a high temperature, and the temperature of the suction surface on which a small amount of ice adheres can be lowered. With this configuration, it is possible to advantageously function in the hollow structure that accompanies the recent weight reduction of fan blades. Furthermore, the fan blades 8 of the jet engine 1 tend to concentrate icing on the hub side 26 due to the rotation of the fan blades 8 regardless of the size of the fan blades 8 (regardless of the size of the engine). It is possible to obtain an effective anti-icing effect by means described in the embodiments.

6. Brief Summary

The minimum unit (component) that constitutes the fan blade main body 21 is the laminated prepreg. The prepreg layer has specifications including the types of resin and carbon fiber that constitute it, the content of carbon fiber and resin, and the thickness. In this embodiment, one or more layers are selected to be energized. The direction in which current flows in the CFRP structure through a pair of current paths between the ends of the carbon fibers of each carbon fiber layer arranged in a fixed direction in the CFRP lamination direction and the area that contributes to heat generation are specified. can do

From a microscopic point of view, the resistance component that excites the heat generation of CFRP is proportional to the length between both ends of the carbon fiber layer of the selected layer, and inversely proportional to the thickness of the selected prepreg layer and the carbon fiber content. For example, in a quasi-isotropic configuration in which layers are laminated with different orientations, the difference in the length of the carbon fibers due to the difference in the layers selected in the thickness direction changes the resistance component and the heat generation temperature. For this reason, in order to obtain heat generation for defrosting the fan blades, heat generation efficiency can be increased by preferentially selecting a layer with a short carbon fiber length orientation straddling the leading edge and trailing edge.

From a macroscopic point of view, the basic configuration of the fan blade 8 of the present embodiment includes a pair of leading edge side current-carrying portions 31 and trailing edge side current-carrying portions 32 electrically connected to the carbon fiber of the selected layer of the CFRP of the power source and the fan blade main body 21, It consists of a series circuit made up of the resistance component of the CFRP of the fan blade main body 21 . Therefore, the current flows uniformly in the circuit, and the current flowing according to each resistance component excites resistance heating, and the amount of heat generated is determined by the ratio of the resistance values of each resistance component. As for the selection of one or more layers, the selection of the carbon fiber layer that straddles the leading edge 24 and the trailing edge 25 of the fan blade 9 reduces the current path at the leading edge 24 (around the hub side 26) where icing concentrates. can be formed, and the heating area can be set.

A current path consisting of a combination of multiple carbon fiber orientation layers (for example, 90°, +45°, −45°) is formed with respect to the thickness direction of lamination, and the leading edge 24 is improved by increasing the conductive fiber density on the leading edge 24 side. An increase in the heat generation temperature and an expansion of the heat generation area on the surface of the fan blade 8 (pressure surface) can be expected.

III. conductive adhesive

1. Composition of conductive adhesive

Conductive adhesives are materials manufactured by dispersing particles of highly conductive metals such as silver, copper, and nickel in a solution of a binder resin such as a polymer. to form a flexible adhesive layer. The main functions of conductive adhesives are conductivity and adhesiveness, and the factors that determine the electrical and mechanical properties listed on the left include curing time, curing temperature, the content of metal particles such as silver, and the size of metal particles. and shape.

For example, as the curing time and temperature increase, the distribution between metal particles becomes denser, and the electrical resistance tends to decrease overall, but the adhesive strength increases. It is believed that this is because the solvent in the resin evaporates as the curing time increases, and the substrate and the paste form an intimate bond during curing.

Furthermore, conductive adhesives can be roughly divided into isotropic materials and anisotropic materials. Isotropic materials, like solder, conduct electricity in all directions, while anisotropic materials provide a unidirectional connection that allows current to flow only in the direction of compression between opposing electrodes. In the present invention, an anisotropic material and an isotropic material can be selectively used when selecting layers for forming current paths. When using an anisotropic conductive film, it is effective when selecting layers arranged in the direction of each laminated fiber for the purpose of improving the accuracy of current paths for a plurality of fan blades. The conductive adhesive is used to form a current path through the selected carbon fibers, but the resistance component of the conductive adhesive is mainly in the area passing through the point where ice is concentrated on the fan blade. By selecting the ratio of components to be equal, the heat generation effect and the anti-icing effect can be obtained predominantly.

In the present embodiment, when a current is passed between the pair of leading edge side current-carrying portion 31 and trailing edge side current-carrying portion 32, the amount of heat generated at the leading edge 24 side of the fan blade main body 21 is made higher than the amount of heat generated at the trailing edge 25 side. Therefore, the resistance value of the conductive adhesive that connects the fan blade main body 21 to the leading edge side conductive portion 31 (hereinafter referred to as the leading edge side conductive adhesive) connects the fan blade main body 21 to the trailing edge side conductive portion 32. It should be higher than the resistance value of the conductive adhesive (hereinafter referred to as trailing edge side conductive adhesive). For example, the resistance value of the leading edge side conductive adhesive used for the experiment is 3×10 ⁻³ to 8×10 ⁻⁴ Ω·cm, and the resistance value of the trailing edge side conductive adhesive is 8×10 ^{− 4} to 2×10 ⁻⁴ Ω·cm. As described above, the resistance component of the conductive adhesive uses metal particles with good conductivity to ensure conductivity. It can be selected according to the characteristics, and the resistance value described in the text is not limited. Combinations are possible in terms of the basic specifications required for fan blades and the current path configuration.

2. specimen

FIG. 22 schematically shows another specimen used in the experiment.

Prepare specimens for layout 1 and layout 2. The specimens of layout 1 and layout 2 differ in the type of conductive adhesive. Both the layout 1 and layout 2 specimens are CFRP laminates having a size of 187 mm in the span direction, 58.6 mm in the cord direction, and 4.6 mm in the thickness direction. The specimen has a leading edge side conducting portion 31A (span direction length 30 mm) and a trailing edge side conducting portion 32 (span direction length 30 mm) at the mid-span position. Energize the energized area between The leading edge side current-carrying portion 31 is connected to the leading edge LE of the specimen using a leading edge side conductive adhesive. The trailing edge side current-carrying portion 32 is connected to the trailing edge TE of the specimen using a trailing edge side conductive adhesive. In both layout 1 and layout 2 specimens, the leading edge side conductive adhesive and the trailing edge side conductive adhesive are applied to all the laminated prepregs, and all the laminated prepregs are connected to the leading edge side current-carrying portion 31 and the trailing edge side. It is connected to the conducting portion 32 . A region surrounded by a straight line in the figure is a current-carrying region between the leading edge-side current-carrying portion 31 and the trailing edge-side current-carrying portion 32, and at the same time, a heating region and an evaluation region.

Layout 2 is the present embodiment, and the types of the leading edge side conductive adhesive and the trailing edge side conductive adhesive are different. The resistance value of the leading edge side conductive adhesive is higher than the resistance value of the trailing edge side conductive adhesive. Specifically, the resistance value of the leading edge side conductive adhesive is 3×10 ⁻³ to 8×10 ⁻⁴ Ω·cm, and the resistance value of the trailing edge side conductive adhesive is 8×10 ⁻⁴ to Ω·cm. It is 2×10 ⁻⁴ Ω·cm.

Layout 1 is a comparative example in which the types of the leading edge side conductive adhesive and the trailing edge side conductive adhesive are the same. Specifically, the resistance values of the leading edge side conductive adhesive and the trailing edge side conductive adhesive are 3×10 ⁻⁴ to 5×10 ⁻⁵ Ω·cm.

3. Test result 1

FIG. 23 is a thermography showing test results.

The specimens of layout 1 and layout 2 are installed in the icing wind tunnel device 100, and air is flowed at an air velocity of 40 m/s. The same input power (40 W) is applied to the specimens of layout 1 and layout 2, and the surface temperature distribution is obtained by photographing the specimens with a thermo camera.

FIG. 24 is a graph showing test results.

This graph shows the surface temperature distribution of the specimen at the mid-span position indicated by the dashed line in FIG. The horizontal axis indicates the position of the specimen from the leading edge (0) to the trailing edge (1). The vertical axis indicates the surface temperature (°C). Although the input power is the same, the layout 2 can achieve a higher temperature than the layout 1 over the entire area, and the leading edge LE can achieve a higher temperature than the trailing edge TE. Also, in layout 1, the leading edge is deprived of heat due to the convection effect, and the temperature of the trailing edge is higher. On the other hand, layout 2 achieves a higher temperature at the leading edge than at the trailing edge despite the same test conditions.

　Figures 25, 26, 27 and 28 are photographs showing the test results.

FIG. 25 shows the results of the anti-icing test for layout 1 and layout 2 under the first test conditions (air flow velocity 20 m/s, droplet diameter 15 μm, input power (10 W, 20 W, 40 W). This is a photo taken in

FIG. 26 shows the results of anti-icing tests for

layouts

1 and 2 under the second test conditions (air flow velocity 20 m/s, droplet diameter 29 μm, input power (10 W, 20 W, 40 W). This is a photo taken in

FIG. 27 shows the results of the anti-icing test for layout 1 and layout 2 under the third test conditions (air flow velocity 40 m/s, droplet diameter 15 μm, input power (20 W, 30 W, 50 W). This is a photo taken in

FIG. 28 shows the results of anti-icing tests for

layouts

1 and 2 under the fourth test conditions (air flow velocity 40 m/s, droplet diameter 29 μm, input power (20 W, 30 W, 50 W). This is a photo taken in

　Figures 29 and 30 are graphs showing test results.

The horizontal axis indicates input power [w]. The vertical axis represents the anti-icing effect (anti-ice effect) [%], which is calculated by the above formula (Equation 1).

Fig. 29 shows test results with multiple changes in air flow velocity of 20 m/s, droplet diameters of 15 µm and 29 µm, and input power. The anti-icing effect of layout 2 is higher than the anti-icing effect of layout 1 at all input powers. Although it is impossible for the anti-icing effect to be negative, the variation was large in layout 1, and as a result of averaging, a negative value was generated for the anti-icing effect.

Fig. 30 shows test results with air flow velocity of 40 m/s, droplet diameters of 15 µm and 29 µm, and multiple changes in input power. The anti-icing effect of layout 2 is higher than the anti-icing effect of layout 1 at all input powers. Although it is impossible for the anti-icing effect to be negative, the variation was large in layout 1, and as a result of averaging, a negative value was generated for the anti-icing effect.

4. Test result 2

FIG. 31 is a thermography showing test results.

Prepare specimens for layout 3 and layout 4. Both the specimens of layout 3 and layout 4 are CFRP laminates having a size of 187 mm in the span direction, 58.6 mm in the cord direction, and 4.6 mm in the thickness direction. The specimen has a leading edge side conducting portion 31 (span direction length 30 mm) and a trailing edge side conducting portion 32 (span direction length 30 mm) at the mid-span position. Energize the energized area between In layout 3, the leading edge side conductive adhesive and the trailing edge side conductive adhesive are applied to all the laminated prepregs, and all the laminated prepregs are connected to the leading edge side conducting portion 31 and the trailing edge side conducting portion 32. be. In layout 4, the leading edge side conductive adhesive and the trailing edge side conductive adhesive are applied only to the two layers (90° orientation) at the center in the thickness direction (the center of symmetry), and the two layers at the center in the thickness direction are conductive to the leading edge side. It is connected to the portion 31 and the trailing edge side current-carrying portion 32 . In this test, the lengths in the span direction of the leading edge side conducting portion 31 and the trailing edge side conducting portion 32 of the

layouts

3 and 4 were 30 mm (same as above). The specimens of layout 3 and layout 4 were installed in the icing wind tunnel apparatus 100, the room temperature was set to -10°C, and the air flow rate was 20 m/s. The same input power (20 W) is applied to the specimens of layout 3 and layout 4 for 90 seconds, and after 90 seconds from the start of energization, the specimens are photographed with a thermo camera to obtain the surface temperature distribution.

Fig. 5 is a graph showing test results.

This graph shows the surface temperature distribution of the specimen at the mid-span position indicated by the dashed line in FIG. The horizontal axis indicates the position of the specimen from the leading edge (0) to the trailing edge (1). The vertical axis indicates the surface temperature (°C) 90 seconds after the start of energization. Layout 4 had a temperature distribution in which heat generation at the front and rear edges was higher than layout 3 over the entire area. The reason for this is thought to be that in layout 4, the application area S of the conductive adhesive is small (the thickness of the conductive adhesive is the same), so the resistance R [Ω] increases and the amount of heat increases. be done.
In layout 3, the temperature of the leading edge could be higher than that of the trailing edge even during ventilation, but in layout 4, the temperature of the trailing edge was higher than that of the leading edge. In layer selection, the applied area of the conductive adhesive was reduced, so the leading edge conductive adhesive used this time had insufficient resistance to heat loss due to convective heat transfer, resulting in this result. However, the volume of the conductive adhesive on the leading edge can be reduced (when the applied area of the conductive By increasing the resistance value of the trailing edge), it is possible to raise the temperature of the leading edge more than the trailing edge even by layer selection.
By the way, it has been confirmed that the temperature on the leading edge side of the layout 4 is higher than that on the trailing edge side in the same way as the layout 3 under normal temperature and no wind conditions.

　R = (ρL)/S

By reducing the volume of the conductive adhesive at the front edge (reducing the coating thickness when the application area of the conductive adhesive is assumed to be the same) as described above, the temperature at the front edge can be adjusted later in layer selection. The following test results were obtained for "It is possible to lift from the edge".
FIG. 40 shows the front and rear edges of the front and rear edges with different coating thicknesses of the conductive adhesive (150 μm, 300 μm, 400 μm, the front and rear edges are the same thickness) under the conditions of −10° C., no wind, and 10 W input power. It is the graph which measured the resistance value between. As shown in the graph of FIG. 40, the smaller the coating thickness, the larger the resistance.
FIG. 41 shows the temperature distribution on the side surface of the CFRP specimen obtained with a thermo camera under the same test conditions as in FIG. This result also shows that the temperature of both the front and rear edges is high due to the reduction in the coating thickness. It is considered that this is because the resistance was increased by reducing the coating thickness as shown in FIG. The reason why the resistance increased when the coating thickness was reduced is thought to be that the current flowed more difficultly and the resistance increased. This is similar to when the volume of the conductive adhesive is reduced by reducing the coating thickness, resulting in a reduction in the coating area.

5. Selection of Pressure Side and Suction Side Conductive Adhesive A large amount of ice adheres and concentrates on the pressing surface. This phenomenon is caused by the difference in rotational circumferential speed between the hub side 26 and the tip side 27 . The hub side 26 of the front edge 24 has the slowest rotation speed, so the amount of ice accretion is the largest. At the same time that droplets in the atmosphere collide with the fan blades 8 , an icing mechanism of a supercooling phenomenon occurs in which the droplets freeze rapidly on the leading edge 24 and the pressure surface of the fan blades 8 .

Therefore, it is desirable to actively heat the area near the midspan and the positive pressure surface from the leading edge 24 hub side 26 where a large amount of ice is deposited. As described above, voltage is applied to the current-carrying region of the fan blade main body 21 between the leading edge-side current-carrying portion 31 and the trailing edge-side current-carrying portion 32, causing current to flow and the fan blade body 21 itself to generate heat due to its resistance. . Therefore, when a current is passed between the pair of leading edge side current-carrying portion 31 and trailing edge side current-carrying portion 32, the amount of heat generated on the pressure side of the fan blade main body 21 is higher than that on the suction side of the fan blade main body 21. is desirable.

As described above, for this reason, the leading edge/pressure surface (highest value), the leading edge/suction surface, the trailing edge/suction surface, the trailing edge/positive It is better to use the pressure surface (minimum value). For example, the resistance value of the leading edge side conductive adhesive on the pressure side of the fan blade body 21 may be higher than the resistance value of the leading edge side conductive adhesive on the suction side of the fan blade body 21 . The resistance value of the trailing edge side conductive adhesive on the suction surface side of the fan blade body 21 may be higher than the resistance value of the trailing edge side conductive adhesive on the pressure side side of the fan blade body 21 .

In addition to the size of the resistance value of the conductive adhesive, the application amount of the conductive adhesive ( The resistance of each part of the fan blade main body 21 can be changed also by the volume), the area bonded to the carbon fiber, and the size of the current path (the cross-sectional area of the path).

IV. layer selection

As described with reference to FIG. 11, in the laminated state, both ends of the plurality of

layers

211, 212, 213, 214, . For this reason, one or more layers selected from a plurality of layers 211 (90° orientation), 212 (+45° orientation), 213 (-45° orientation), 214 (0° orientation) . In addition, it can be connected to the leading edge side conducting portion 31 and the trailing edge side conducting portion 32 via a conductive adhesive. One layer 21n may be connected to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32, or a selected part of the layers 21n may be connected to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32, All layers 21n may be connected to the leading edge side current-carrying portion 31 and the trailing edge side current-carrying portion 32 .

1. Layer selection ventilation temperature confirmation test

FIG. 32 shows a specific example of layer selection used in the experiment.

Prepare four types of specimens. Layout 1 conducts all 90° layers by smearing conductive adhesive on all exposed layers. Layer selection A assumes that the temperature of the front edge of the specimen is raised, and conducts the two layers of the 90° layer in the center of the specimen. In layer selection B, it is assumed that the temperature on the surface side of the test piece is raised, and the two layers of the 90° layer close to the surface layer are conducted. Layer selection C (second layer side) assumes that the temperature of only one side corresponding to the pressure side is raised while raising the temperature of the leading edge, and one of the 90° layers in the center of the specimen and the surface layer (pressure side ), one of the 90° layers close to ), a total of two layers, are electrically connected. Layer selection C (1st layer side) raises the temperature of the front edge and makes the temperature of one side corresponding to the suction side lower than the pressure side, so only one of the 90° layers in the center of the specimen is conductive. do.

All the specimens have a leading edge side conducting portion 31 (span direction length 30 mm) and a trailing edge side conducting portion 32 (span direction length 30 mm) at the mid-span position. 32 is energized. The resistance value of the leading edge side conductive adhesive used for the experiment is 3×10 ⁻³ to 8×10 ⁻⁴ Ω·cm, and the resistance value of the trailing edge side conductive adhesive is 8×10 ⁻⁴ to Ω·cm. It is 2×10 ⁻⁴ Ω·cm. Check the surface temperature distribution of the specimen during ventilation under the conditions of 20 m/s of main stream speed, 9 W of input power, -10°C room temperature, and 90 seconds of input time.

Fig. 33 is a thermography showing the results of the layer selection ventilation temperature confirmation test. FIG. 34 is a graph showing the results of the layer selection ventilation temperature confirmation test.

The vertical axis of the graph of FIG. 34 is the surface temperature of the mid-span dashed line portion of the thermography of FIG. The horizontal axis is the cord length dimensionless from the leading edge to the trailing edge of the specimen.

Any layer selection can make the leading edge temperature higher than Layout 1 (solid coating). In particular, layer selection A and layer selection C (two-layer side) have conduction between the two layers of the front edge, so the front edge can be heated intensively and the temperature of the front edge can be increased. . Since layer selection B is the closest to the surface layer, the temperature around the mid-cord of the specimen can be made the highest. Comparing layer selection C (2nd layer side) and layer selection C (1st layer side), layer selection C (2nd layer side) allows two-layer conduction near the leading edge and surface, so layer selection C (1 layer side), the temperature can be raised over the entire area. By layer selection, the temperature of the front edge is efficiently raised, and when one side of the specimen surface is assumed to be the pressure side and the other side is assumed to be the suction side, the pressure side (layer selection C (2nd layer side)) can be made higher than the temperature of the suction surface (layer selection C (first layer side)). Layout 1 (solid coating) was able to make the temperature of the leading edge higher than the trailing edge even during ventilation, but the temperature of the trailing edge was higher than that of the leading edge in layer selection A and layer selection C (2nd layer side and 1st layer side). became. In layer selection, the applied area of the conductive adhesive was reduced, so the leading edge conductive adhesive used this time had insufficient resistance to heat loss due to convective heat transfer, resulting in this result. However, the reduction in the volume of the adhesive (if the application area of the conductive adhesive is considered to be the same, the application thickness is reduced), the ratio of the resistance of the front and rear edges (resistance value of the leading edge / resistance value of the trailing edge) By increasing the layer selection, it is possible to raise the temperature of the leading edge more than the trailing edge. By the way, it has been confirmed that the temperature on the leading edge side is higher than on the trailing edge side for layer selection A and layer selection C (layer 2 side and layer 1 side) as well as Layout 1 (solid coating) under normal temperature and no wind conditions.

Fig. 35 is a graph showing the results of the layer selection ventilation temperature confirmation test.

　Confirm the surface temperature distribution of the specimen during ventilation under the conditions of a main stream speed of 20 m/s, an input power of 20 W, a room temperature of -10°C, and an input time of 90 seconds. The only difference between FIG. 35 and FIG. 34 is the input power. The same function as when the input power is 9W can be realized even when the input power is 20W. Layout 1 (solid coating) was able to make the temperature of the leading edge higher than the trailing edge even during ventilation, but the temperature of the trailing edge was higher than that of the leading edge in layer selection A and layer selection C (2nd layer side and 1st layer side). became. In layer selection, the applied area of the conductive adhesive was reduced, so the leading edge conductive adhesive used this time had insufficient resistance to heat loss due to convective heat transfer, resulting in this result. However, the reduction in the volume of the adhesive (when the application area of the conductive adhesive is considered to be the same, the application thickness is reduced), the ratio of the resistance of the front and rear edges (resistance value of the leading edge ÷ resistance value of the trailing edge) By increasing the layer selection, it is possible to raise the temperature of the leading edge more than the trailing edge. By the way, it has been confirmed that the temperature on the leading edge side is higher than on the trailing edge side for layer selection A and layer selection C (layer 2 side and layer 1 side) as well as Layout 1 (solid coating) under normal temperature and no wind conditions.

2. Layer selective anti-icing test

A specimen of layout 1 and layer selection A in FIG. 32 is prepared. The test conditions were: mainstream speed 20m/s, 40m/s, droplet diameter 15μm, input power 20m/s (10W, 22W, 40W), 40m/s (20W, 30W, 49W), room temperature -10°C. be.

　Figures 36 and 37 are photographs showing the test results.

FIG. 36 shows the results of the anti-icing test for layout 1 and layer selection A under the test conditions (air flow velocity 20 m/s, droplet diameter 15 μm, input power (10 W, 22 W, 40 W). This is a photo.

FIG. 37 shows the results of anti-icing tests for layout 1 and layer selection A under different test conditions (air velocity 40 m/s, droplet size 15 μm, input power (20 W, 30 W, 49 W). This is a photo taken in

　Figures 38 and 39 are graphs showing test results.

FIG. 38 shows the results of FIG. 36, showing test results at an air flow rate of 20 m/s, a droplet diameter of 15 μm, and input power of 10 W, 22 W, and 40 W. At input powers of 22 W and 40 W, the anti-icing effect of layer selection A is higher than the anti-icing effect of layout 1 .

FIG. 39 shows the results of FIG. 37, showing test results with an air flow rate of 40 m/s, a droplet diameter of 15 μm, and input power of 10 W, 22 W, and 40 W. At input powers of 30 W and 49 W, the anti-icing effect of layer selection A is higher than the anti-icing effect of layout 1 .

In both FIGS. 38 and 39, it is difficult to see a difference in the effect at low power and at places where the input power is large and the anti-icing effect reaches its limit. Although the anti-icing effect is worse, when the entire test piece is weighed as "Icing weight [g]" including the icing that is not in the evaluation area, the icing weight during anti-icing is measured. Selection A provides a higher anti-icing effect. It is thought that due to the area calculation, a disadvantageous result was obtained due to the way the ice grew. The anti-icing effect of layer selection A is greater than that of layout 1 (solid coating) even with the same input power.

　V. Conclusion

This embodiment is based on CFRP, which has excellent mechanical properties and has been adopted for fan blades in recent years. According to this embodiment, it is possible to perform anti-icing and de-icing efficiently with a simple structure. In addition, by making it possible to implement the anti-icing function of the fan blades with a minimum of simple additional work, long-term stability and durability of the high anti-icing effect can be obtained without adversely affecting the original aerodynamic performance.

In this embodiment, it is possible to develop resistive heating especially in places where ice buildup is high using current fan blade specifications (CFRP). It is possible to develop by concentrating the resistance heating on the place where much icing occurs. Anti-icing function can be achieved with minimal additional processing, maintenance is easy, and long-term stability is ensured. and other advantageous effects.

The market size of the aircraft industry is expanding year by year, and the application rate of CFRP is increasing for both airframes and engines. Anti-icing and de-icing technology in the aviation industry has not changed much from the past, but CFRP is applied to parts that used metal, and development of new anti-icing and de-icing technology is expected. In the present embodiment, the characteristics of CFRP are utilized, and anti-icing and de-icing can be achieved by adding additional work to an existing CFRP fan without adversely affecting aerodynamics. In addition, it can be applied to wind turbines used for wind power generation, etc., which have the same problem of icing as in the aviation industry, and to prevent icing in cold regions in the automobile industry, where CFRP is becoming more and more popular.

Although the embodiments and modifications of the present technology have been described above, the present technology is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present technology. Of course.

1 : Jet engine 2 : Low pressure shaft 4 : Air intake 5 : Spinner 6 : Fan disk 7 : Dovetail 8 : Fan blade 21 : Fan blade body 22 : Sheath 23 : Guard 24 : Leading edge 25 : Trailing edge 31 : Leading edge side energization Portion 32 : Trailing edge side conducting portion 35 : Power source 36 : Heating region 41 : Locking groove 46 : Connection terminal 49 : Connection terminal 53 : Battery 61 : Slip ring

Claims

A fan blade arranged on the intake side of an engine,
a fan blade body made of carbon fiber reinforced plastic;
a pair of first current-carrying parts and second current-carrying parts for causing current to flow through the current-carrying region of the fan blade main body by causing current to flow through carbon fibers contained in the carbon fiber reinforced plastic;
and
When a current is passed between the pair of the first current-carrying portion and the second current-carrying portion, the amount of heat generated in the current-carrying region of the fan blade body on the first side of the fan blade body is the second level of the fan blade body. higher than the calorific value of the energized area on the side of the fan blade.
A fan blade according to claim 1, comprising:
The calorific value of the energized region on the first side of the fan blade body is higher than the calorific value of the energized region on the second side,
The conductive fiber density on the first side, which is the ratio of the carbon fibers conductively connected to the first conductive portion to the length of the first conductive portion in the span direction, is the length of the second conductive portion in the span direction. higher than the conducting fiber density on the second side, which is the ratio of carbon fibers conducted to the second current carrying portion to the thickness of the fan blade.
A fan blade according to claim 2, wherein
The fan blade body includes a plurality of laminated layers, and the carbon fibers contained in the plurality of layers have different orientations,
By connecting one or more layers selected from the plurality of layers to the first conductive portion and the second conductive portion, the conductive fiber density on the first side is higher than the conductive fiber density on the second side. high fan blades.
A fan blade according to any one of claims 1 to 3,
The one or more layers connected to the first current-carrying part and the second current-carrying part,
a first layer comprising carbon fibers oriented in a first direction positively inclined with respect to both the span direction and the cord direction; and/or negatively inclined with respect to both the span direction and the cord direction. A fan blade comprising a second layer comprising carbon fibers oriented in a second direction.
A fan blade according to any one of claims 1 to 4,
The length of the second conductive portion in the span direction is longer than the length of the first conductive portion in the span direction. Fan blade.
A fan blade according to any one of claims 1 to 5,
The fan blade body includes a plurality of laminated layers,
a layer on the pressure side selected from the plurality of layers is connected to the first conducting portion and the second conducting portion;
A fan blade according to claim 1, wherein an amount of heat generated on the pressure surface side of the fan blade body is higher than that on the suction surface side of the fan blade body when a current is passed between the pair of the first current-carrying portion and the second current-carrying portion.
A fan blade according to any one of claims 1 to 6,
a first side conductive adhesive and a second side conductive adhesive that connect the fan blade body to the first conductive portion and the second conductive portion;
The calorific value of the energized region on the first side of the fan blade body is higher than the calorific value of the energized region on the second side,
wherein the resistance value of the first side conductive adhesive is higher than the resistance value of the second side conductive adhesive.
A fan blade according to claim 7, comprising:
The fan blade body includes a plurality of laminated layers,
The first side conductive adhesive and the second side conductive adhesive connect one or more layers selected from the plurality of layers to the first current-carrying portion and the second current-carrying portion. Fan Blade .
A fan blade according to claim 7 or 8,
The resistance value of the first side conductive adhesive on the pressure side of the fan blade body is higher than the resistance value of the first side conductive adhesive on the suction side of the fan blade body,
A resistance value of the second side conductive adhesive on the pressure side is lower than a resistance value of the second side conductive adhesive on the suction side. Fan blade.
A fan blade according to any one of claims 1 to 9,
the first side is a leading edge side of the fan blade body;
The second side is a trailing edge side of the fan blade body. Fan blade.
a rotating shaft;
a fan disk provided on the inlet side of the rotating shaft;
A fan blade according to any one of claims 1 to 10, which is detachably attached to the fan disk;
A first current-carrying part and a second current-carrying part are provided on the fan disk side and the fan blade side, respectively, and when the fan blade is attached to the fan disk, they are electrically connected to each other on the fan disk side. a pair of connection terminals for energizing the power source and the first current-carrying part and the second current-carrying part;
engine with
a plate-shaped member made of carbon fiber reinforced plastic and having an icing area due to gas flow;
Provided on the first side and the second side of the plate-shaped member so as to include the icing region, current is passed through the carbon fiber contained in the carbon fiber reinforced plastic, and the current is passed through the current-carrying region of the plate-shaped member. A pair of first current-carrying part and second current-carrying part for flowing the
and
A structure with an anti-icing/deicing function, wherein the amount of heat generated in the energized area on the first side of the plate member is higher than the amount of heat generated by the energized area on the second side.