US20170248077A9 - Aircraft - Google Patents
Aircraft Download PDFInfo
- Publication number
- US20170248077A9 US20170248077A9 US14/552,605 US201414552605A US2017248077A9 US 20170248077 A9 US20170248077 A9 US 20170248077A9 US 201414552605 A US201414552605 A US 201414552605A US 2017248077 A9 US2017248077 A9 US 2017248077A9
- Authority
- US
- United States
- Prior art keywords
- cooler
- engine
- engine oil
- fan
- oil cooler
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000010705 motor oil Substances 0.000 claims abstract description 102
- 238000001816 cooling Methods 0.000 claims abstract description 10
- 230000002093 peripheral effect Effects 0.000 claims description 9
- 239000000446 fuel Substances 0.000 description 13
- 238000009434 installation Methods 0.000 description 9
- 230000007246 mechanism Effects 0.000 description 6
- UJCHIZDEQZMODR-BYPYZUCNSA-N (2r)-2-acetamido-3-sulfanylpropanamide Chemical compound CC(=O)N[C@@H](CS)C(N)=O UJCHIZDEQZMODR-BYPYZUCNSA-N 0.000 description 4
- 241001669680 Dormitator maculatus Species 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000009423 ventilation Methods 0.000 description 3
- 239000000470 constituent Substances 0.000 description 2
- 238000004378 air conditioning Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
- F02C7/12—Cooling of plants
- F02C7/14—Cooling of plants of fluids in the plant, e.g. lubricant or fuel
- F02C7/141—Cooling of plants of fluids in the plant, e.g. lubricant or fuel of working fluid
- F02C7/143—Cooling of plants of fluids in the plant, e.g. lubricant or fuel of working fluid before or between the compressor stages
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
- F02C7/12—Cooling of plants
- F02C7/16—Cooling of plants characterised by cooling medium
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T50/00—Aeronautics or air transport
- Y02T50/60—Efficient propulsion technologies, e.g. for aircraft
Definitions
- the present invention relates to an aircraft including a turbofan engine, and more particularly, to arrangement of an engine oil cooler and a pre-cooler.
- a turbofan engine of an aircraft includes a fan that is rotated by power produced by the engine.
- air is distributed into an engine body and a bypass flow path formed on the inner side of a nacelle. Air passing through the bypass flow path and air discharged from a nozzle of the engine body join together to be ejected backward. Thrust is obtained by the reaction of the jet stream.
- the engine is equipped with various accessories, such as a fuel control unit, a fuel pump, an igniter, and a plurality of heat exchangers.
- the accessories are provided around, above and below the engine and the fan within the nacelle.
- Examples of the accessories include a pre-cooler that cools bleed air from the engine so as to use the bleed air for a cabin air-conditioner or the like (Japanese Patent No. 4805352), and an engine oil cooler that cools engine oil.
- Both the engine oil cooler and the pre-cooler are heat exchangers that use the air flowing through the bypass flow path (hereinafter, referred to as a fan stream) as a heat source (a low-temperature source) in the turbofan engine.
- the fan stream is sucked therein from the bypass flow path, and exhausted after heat exchange with the engine oil and the engine bleed air.
- the engine oil cooler and the pre-cooler mounted to the turbofan engine are preferably provided at positions where the fan stream can be sufficiently introduced.
- the pre-cooler is provided in an upper portion within the bypass flow path of the engine body.
- the engine oil cooler is preferably arranged at a circumferentially different position from the pre-cooler, such as a position lateral to the engine body, so as to sufficiently introduce the fan stream therein without being disturbed by the pre-cooler.
- the engine oil cooler or the pre-cooler cannot be provided at a favorable position since its installation space is limited due to interference with another accessory or the like.
- the accessories are concentrated around the engine body.
- the installation space is greatly limited.
- the diameter of the nacelle is increased with respect to the diameter of the engine body, a required flow rate can be ensured.
- the diameter of the nacelle may not be enlarged in some cases.
- the nacelle diameter can be enlarged by increasing the length of a main landing gear. However, a weight increase is caused, and the fuel consumption is deteriorated.
- an object of the present invention is to provide an aircraft including a turbofan engine which can secure a heat exchange capacity of each of an engine oil cooler and a pre-cooler while avoiding a deterioration in fuel consumption even when an accessory installation space is limited.
- An aircraft of the present invention is an aircraft including a turbofan engine provided with an engine body and a fan located anterior to the engine body, further including: an engine oil cooler that is a heat exchanger for cooling engine oil used in the engine body by using, as a heat source, a fan stream flowing from the fan into a gap between a core cowl surrounding the engine body and a nacelle surrounding the fan and the core cowl; and a pre-cooler that is a heat exchanger for cooling bleed air from the engine body by using the fan stream as a heat source.
- an engine oil cooler that is a heat exchanger for cooling engine oil used in the engine body by using, as a heat source, a fan stream flowing from the fan into a gap between a core cowl surrounding the engine body and a nacelle surrounding the fan and the core cowl
- a pre-cooler that is a heat exchanger for cooling bleed air from the engine body by using the fan stream as a heat source.
- the engine oil cooler and the pre-cooler are longitudinally arranged in one position (one region) in a circumferential direction of the nacelle, and the engine oil cooler is located anterior to the pre-cooler.
- the engine oil cooler and the pre-cooler are arranged in the one position in the circumferential direction in a concentrated manner.
- a region where the engine oil cooler and the pre-cooler work as resistance to block the fan stream is limited to the one position in the circumferential direction.
- the engine oil cooler having higher importance for surely operating the engine body is arranged anterior to the pre-cooler, and the pre-cooler is arranged posterior to the engine oil cooler.
- the fan stream can be sufficiently introduced into the engine oil cooler from the front regardless of the existence of the pre-cooler.
- the engine oil cooler works as resistance against the fan stream for the pre-cooler that is arranged posterior to the engine oil cooler.
- the pre-cooler introduces the fan stream from the diagonally front by avoiding interference with the engine oil cooler that is arranged anterior to the pre-cooler, it is difficult to introduce the fan stream into the pre-cooler from the front.
- Introducing the fan stream into the pre-cooler from the diagonally front is disadvantageous in introducing the fan stream since a pressure loss is larger than that of a case in which the fan stream is introduced from the front.
- the fan stream can be introduced sufficiently enough to secure the heat exchange capacity of the pre-cooler by appropriately designing the positions, forms or the like of an intake port, an exhaust port, and a duct of the pre-cooler.
- the failure is not as serious as that of a case in which a failure occurs in the engine when the engine oil is insufficiently cooled, and can be treated by an airframe-side system.
- the heat exchange capacity of each of the engine oil cooler and the pre-cooler can be secured even when there is a limitation to an installation space for accessory machinery.
- the fuel consumption can be also improved.
- the engine oil cooler and the pre-cooler may be longitudinally arranged between a pylon that supports the turbofan engine on a main wing, and the engine body.
- the nacelle and the core cowl are each divided into right and left portions.
- the engine oil cooler and the pre-cooler can be arranged in an engine access space that is prepared in a gap where left side portions and right side portions of the nacelle and the core cowl face each other on the upper side where a hinge is located.
- the engine oil cooler and the pre-cooler may be supported on the pylon.
- the engine oil cooler may introduce the fan stream from a front.
- the fan stream is allowed to smoothly flow into the engine oil cooler directly from the fan.
- a plurality of block members that block passage of the fan stream when a thrust reverser that generates a portion of thrust to a front side is operated may be arranged at intervals in a circumferential direction, and the pre-cooler may introduce the fan stream passing through a gap between the block members adjacent to each other.
- the fan stream can be captured even during the operation of the thrust reverser.
- the heat exchange capacity of the pre-cooler can be thereby secured.
- a destination facility where the engine bleed air is used such as a cabin air-conditioner, while sufficiently cooling the engine bleed air.
- the pre-cooler may include an exhaust port that opens in a direction crossing the fan stream, and a projecting portion that projects in a direction crossing the fan stream on a front side of a peripheral edge of the exhaust port.
- the fan stream is turned in a direction away from the exhaust port before the projecting portion.
- the pressure of the fan stream is thereby increased to generate the effect of reducing a back pressure of the outlet of the exhaust port. Therefore, air is sucked out from the exhaust port, and smoothly discharged.
- the pre-cooler may include an exhaust port that opens in a direction crossing the fan stream, and a louver having a plurality of fins longitudinally arranged in the exhaust port.
- the louver contributes to smooth exhaust.
- the heat exchange capacity of each of the engine oil cooler and the pre-cooler can be secured even when there is a limitation to the installation space for accessories.
- the fuel consumption can be also improved.
- FIG. 1 is a schematic view illustrating a typical cross section of a turbofan engine and a nacelle of an aircraft according to an embodiment of the present invention
- FIG. 2 is a perspective view illustrating the appearance of the turbofan engine
- FIG. 3 is a sectional view taken along a line III-III in FIG. 1 ;
- FIG. 4 is a schematic view illustrating an engine oil cooler and a pre-cooler from above;
- FIGS. 5A and 5B show an exhaust port of the pre-cooler: FIG. 5A is a perspective view illustrating a view from a line V in FIG. 3 ; and FIG. 5B is a sectional schematic view; and
- FIG. 6 is a view illustrating a state in which a portion of a bypass flow path is blocked by blocker doors constituting a thrust reverser.
- an aircraft of the embodiment of the present invention includes a turbofan engine 10 .
- the turbofan engine 10 is supported on the lower side of a main wing 11 via a pylon 20 .
- turbofan engine 10 is a geared turbofan engine including a gear mechanism in the present embodiment, the turbofan engine 10 may be also a general turbofan engine not including a gear mechanism.
- the turbofan engine 10 includes an engine body 12 , a fan 13 , a nacelle 14 that constitutes an outer shell of the turbofan engine 10 , and a core cowl 15 that is provided on the inner side of the nacelle 14 .
- a side where the fan 13 is arranged is defined as a “front”, and a side opposite thereto is defined as a “back” in the turbofan engine 10 .
- a “circumferential direction” is the circumferential direction of the nacelle 14 .
- the circumferential direction of the nacelle 14 corresponds to the circumferential directions of the core cowl 15 , the engine body 12 , and the fan 13 .
- the engine body 12 includes a low-pressure compressor, a high-pressure compressor, a reduction gear mechanism that connects respective shafts of the low-pressure compressor and the high-pressure compressor, a combustion chamber, a high-pressure turbine, and a low-pressure turbine although the constituent elements are not shown in the drawings.
- the constituent elements are accommodated in an engine case 121 (i.e., the core cowl 15 ).
- a jet stream formed by the engine body 12 is ejected from an exhaust nozzle 122 .
- the engine body 12 is equipped with various accessories, such as a fuel control unit, a fuel pump, an igniter, and a plurality of heat exchangers.
- accessory machinery The accessories and pipes or the like associated with the accessories (hereinafter, referred to as accessory machinery) are densely installed around the engine body 12 and the fan 13 , or in engine access spaces S 1 and S 2 ( FIG. 3 ) described below within the nacelle 14 .
- the fan 13 is arranged anterior to the engine body 12 , and rotated when the torque of the high-pressure turbine or the low-pressure turbine of the engine body 12 is transmitted thereto.
- the fan 13 includes a fan body having a plurality of blades 131 ( FIG. 2 ), and a fan case 132 .
- the nacelle 14 includes an air inlet 16 that is located on a front end, and a cowl 17 that is contiguous to the air inlet 16 as shown in FIG. 2 .
- the upper limit of the diameter of the nacelle 14 is determined since it is necessary to ensure a height equal to or higher than a specified height between a lower portion of the nacelle 14 and the ground, and it is difficult to increase the length of a main landing gear in order to avoid a weight increase.
- the cowl 17 includes a first cowl 171 and a movable second cowl 172 .
- the first cowl 171 surrounds the fan 13 .
- the second cowl 172 is normally contiguous to the back side of the first cowl 171 , and is slid backward when a thrust reverser is operated.
- the second cowl 172 surrounds the core cowl 15 .
- the core cowl 15 surrounds the engine case 121 on the back side of the fan 13 as shown in FIG. 1 .
- Engine compartment ventilation and a fireproof compartment are produced by the core cowl 15 .
- the fan stream further traveling backward from the bypass flow path 18 , and the ventilation flow of the engine compartment ejected from the exhaust nozzle 122 join together, and is discharged backward from the turbofan engine 10 .
- All of the first and second cowls 171 and 172 and the core cowl 15 described above have a form in which the cowl is divided along a longitudinal direction at an upper portion (a twelve o'clock position) and a lower portion (a six o'clock position).
- the second cowl 172 includes a right side portion 172 R and a left side portion 172 L as shown in FIG. 3 .
- the right side portion 172 R and the left side portion 172 L are supported on a pylon body 21 by a hinge portion (not shown) that is provided at the twelve o'clock position.
- the right side portion 172 R and the left side portion 172 L are rotated to the outer side about the hinge portion at the time of maintenance.
- a right side portion 15 R and a left side portion 15 L of the core cowl 15 , and a right side portion and a left side portion (not shown) of the first cowl 171 are also similarly configured.
- the engine access space S 1 for installing the accessory machinery is prepared in a gap where the right side portion and the left side portion each having an arc shape in section face each other on the twelve o'clock side.
- the engine access space S 2 for installing the accessory machinery is prepared in a gap where the right side portion and the left side portion face each other on the six o'clock side.
- the engine access space S 1 is formed between the pylon body 21 and the engine body 12 .
- the engine access space S 2 is formed between the nacelle 14 and the engine body 12 .
- an upper portion (the twelve o'clock position) of the bypass flow path 18 is used as the engine access space S 1 .
- a lower portion (the six o'clock position) of the bypass flow path 18 is used as the engine access space S 2 for installing the accessory machinery.
- the engine access space S 1 is formed continuously or intermittently from the front end to the back end of the core cowl 15 .
- the diameter of the engine body 12 with respect to the diameter of the nacelle 14 is larger than that of a typical case.
- a distance between the outer periphery of the core cowl 15 and the inner periphery of the second cowl 172 is small. Therefore, the bypass flow path 18 also used as the engine access spaces S 1 and S 2 has a small radial dimension.
- the circumferential widths of the engine access spaces S 1 and S 2 are set to be small in order to ensure a flow path sectional area of the bypass flow path 18 and thereby obtain required thrust.
- the engine access spaces S 1 and S 2 do not have a volume large enough to arrange the accessory machinery therein with a margin.
- an installation space for the accessory machinery is limited due to the small distance between the core cowl 15 and the second cowl 172 .
- a width W 2 in a center portion is larger than a width W 1 on the both ends of a front side F and a back side B similarly to the nacelle 14 .
- a height (a dimension in a direction perpendicular to the paper plane in FIG. 4 ) in the longitudinal center portion is also higher than a height on the front and back ends. This is because the engine body 12 is reduced in diameter as shown in FIG. 1 .
- the engine access spaces S 1 and S 2 have a volume barely large enough to install the accessories in the center portion and a surrounding region thereof.
- an engine oil cooler 30 and a pre-cooler 40 are installed by use of the center portion of the engine access space S 1 that is expanded with respect to the front and back ends.
- the pylon 20 includes the pylon body 21 that is a structural member, and an aerodynamic cover 22 (a pylon fairing) that covers the pylon body 21 as shown in FIG. 1 .
- the pylon body 21 is formed in a box-like shape having a rectangular shape in section, and extends in the longitudinal direction.
- Respective pipes, wires or the like of a fuel system, a hydraulic system, and an electrical system are accommodated in the pylon body 21 .
- the pylon body 21 is also shaped so as to be expanded in a center portion with respect to front and back ends similarly to the engine access space S 1 .
- a lower portion of the pylon body 21 faces the engine access space S 1 as shown in FIG. 3 .
- the width of the pylon body 21 is also set to be small so as not to disturb the fan stream flowing around the engine access space S 1 .
- the large accessories such as the engine oil cooler 30 and the pre-cooler 40 are preferably accommodated in the pylon body, there is not enough space to accommodate the accessories in the pylon body 21 of the present embodiment due to the small width.
- the engine oil cooler 30 and the pre-cooler 40 are suspended from the lower portion of the pylon body 21 , and thereby supported as shown in FIG. 1 .
- the engine oil cooler 30 air oil cooler or fuel oil cooler
- the pre-cooler 40 supported by the pylon body 21 and arranged in the engine access space S 1 are described by reference to FIG. 4 .
- the engine oil cooler 30 and the pre-cooler 40 are arranged longitudinally close to each other in the engine access space S 1 between the pylon body 21 and the engine body 12 due to the limitation on the installation space.
- the engine oil cooler 30 is a heat exchanger that cools engine oil used in the engine body 12 for lubricating a sliding section or the like by using the fan stream as a heat source (a low-temperature source).
- the engine oil cooler 30 since the reduction gear mechanism slides at high speed to thereby generate heat, the engine oil tends to have a high temperature. Therefore, a large engine oil cooler having a high heat exchange capacity as compared to a case in which the engine oil cooler is mounted to a general turbofan engine not including the reduction gear mechanism is employed as the engine oil cooler 30 .
- the engine body 12 may operate unstably or stop operating.
- the operating life of an engine high-temperature component (a turbine bearing or the like) may be also reduced. Therefore, it is important to sufficiently exert the heat exchange capacity of the engine oil cooler 30 .
- the fan stream needs to be sufficiently introduced into the engine oil cooler 30 .
- the engine oil cooler 30 includes a body 31 having a heat exchange capacity, an AOC intake duct 32 , and an AOC exhaust duct 33 .
- the body 31 is of plate fin type where plate-like tubes and corrugate fins are laminated, and is formed in a rectangular parallelepiped shape.
- a heat exchanger such as a fin and tube type
- a body 41 of the pre-cooler 40 may be also applied to the body 31 .
- a body 41 of the pre-cooler 40 may be also applied to the body 31 .
- the body 31 is arranged perpendicular to or substantially perpendicular to the fan stream flowing from the front to the back so as to efficiently receive the fan stream.
- a lead-in pipe 311 for leading the engine oil from the engine body 12 into the plate tube is connected to a lower portion of the body 31 .
- a lead-out pipe (not shown) for returning the engine oil from inside the plate tube to the engine body 12 is also connected to the body 31 .
- the AOC intake duct 32 is connected to the front side of the body 31 , and opens in the front end of the engine access space S 1 .
- An intake port 320 of the AOC intake duct 32 is located at the origin of the fan stream, and directed forward. The air output from the fan 13 directly flows into the intake port 320 . Thus, the fan stream is sufficiently introduced into the engine oil cooler 30 .
- the AOC exhaust duct 33 is connected to the back side of the body 31 , and opens on one widthwise end side (here, the right side) of the engine access space S 1 .
- An exhaust port 330 of the AOC exhaust duct 33 is directed diagonally backward.
- Heat exchange is performed between the fan stream sucked by the AOC intake duct 32 , and discharged from the AOC exhaust duct 33 through the body 31 , and the engine oil flowing through the plate tube of the body 31 .
- the entire length of the ducts 32 and 33 needs to be short, and it is necessary to form a smooth continuous flow path from the introduction to the discharge of the fan stream in the ducts 32 and 33 .
- the pre-cooler 40 is a heat exchanger that cools bleed air from the engine body 12 by using the fan stream as a heat source.
- the bleed air from the engine body 12 is obtained by extracting a portion of air compressed within the engine body 12 . Although its temperature and pressure vary depending on whether the bleed air is extracted downstream of the low-pressure compressor or downstream of the high-pressure compressor, the bleed air has a high temperature and pressure in any case.
- the engine bleed air is cooled to a temperature at which the bleed air can be used for the air-conditioner or the like by the pre-cooler 40 that is arranged upstream of a destination where the engine bleed air is used.
- Examples of the destination where the engine bleed air is used include an air-conditioner in a cabin, and various anti-ice systems.
- the engine bleed air cooled by the pre-cooler 40 is also used for pressurizing the inside of the aircraft.
- the pre-cooler 40 includes the body 41 having a heat exchange capacity, the PC intake duct 42 , and the PC exhaust duct 43 .
- the body 41 is of plate fin type similarly to the body 31 of the engine oil cooler 30 .
- the body 41 is arranged posterior to the body 31 of the engine oil cooler 30 .
- the body 41 is arranged diagonally with respect to the fan stream so as to avoid interference with the body 31 and the exhaust duct 33 of the engine oil cooler 30 .
- a lead-in pipe 411 for leading the engine bleed air from the engine body 12 into the plate tube of the body 41 is connected to a lower portion of the body 41 .
- a lead-out pipe (not shown) for sending the cooled engine bleed air from inside the plate tube to the destination of use is also connected to the body 41 .
- the PC intake duct 42 is connected to the front side of the body 41 , and opens on the left side of the engine access space S 1 .
- An intake port 420 of the PC intake duct 42 is directed diagonally forward.
- the intake port 420 is located on the opposite side from the exhaust port 330 of the AOC exhaust duct 33 . This is because the cooling efficiency of the pre-cooler 40 is reduced when the air discharged from the exhaust port 330 of the engine oil cooler 30 is sucked from the intake port 420 .
- a so-called NACA scoop (an NACA duct) can be employed for the PC intake duct 42 .
- the NACA scoop is formed so as to have a small inlet, and gradually expand from the inlet to the downstream side. Since the NACA scoop has extremely small air resistance, the fan stream can be efficiently introduced.
- the PC exhaust duct 43 is connected to the back side of the body 41 , and opens on the same side (the right side) as the opening of the AOC exhaust duct 33 .
- An exhaust port 430 of the PC exhaust duct 43 is directed diagonally backward, and located posterior to the intake port 420 .
- the exhaust port 430 is formed in the aerodynamic cover 22 on the outer side of the engine access space S 1 .
- the intake port 320 and the exhaust port 330 of the engine oil cooler 30 , and the intake port 420 of the pre-cooler 40 can be also formed in the aerodynamic cover 22 that covers the pylon body 21 .
- Heat exchange is performed between the fan stream sucked by the PC intake duct 42 , and discharged from the PC exhaust duct 43 through the body 41 , and the engine bleed air flowing through the plate tube of the body 41 .
- the PC exhaust duct 43 includes the exhaust port 430 having a rectangular shape here, a tab plate 44 (a projecting portion) that is located on a peripheral edge 431 of the exhaust port 430 , and a louver 45 that is located in the exhaust port 430 .
- FIGS. 5A and 5B the front side is indicated by F and the back side is indicated by B.
- the exhaust port 430 is located in a side surface 22 A of the aerodynamic cover 22 of the pylon 20 .
- the exhaust port 330 of the engine oil cooler 30 is also located in the side surface 22 A of the aerodynamic cover 22 on the front side F with respect to the exhaust port 430 .
- the tab plate 44 is formed so as to project from the side surface 22 A on the peripheral edge 431 of the exhaust port 430 .
- the tab plate 44 has a front-side tab 441 located on the front side F of the peripheral edge 431 , and a lower-side tab 442 located on the lower side of the peripheral edge 431 .
- the front-side tab 441 is formed in a band-like shape along the front side F of the peripheral edge 431 . As shown in FIG. 5B , a distal end 441 B of the front-side tab 441 is located posterior to a proximal end 441 A of the front-side tab 441 that is contiguous to the side surface 22 A. That is, the front-side tab 441 diagonally stands from the side surface 22 A.
- the lower-side tab 442 is formed in a band-like shape along the lower side of the peripheral edge 431 .
- the lower-side tab 442 vertically stands from the side surface 22 A.
- the lower end of the front-side tab 441 and the front end of the lower-side tab 442 are contiguous to each other. Accordingly, the exhaust port 430 is surrounded from two directions of the front side F and the lower side.
- the louver 45 has a plurality of fins 451 that are arranged in the longitudinal direction.
- the fins 451 are inclined in the same direction as the front-side tab 441 , and backwardly adjust the flow of the air discharged from the exhaust port 430 .
- the exhaust port 330 of the engine oil cooler 30 is located on the front side F with respect to the exhaust port 430 .
- the air heat-exchanged with the engine oil is ejected from the exhaust port 330 toward the exhaust port 430 .
- the air joins the fan stream flowing along the side surface 22 A of the aerodynamic cover 22 from the bypass flow path 18 .
- the tab plate 44 described above works to prevent the air ejected from the exhaust port 330 of the engine oil cooler 30 as described above and the fan stream from disturbing the exhaust air from the exhaust port 430 .
- the front-side tab 441 of the tab plate 44 projects in a direction crossing the fan stream on the front side F of the peripheral edge 431 of the exhaust port 430 . Therefore, the fan stream is turned in a direction away from the exhaust port 430 as indicated by arrows in FIG. 5B before the tab plate 44 . The pressure of the fan stream is thereby increased to generate the effect of reducing an outlet pressure (a back pressure) of a front surface of the exhaust port 430 . Accordingly, the air is sucked out from the exhaust port 430 , and smoothly discharged.
- louver 45 The air whose flow is adjusted by the louver 45 smoothly joins the fan stream. Thus, the air stream around the exhaust port 430 is not disturbed. In this point, the louver 45 contributes to the smooth exhaust.
- the exhaust air from the pre-cooler 40 is not disturbed by the exhaust air from the engine oil cooler 30 and the fan stream, so that the fan stream is stably introduced into and discharged from the pre-cooler 40 . Accordingly, the engine bleed air sufficiently cooled by using the fan stream as the heat source can be stably supplied to the destination of use.
- the front-side tab 441 projects perpendicular to the fan stream, or is inclined such that the proximal end 441 A is located posterior to the distal end 441 B, the air is sucked out from the exhaust port 430 by the same action as above.
- a swirling air stream is easily generated around the exhaust port 430 . The effect of sucking out the air may be reduced by the swirl.
- the front-side tab 441 is preferably inclined such that the distal end 441 B is located posterior to the proximal end 441 A ( FIG. 5B ).
- the exhaust port 430 is surrounded by the front-side tab 441 and the lower-side tab 442 , the exhaust air from the engine oil cooler 30 is prevented from entering the exhaust port 430 to decrease a flow rate in the pre-cooler 40 . That is, an intake/exhaust amount meeting cooling performance required for the pre-cooler 40 can be ensured.
- the exhaust port 430 of the present embodiment opens in a direction crossing the fan stream
- the exhaust port of the pre-cooler 40 may also open along the fan stream.
- the engine oil cooler 30 and the pre-cooler 40 are longitudinally arranged in the engine access space S 1 ( FIG. 4 ), and thereby arranged in one position (here, an upper portion) in the circumferential direction in a concentrated manner. Accordingly, a region where the engine oil cooler 30 and the pre-cooler 40 work as resistance to block the fan stream is limited to the one position in the circumferential direction.
- the fan stream is blocked by the engine oil cooler 30 , and also blocked by the pre-cooler 40 .
- the engine oil cooler 30 is arranged behind the fan 13 , and the pre-cooler 40 is arranged posterior to the engine oil cooler 30 in consideration of the importance of the engine oil cooler 30 .
- the fan stream can be directly introduced into the engine oil cooler 30 from the fan 13 .
- the heat exchange capacity of the engine oil cooler 30 can be thereby fully exerted.
- the pre-cooler 40 introduces the fan stream therein via the PC intake duct 42 that opens diagonally forward by avoiding interference with the body 31 and the exhaust duct 33 of the engine oil cooler 30 that is arranged anterior to the pre-cooler 40 .
- This is disadvantageous in introducing the fan stream since a pressure loss is larger than that of a case in which the fan stream is introduced from the front as in the engine oil cooler 30 .
- the fan stream can be introduced sufficiently enough to secure the heat exchange capacity of the pre-cooler 40 by appropriately designing the positions, forms or the like of the intake port 420 , the exhaust port 430 , and the ducts 42 and 43 of the pre-cooler 40 .
- the heat exchange capacity of each of the engine oil cooler 30 and the pre-cooler 40 can be secured under the limitation on the installation space for the accessory machinery, and the fuel consumption can be also improved.
- the circumferential position (region) where the engine oil cooler 30 and the pre-cooler 40 are arranged is not limited to the upper portion, and may be also a lower portion or other positions.
- the aircraft includes a thrust reverser that generates a portion of thrust toward the front side.
- the thrust reverser assists braking when an overrun is likely to be caused by using only other braking mechanisms such as a wheel brake of a main landing gear.
- the thrust reverser of the turbofan engine 10 includes a blocker door 19 ( FIG. 6 ) that blocks passage of the fan stream, and reverses the fan stream to the front side, and an air discharge section (not shown) that discharges the fan stream blocked by the blocker door 19 to the diagonally front side.
- the air discharge section is located in a gap formed between the first cowl 171 and the second cowl 172 when the second cowl 172 is slid backward.
- a plurality of blocker doors 19 are arranged in the bypass flow path 18 at intervals in a circumferential direction.
- the blocker doors 19 are attached to the inner side of the second cowl 172 by hinges so as to be able to be changed in position between a position along the inner periphery of the second cowl 172 and a position erected from the inner periphery of the second cowl 172 ( FIG. 6 ).
- each of the blocker doors 19 When the thrust reverser is operated, each of the blocker doors 19 is erected, and a portion of the bypass flow path 18 is blocked by each of the blocker doors 19 . The fan stream flowing backward from the blocker doors 19 is thereby reduced.
- the intake ports 320 and 420 of the engine oil cooler 30 and the pre-cooler 40 are preferably located anterior to the blocker doors 19 . Accordingly, the fan stream is ensured around the intake ports 320 and 420 even during the operation of the thrust reverser, so that the heat exchange capacity can be secured by introducing the fan stream from the intake ports 320 and 420 .
- the intake port 320 of the engine oil cooler 30 is located anterior to the blocker doors 19
- a part of the intake port 420 of the pre-cooler 40 is located posterior to the blocker doors 19 as a result of avoiding interference with the engine oil cooler 30 and the other accessory machinery.
- the intake port 420 of the pre-cooler 40 is preferably arranged behind (at the back of) a gap between the blocker door 19 and the blocker door 19 adjacent to each other.
- the fan stream passing through the gap between the adjacent blocker doors 19 and 19 can be captured by the intake port 420 .
- the heat exchange capacity of the pre-cooler 40 can be secured even during the operation of the thrust reverser.
- the engine oil cooler 30 and the pre-cooler 40 are longitudinally arranged on the outer side of the pylon body 21 in the above embodiment, the engine oil cooler and the pre-cooler may be also longitudinally arranged on the inner side of the pylon body in the present invention.
- the engine oil cooler and the pre-cooler are arranged in one position in the circumferential direction in a concentrated manner even within the pylon body, a decrease in thrust due to the blockage of the fan stream can be also suppressed.
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Abstract
Description
- 1. Field of the Invention
- The present invention relates to an aircraft including a turbofan engine, and more particularly, to arrangement of an engine oil cooler and a pre-cooler.
- 2. Description of the Related Art
- A turbofan engine of an aircraft includes a fan that is rotated by power produced by the engine. When the turbofan engine is operated, air is distributed into an engine body and a bypass flow path formed on the inner side of a nacelle. Air passing through the bypass flow path and air discharged from a nozzle of the engine body join together to be ejected backward. Thrust is obtained by the reaction of the jet stream.
- Generally, the engine is equipped with various accessories, such as a fuel control unit, a fuel pump, an igniter, and a plurality of heat exchangers. The accessories are provided around, above and below the engine and the fan within the nacelle.
- Examples of the accessories include a pre-cooler that cools bleed air from the engine so as to use the bleed air for a cabin air-conditioner or the like (Japanese Patent No. 4805352), and an engine oil cooler that cools engine oil.
- Both the engine oil cooler and the pre-cooler are heat exchangers that use the air flowing through the bypass flow path (hereinafter, referred to as a fan stream) as a heat source (a low-temperature source) in the turbofan engine. The fan stream is sucked therein from the bypass flow path, and exhausted after heat exchange with the engine oil and the engine bleed air.
- In order to sufficiently exert a heat exchange capacity, the engine oil cooler and the pre-cooler mounted to the turbofan engine are preferably provided at positions where the fan stream can be sufficiently introduced.
- For example, it is assumed that the pre-cooler is provided in an upper portion within the bypass flow path of the engine body. In this case, the engine oil cooler is preferably arranged at a circumferentially different position from the pre-cooler, such as a position lateral to the engine body, so as to sufficiently introduce the fan stream therein without being disturbed by the pre-cooler.
- However, in many cases, the engine oil cooler or the pre-cooler cannot be provided at a favorable position since its installation space is limited due to interference with another accessory or the like. Particularly, in medium and small aircrafts having a smaller engine size than that of a large aircraft, the accessories are concentrated around the engine body. Thus, the installation space is greatly limited.
- When the fan stream is blocked by the engine oil cooler and the pre-cooler, smaller thrust is obtained, and fuel consumption is deteriorated.
- Here, if the diameter of the nacelle is increased with respect to the diameter of the engine body, a required flow rate can be ensured. However, since it is necessary to ensure a height equal to or larger than a specified height between the nacelle and the ground, the diameter of the nacelle may not be enlarged in some cases. The nacelle diameter can be enlarged by increasing the length of a main landing gear. However, a weight increase is caused, and the fuel consumption is deteriorated.
- Based on the above problems, an object of the present invention is to provide an aircraft including a turbofan engine which can secure a heat exchange capacity of each of an engine oil cooler and a pre-cooler while avoiding a deterioration in fuel consumption even when an accessory installation space is limited.
- An aircraft of the present invention is an aircraft including a turbofan engine provided with an engine body and a fan located anterior to the engine body, further including: an engine oil cooler that is a heat exchanger for cooling engine oil used in the engine body by using, as a heat source, a fan stream flowing from the fan into a gap between a core cowl surrounding the engine body and a nacelle surrounding the fan and the core cowl; and a pre-cooler that is a heat exchanger for cooling bleed air from the engine body by using the fan stream as a heat source.
- In the present invention, the engine oil cooler and the pre-cooler are longitudinally arranged in one position (one region) in a circumferential direction of the nacelle, and the engine oil cooler is located anterior to the pre-cooler.
- In the present invention, the engine oil cooler and the pre-cooler are arranged in the one position in the circumferential direction in a concentrated manner. Thus, a region where the engine oil cooler and the pre-cooler work as resistance to block the fan stream is limited to the one position in the circumferential direction.
- Therefore, as compared to a case in which the engine oil cooler and the pre-cooler are arranged at circumferentially different positions, a decrease in thrust due to the blockage of the fan stream can be suppressed. Fuel consumption can be thereby improved.
- Moreover, in the present invention, the engine oil cooler having higher importance for surely operating the engine body is arranged anterior to the pre-cooler, and the pre-cooler is arranged posterior to the engine oil cooler.
- Accordingly, the fan stream can be sufficiently introduced into the engine oil cooler from the front regardless of the existence of the pre-cooler.
- However, if the pre-cooler and the engine oil cooler are located close to each other due to a small installation space, the engine oil cooler works as resistance against the fan stream for the pre-cooler that is arranged posterior to the engine oil cooler. Moreover, since the pre-cooler introduces the fan stream from the diagonally front by avoiding interference with the engine oil cooler that is arranged anterior to the pre-cooler, it is difficult to introduce the fan stream into the pre-cooler from the front. Introducing the fan stream into the pre-cooler from the diagonally front is disadvantageous in introducing the fan stream since a pressure loss is larger than that of a case in which the fan stream is introduced from the front.
- However, the fan stream can be introduced sufficiently enough to secure the heat exchange capacity of the pre-cooler by appropriately designing the positions, forms or the like of an intake port, an exhaust port, and a duct of the pre-cooler.
- Even if the fan stream cannot be sufficiently introduced and the engine bleed air is insufficiently cooled to cause a failure in a destination facility where the bleed air is used (an air-conditioning unit or the like), the failure is not as serious as that of a case in which a failure occurs in the engine when the engine oil is insufficiently cooled, and can be treated by an airframe-side system.
- In accordance with the above configuration, by longitudinally arranging the engine oil cooler and the pre-cooler in the one position in the circumferential direction of the nacelle such that the engine oil cooler is arranged anterior to the pre-cooler, the heat exchange capacity of each of the engine oil cooler and the pre-cooler can be secured even when there is a limitation to an installation space for accessory machinery. The fuel consumption can be also improved.
- In the aircraft of the present invention, the engine oil cooler and the pre-cooler may be longitudinally arranged between a pylon that supports the turbofan engine on a main wing, and the engine body.
- The nacelle and the core cowl are each divided into right and left portions. In this case, the engine oil cooler and the pre-cooler can be arranged in an engine access space that is prepared in a gap where left side portions and right side portions of the nacelle and the core cowl face each other on the upper side where a hinge is located.
- The engine oil cooler and the pre-cooler may be supported on the pylon.
- In the aircraft of the present invention, the engine oil cooler may introduce the fan stream from a front.
- Accordingly, the fan stream is allowed to smoothly flow into the engine oil cooler directly from the fan.
- In the aircraft of the present invention, a plurality of block members that block passage of the fan stream when a thrust reverser that generates a portion of thrust to a front side is operated may be arranged at intervals in a circumferential direction, and the pre-cooler may introduce the fan stream passing through a gap between the block members adjacent to each other.
- Accordingly, the fan stream can be captured even during the operation of the thrust reverser. The heat exchange capacity of the pre-cooler can be thereby secured. Thus, it is possible to operate a destination facility where the engine bleed air is used, such as a cabin air-conditioner, while sufficiently cooling the engine bleed air.
- In the aircraft of the present invention, the pre-cooler may include an exhaust port that opens in a direction crossing the fan stream, and a projecting portion that projects in a direction crossing the fan stream on a front side of a peripheral edge of the exhaust port.
- Accordingly, the fan stream is turned in a direction away from the exhaust port before the projecting portion. The pressure of the fan stream is thereby increased to generate the effect of reducing a back pressure of the outlet of the exhaust port. Therefore, air is sucked out from the exhaust port, and smoothly discharged.
- Consequently, exhaust air from the pre-cooler is not disturbed by exhaust air from the engine oil cooler that is arranged anterior to the pre-cooler and the fan stream, so that the fan stream is stably introduced into and discharged from the pre-cooler. The engine bleed air sufficiently cooled by using the fan stream as the heat source can be thereby stably supplied to the destination of use.
- In the turbofan engine of the aircraft of the present invention, the pre-cooler may include an exhaust port that opens in a direction crossing the fan stream, and a louver having a plurality of fins longitudinally arranged in the exhaust port.
- Accordingly, the air whose flow is adjusted by the louver smoothly joins the fan stream. Thus, the air stream around the exhaust port is not disturbed. In this point, the louver contributes to smooth exhaust.
- In accordance with the present invention, the heat exchange capacity of each of the engine oil cooler and the pre-cooler can be secured even when there is a limitation to the installation space for accessories. The fuel consumption can be also improved.
-
FIG. 1 is a schematic view illustrating a typical cross section of a turbofan engine and a nacelle of an aircraft according to an embodiment of the present invention; -
FIG. 2 is a perspective view illustrating the appearance of the turbofan engine; -
FIG. 3 is a sectional view taken along a line III-III inFIG. 1 ; -
FIG. 4 is a schematic view illustrating an engine oil cooler and a pre-cooler from above; -
FIGS. 5A and 5B show an exhaust port of the pre-cooler:FIG. 5A is a perspective view illustrating a view from a line V inFIG. 3 ; andFIG. 5B is a sectional schematic view; and -
FIG. 6 is a view illustrating a state in which a portion of a bypass flow path is blocked by blocker doors constituting a thrust reverser. - In the following, an embodiment of the present invention is described by reference to the accompanying drawings.
- As shown in
FIG. 1 , an aircraft of the embodiment of the present invention includes aturbofan engine 10. - The
turbofan engine 10 is supported on the lower side of amain wing 11 via apylon 20. - Although the
turbofan engine 10 is a geared turbofan engine including a gear mechanism in the present embodiment, theturbofan engine 10 may be also a general turbofan engine not including a gear mechanism. - The schematic configuration of the
turbofan engine 10 is described. - The
turbofan engine 10 includes anengine body 12, afan 13, anacelle 14 that constitutes an outer shell of theturbofan engine 10, and acore cowl 15 that is provided on the inner side of thenacelle 14. - In the present specification, a side where the
fan 13 is arranged is defined as a “front”, and a side opposite thereto is defined as a “back” in theturbofan engine 10. - Unless otherwise noted, a “circumferential direction” is the circumferential direction of the
nacelle 14. The circumferential direction of thenacelle 14 corresponds to the circumferential directions of thecore cowl 15, theengine body 12, and thefan 13. - The
engine body 12 includes a low-pressure compressor, a high-pressure compressor, a reduction gear mechanism that connects respective shafts of the low-pressure compressor and the high-pressure compressor, a combustion chamber, a high-pressure turbine, and a low-pressure turbine although the constituent elements are not shown in the drawings. The constituent elements are accommodated in an engine case 121 (i.e., the core cowl 15). A jet stream formed by theengine body 12 is ejected from anexhaust nozzle 122. - Although not shown in the drawings, the
engine body 12 is equipped with various accessories, such as a fuel control unit, a fuel pump, an igniter, and a plurality of heat exchangers. - The accessories and pipes or the like associated with the accessories (hereinafter, referred to as accessory machinery) are densely installed around the
engine body 12 and thefan 13, or in engine access spaces S1 and S2 (FIG. 3 ) described below within thenacelle 14. - The
fan 13 is arranged anterior to theengine body 12, and rotated when the torque of the high-pressure turbine or the low-pressure turbine of theengine body 12 is transmitted thereto. - The
fan 13 includes a fan body having a plurality of blades 131 (FIG. 2 ), and afan case 132. - The
nacelle 14 includes anair inlet 16 that is located on a front end, and acowl 17 that is contiguous to theair inlet 16 as shown inFIG. 2 . - The upper limit of the diameter of the
nacelle 14 is determined since it is necessary to ensure a height equal to or higher than a specified height between a lower portion of thenacelle 14 and the ground, and it is difficult to increase the length of a main landing gear in order to avoid a weight increase. - The
cowl 17 includes afirst cowl 171 and a movablesecond cowl 172. - The
first cowl 171 surrounds thefan 13. - The
second cowl 172 is normally contiguous to the back side of thefirst cowl 171, and is slid backward when a thrust reverser is operated. Thesecond cowl 172 surrounds thecore cowl 15. - The
core cowl 15 surrounds theengine case 121 on the back side of thefan 13 as shown inFIG. 1 . Engine compartment ventilation and a fireproof compartment are produced by thecore cowl 15. - When air introduced into the
nacelle 14 from theair inlet 16 is output backward by thefan 13, the air is divided into a flow supplied into theengine body 12 within the engine case 121 (ventilation of the inside of an engine compartment), and a flow passing through abypass flow path 18 between thecore cowl 15 and the second cowl 172 (a fan stream). - The fan stream further traveling backward from the
bypass flow path 18, and the ventilation flow of the engine compartment ejected from theexhaust nozzle 122 join together, and is discharged backward from theturbofan engine 10. - All of the first and
second cowls core cowl 15 described above have a form in which the cowl is divided along a longitudinal direction at an upper portion (a twelve o'clock position) and a lower portion (a six o'clock position). - For example, the
second cowl 172 includes aright side portion 172R and aleft side portion 172L as shown inFIG. 3 . Theright side portion 172R and theleft side portion 172L are supported on apylon body 21 by a hinge portion (not shown) that is provided at the twelve o'clock position. Theright side portion 172R and theleft side portion 172L are rotated to the outer side about the hinge portion at the time of maintenance. - A
right side portion 15R and aleft side portion 15L of thecore cowl 15, and a right side portion and a left side portion (not shown) of thefirst cowl 171 are also similarly configured. - The engine access space S1 for installing the accessory machinery is prepared in a gap where the right side portion and the left side portion each having an arc shape in section face each other on the twelve o'clock side. The engine access space S2 for installing the accessory machinery is prepared in a gap where the right side portion and the left side portion face each other on the six o'clock side.
- The engine access space S1 is formed between the
pylon body 21 and theengine body 12. - The engine access space S2 is formed between the
nacelle 14 and theengine body 12. - As shown in
FIG. 3 , an upper portion (the twelve o'clock position) of thebypass flow path 18 is used as the engine access space S1. A lower portion (the six o'clock position) of thebypass flow path 18 is used as the engine access space S2 for installing the accessory machinery. - The engine access space S1 is formed continuously or intermittently from the front end to the back end of the
core cowl 15. - In the present embodiment, the diameter of the
engine body 12 with respect to the diameter of thenacelle 14 is larger than that of a typical case. Thus, a distance between the outer periphery of thecore cowl 15 and the inner periphery of thesecond cowl 172 is small. Therefore, thebypass flow path 18 also used as the engine access spaces S1 and S2 has a small radial dimension. - Moreover, the circumferential widths of the engine access spaces S1 and S2 are set to be small in order to ensure a flow path sectional area of the
bypass flow path 18 and thereby obtain required thrust. - Thus, the engine access spaces S1 and S2 do not have a volume large enough to arrange the accessory machinery therein with a margin.
- That is, an installation space for the accessory machinery is limited due to the small distance between the
core cowl 15 and thesecond cowl 172. - As shown in
FIG. 4 , in the engine access spaces S1 and S2 (only S1 is shown), a width W2 in a center portion is larger than a width W1 on the both ends of a front side F and a back side B similarly to thenacelle 14. - In the engine access spaces S1 and S2, a height (a dimension in a direction perpendicular to the paper plane in
FIG. 4 ) in the longitudinal center portion is also higher than a height on the front and back ends. This is because theengine body 12 is reduced in diameter as shown inFIG. 1 . - That is, the engine access spaces S1 and S2 have a volume barely large enough to install the accessories in the center portion and a surrounding region thereof.
- In the present embodiment, an
engine oil cooler 30 and a pre-cooler 40 are installed by use of the center portion of the engine access space S1 that is expanded with respect to the front and back ends. - The
pylon 20 includes thepylon body 21 that is a structural member, and an aerodynamic cover 22 (a pylon fairing) that covers thepylon body 21 as shown inFIG. 1 . - The
pylon body 21 is formed in a box-like shape having a rectangular shape in section, and extends in the longitudinal direction. - Respective pipes, wires or the like of a fuel system, a hydraulic system, and an electrical system are accommodated in the
pylon body 21. Thepylon body 21 is also shaped so as to be expanded in a center portion with respect to front and back ends similarly to the engine access space S1. - A lower portion of the
pylon body 21 faces the engine access space S1 as shown inFIG. 3 . - The width of the
pylon body 21 is also set to be small so as not to disturb the fan stream flowing around the engine access space S1. - Although the large accessories such as the
engine oil cooler 30 and the pre-cooler 40 are preferably accommodated in the pylon body, there is not enough space to accommodate the accessories in thepylon body 21 of the present embodiment due to the small width. - In the present embodiment, the
engine oil cooler 30 and the pre-cooler 40 are suspended from the lower portion of thepylon body 21, and thereby supported as shown inFIG. 1 . - Now, the engine oil cooler 30 (air oil cooler or fuel oil cooler) and the pre-cooler 40 supported by the
pylon body 21 and arranged in the engine access space S1 are described by reference toFIG. 4 . - The
engine oil cooler 30 and the pre-cooler 40 are arranged longitudinally close to each other in the engine access space S1 between thepylon body 21 and theengine body 12 due to the limitation on the installation space. - The engine oil cooler 30 is a heat exchanger that cools engine oil used in the
engine body 12 for lubricating a sliding section or the like by using the fan stream as a heat source (a low-temperature source). - In the present embodiment, since the reduction gear mechanism slides at high speed to thereby generate heat, the engine oil tends to have a high temperature. Therefore, a large engine oil cooler having a high heat exchange capacity as compared to a case in which the engine oil cooler is mounted to a general turbofan engine not including the reduction gear mechanism is employed as the
engine oil cooler 30. - If the engine oil is not sufficiently cooled, the
engine body 12 may operate unstably or stop operating. The operating life of an engine high-temperature component (a turbine bearing or the like) may be also reduced. Therefore, it is important to sufficiently exert the heat exchange capacity of theengine oil cooler 30. - To this end, the fan stream needs to be sufficiently introduced into the
engine oil cooler 30. - The engine oil cooler 30 includes a body 31 having a heat exchange capacity, an
AOC intake duct 32, and anAOC exhaust duct 33. - The body 31 is of plate fin type where plate-like tubes and corrugate fins are laminated, and is formed in a rectangular parallelepiped shape.
- Various types known as a heat exchanger, such as a fin and tube type, may be also applied to the body 31. The same applies to a body 41 of the pre-cooler 40.
- The body 31 is arranged perpendicular to or substantially perpendicular to the fan stream flowing from the front to the back so as to efficiently receive the fan stream.
- A lead-in
pipe 311 for leading the engine oil from theengine body 12 into the plate tube is connected to a lower portion of the body 31. A lead-out pipe (not shown) for returning the engine oil from inside the plate tube to theengine body 12 is also connected to the body 31. - The
AOC intake duct 32 is connected to the front side of the body 31, and opens in the front end of the engine access space S1. Anintake port 320 of theAOC intake duct 32 is located at the origin of the fan stream, and directed forward. The air output from thefan 13 directly flows into theintake port 320. Thus, the fan stream is sufficiently introduced into theengine oil cooler 30. - The
AOC exhaust duct 33 is connected to the back side of the body 31, and opens on one widthwise end side (here, the right side) of the engine access space S1. Anexhaust port 330 of theAOC exhaust duct 33 is directed diagonally backward. - Heat exchange is performed between the fan stream sucked by the
AOC intake duct 32, and discharged from theAOC exhaust duct 33 through the body 31, and the engine oil flowing through the plate tube of the body 31. - In order to reduce a pressure loss, the entire length of the
ducts ducts ducts - It is also preferable to form a recess in a portion where interference with the other accessory machinery or the
engine case 121 needs to be avoided, in any of theducts ducts - Next, the pre-cooler 40 is a heat exchanger that cools bleed air from the
engine body 12 by using the fan stream as a heat source. - The bleed air from the
engine body 12 is obtained by extracting a portion of air compressed within theengine body 12. Although its temperature and pressure vary depending on whether the bleed air is extracted downstream of the low-pressure compressor or downstream of the high-pressure compressor, the bleed air has a high temperature and pressure in any case. - Since it is difficult to directly use the engine bleed air as a heat source in a cabin air-conditioner or the like, the engine bleed air is cooled to a temperature at which the bleed air can be used for the air-conditioner or the like by the pre-cooler 40 that is arranged upstream of a destination where the engine bleed air is used.
- Examples of the destination where the engine bleed air is used include an air-conditioner in a cabin, and various anti-ice systems.
- The engine bleed air cooled by the pre-cooler 40 is also used for pressurizing the inside of the aircraft.
- The pre-cooler 40 includes the body 41 having a heat exchange capacity, the
PC intake duct 42, and thePC exhaust duct 43. - The body 41 is of plate fin type similarly to the body 31 of the
engine oil cooler 30. - The body 41 is arranged posterior to the body 31 of the
engine oil cooler 30. The body 41 is arranged diagonally with respect to the fan stream so as to avoid interference with the body 31 and theexhaust duct 33 of theengine oil cooler 30. - A lead-in
pipe 411 for leading the engine bleed air from theengine body 12 into the plate tube of the body 41 is connected to a lower portion of the body 41. A lead-out pipe (not shown) for sending the cooled engine bleed air from inside the plate tube to the destination of use is also connected to the body 41. - The
PC intake duct 42 is connected to the front side of the body 41, and opens on the left side of the engine access space S1. Anintake port 420 of thePC intake duct 42 is directed diagonally forward. - The
intake port 420 is located on the opposite side from theexhaust port 330 of theAOC exhaust duct 33. This is because the cooling efficiency of the pre-cooler 40 is reduced when the air discharged from theexhaust port 330 of the engine oil cooler 30 is sucked from theintake port 420. - A so-called NACA scoop (an NACA duct) can be employed for the
PC intake duct 42. The NACA scoop is formed so as to have a small inlet, and gradually expand from the inlet to the downstream side. Since the NACA scoop has extremely small air resistance, the fan stream can be efficiently introduced. - The
PC exhaust duct 43 is connected to the back side of the body 41, and opens on the same side (the right side) as the opening of theAOC exhaust duct 33. Anexhaust port 430 of thePC exhaust duct 43 is directed diagonally backward, and located posterior to theintake port 420. Theexhaust port 430 is formed in theaerodynamic cover 22 on the outer side of the engine access space S1. Theintake port 320 and theexhaust port 330 of theengine oil cooler 30, and theintake port 420 of the pre-cooler 40 can be also formed in theaerodynamic cover 22 that covers thepylon body 21. - Heat exchange is performed between the fan stream sucked by the
PC intake duct 42, and discharged from thePC exhaust duct 43 through the body 41, and the engine bleed air flowing through the plate tube of the body 41. - A specific configuration for enabling smooth exhaust from the
PC exhaust duct 43 is described. - As shown in
FIG. 5A , thePC exhaust duct 43 includes theexhaust port 430 having a rectangular shape here, a tab plate 44 (a projecting portion) that is located on aperipheral edge 431 of theexhaust port 430, and alouver 45 that is located in theexhaust port 430. - In
FIGS. 5A and 5B , the front side is indicated by F and the back side is indicated by B. - The
exhaust port 430 is located in aside surface 22A of theaerodynamic cover 22 of thepylon 20. - The
exhaust port 330 of the engine oil cooler 30 is also located in theside surface 22A of theaerodynamic cover 22 on the front side F with respect to theexhaust port 430. - The
tab plate 44 is formed so as to project from theside surface 22A on theperipheral edge 431 of theexhaust port 430. - The
tab plate 44 has a front-side tab 441 located on the front side F of theperipheral edge 431, and a lower-side tab 442 located on the lower side of theperipheral edge 431. - The front-
side tab 441 is formed in a band-like shape along the front side F of theperipheral edge 431. As shown inFIG. 5B , adistal end 441B of the front-side tab 441 is located posterior to aproximal end 441A of the front-side tab 441 that is contiguous to theside surface 22A. That is, the front-side tab 441 diagonally stands from theside surface 22A. - The lower-
side tab 442 is formed in a band-like shape along the lower side of theperipheral edge 431. The lower-side tab 442 vertically stands from theside surface 22A. - The lower end of the front-
side tab 441 and the front end of the lower-side tab 442 are contiguous to each other. Accordingly, theexhaust port 430 is surrounded from two directions of the front side F and the lower side. - The
louver 45 has a plurality offins 451 that are arranged in the longitudinal direction. - The
fins 451 are inclined in the same direction as the front-side tab 441, and backwardly adjust the flow of the air discharged from theexhaust port 430. - As described above, the
exhaust port 330 of the engine oil cooler 30 is located on the front side F with respect to theexhaust port 430. The air heat-exchanged with the engine oil is ejected from theexhaust port 330 toward theexhaust port 430. The air joins the fan stream flowing along theside surface 22A of theaerodynamic cover 22 from thebypass flow path 18. - The
tab plate 44 described above works to prevent the air ejected from theexhaust port 330 of the engine oil cooler 30 as described above and the fan stream from disturbing the exhaust air from theexhaust port 430. - The front-
side tab 441 of thetab plate 44 projects in a direction crossing the fan stream on the front side F of theperipheral edge 431 of theexhaust port 430. Therefore, the fan stream is turned in a direction away from theexhaust port 430 as indicated by arrows inFIG. 5B before thetab plate 44. The pressure of the fan stream is thereby increased to generate the effect of reducing an outlet pressure (a back pressure) of a front surface of theexhaust port 430. Accordingly, the air is sucked out from theexhaust port 430, and smoothly discharged. - The air whose flow is adjusted by the
louver 45 smoothly joins the fan stream. Thus, the air stream around theexhaust port 430 is not disturbed. In this point, thelouver 45 contributes to the smooth exhaust. - As described above, mainly by providing the front-
side tab 441, the exhaust air from the pre-cooler 40 is not disturbed by the exhaust air from theengine oil cooler 30 and the fan stream, so that the fan stream is stably introduced into and discharged from the pre-cooler 40. Accordingly, the engine bleed air sufficiently cooled by using the fan stream as the heat source can be stably supplied to the destination of use. - If the front-
side tab 441 projects perpendicular to the fan stream, or is inclined such that theproximal end 441A is located posterior to thedistal end 441B, the air is sucked out from theexhaust port 430 by the same action as above. However, a swirling air stream is easily generated around theexhaust port 430. The effect of sucking out the air may be reduced by the swirl. Thus, the front-side tab 441 is preferably inclined such that thedistal end 441B is located posterior to theproximal end 441A (FIG. 5B ). - Since the
exhaust port 430 is surrounded by the front-side tab 441 and the lower-side tab 442, the exhaust air from the engine oil cooler 30 is prevented from entering theexhaust port 430 to decrease a flow rate in the pre-cooler 40. That is, an intake/exhaust amount meeting cooling performance required for the pre-cooler 40 can be ensured. - Although the
exhaust port 430 of the present embodiment opens in a direction crossing the fan stream, the exhaust port of the pre-cooler 40 may also open along the fan stream. - A positional relationship between the
engine oil cooler 30 and the pre-cooler 40 described above is described. - The
engine oil cooler 30 and the pre-cooler 40 are longitudinally arranged in the engine access space S1 (FIG. 4 ), and thereby arranged in one position (here, an upper portion) in the circumferential direction in a concentrated manner. Accordingly, a region where theengine oil cooler 30 and the pre-cooler 40 work as resistance to block the fan stream is limited to the one position in the circumferential direction. - On the other hand, if the
engine oil cooler 30 and the pre-cooler 40 are arranged at circumferentially different positions from each other (regardless of the longitudinal positions thereof), the fan stream is blocked by theengine oil cooler 30, and also blocked by the pre-cooler 40. - That is, by arranging the
engine oil cooler 30 and the pre-cooler 40 in the one position in the circumferential direction, a decrease in thrust due to the blockage of the fan stream can be suppressed. Fuel consumption can be thereby improved. - In the present embodiment, the engine oil cooler 30 is arranged behind the
fan 13, and the pre-cooler 40 is arranged posterior to the engine oil cooler 30 in consideration of the importance of theengine oil cooler 30. - Accordingly, the fan stream can be directly introduced into the engine oil cooler 30 from the
fan 13. The heat exchange capacity of the engine oil cooler 30 can be thereby fully exerted. - On the other hand, the pre-cooler 40 introduces the fan stream therein via the
PC intake duct 42 that opens diagonally forward by avoiding interference with the body 31 and theexhaust duct 33 of the engine oil cooler 30 that is arranged anterior to the pre-cooler 40. This is disadvantageous in introducing the fan stream since a pressure loss is larger than that of a case in which the fan stream is introduced from the front as in theengine oil cooler 30. - However, as described in the present embodiment based on one example, the fan stream can be introduced sufficiently enough to secure the heat exchange capacity of the pre-cooler 40 by appropriately designing the positions, forms or the like of the
intake port 420, theexhaust port 430, and theducts - As described above, in accordance with the present embodiment, the heat exchange capacity of each of the
engine oil cooler 30 and the pre-cooler 40 can be secured under the limitation on the installation space for the accessory machinery, and the fuel consumption can be also improved. - In the present embodiment, the circumferential position (region) where the
engine oil cooler 30 and the pre-cooler 40 are arranged is not limited to the upper portion, and may be also a lower portion or other positions. - By the way, the aircraft includes a thrust reverser that generates a portion of thrust toward the front side. The thrust reverser assists braking when an overrun is likely to be caused by using only other braking mechanisms such as a wheel brake of a main landing gear.
- The thrust reverser of the
turbofan engine 10 includes a blocker door 19 (FIG. 6 ) that blocks passage of the fan stream, and reverses the fan stream to the front side, and an air discharge section (not shown) that discharges the fan stream blocked by theblocker door 19 to the diagonally front side. The air discharge section is located in a gap formed between thefirst cowl 171 and thesecond cowl 172 when thesecond cowl 172 is slid backward. - As shown in
FIG. 6 , a plurality ofblocker doors 19 are arranged in thebypass flow path 18 at intervals in a circumferential direction. - For example, the
blocker doors 19 are attached to the inner side of thesecond cowl 172 by hinges so as to be able to be changed in position between a position along the inner periphery of thesecond cowl 172 and a position erected from the inner periphery of the second cowl 172 (FIG. 6 ). - When the thrust reverser is operated, each of the
blocker doors 19 is erected, and a portion of thebypass flow path 18 is blocked by each of theblocker doors 19. The fan stream flowing backward from theblocker doors 19 is thereby reduced. - Therefore, the
intake ports engine oil cooler 30 and the pre-cooler 40 are preferably located anterior to theblocker doors 19. Accordingly, the fan stream is ensured around theintake ports intake ports - In the present embodiment, however, while the
intake port 320 of the engine oil cooler 30 is located anterior to theblocker doors 19, a part of theintake port 420 of the pre-cooler 40 is located posterior to theblocker doors 19 as a result of avoiding interference with theengine oil cooler 30 and the other accessory machinery. - In this case, the
intake port 420 of the pre-cooler 40 is preferably arranged behind (at the back of) a gap between theblocker door 19 and theblocker door 19 adjacent to each other. - Accordingly, the fan stream passing through the gap between the
adjacent blocker doors intake port 420. The heat exchange capacity of the pre-cooler 40 can be secured even during the operation of the thrust reverser. - Therefore, even during the operation of the thrust reverser, it is possible to operate a cabin air-conditioner, an anti-ice system or the like while sufficiently cooling the engine bleed air.
- The constitutions described in the embodiment described above may be also freely selected or changed into other constitutions without departing from the scope of the present invention.
- Although the
engine oil cooler 30 and the pre-cooler 40 are longitudinally arranged on the outer side of thepylon body 21 in the above embodiment, the engine oil cooler and the pre-cooler may be also longitudinally arranged on the inner side of the pylon body in the present invention. When the engine oil cooler and the pre-cooler are arranged in one position in the circumferential direction in a concentrated manner even within the pylon body, a decrease in thrust due to the blockage of the fan stream can be also suppressed.
Claims (7)
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JP2013244762A JP6423999B2 (en) | 2013-11-27 | 2013-11-27 | aircraft |
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JP2013-224762 | 2013-11-27 |
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US20150308340A1 US20150308340A1 (en) | 2015-10-29 |
US20170248077A9 true US20170248077A9 (en) | 2017-08-31 |
US10760489B2 US10760489B2 (en) | 2020-09-01 |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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US10125683B2 (en) * | 2013-06-28 | 2018-11-13 | Aircelle | De-icing and conditioning device for an aircraft |
US10273014B2 (en) * | 2015-09-04 | 2019-04-30 | Safran Aircraft Engines | Oil cooler integrated into the pylon |
FR3089248A1 (en) * | 2018-12-03 | 2020-06-05 | Safran Aircraft Engines | Aircraft engine assembly having an optimized fixing air-oil exchanger system support |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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CN112963861B (en) * | 2021-03-11 | 2022-08-30 | 哈尔滨工业大学 | Dual-fuel precooler with distributable heat exchange area |
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US10273014B2 (en) * | 2015-09-04 | 2019-04-30 | Safran Aircraft Engines | Oil cooler integrated into the pylon |
FR3089248A1 (en) * | 2018-12-03 | 2020-06-05 | Safran Aircraft Engines | Aircraft engine assembly having an optimized fixing air-oil exchanger system support |
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Also Published As
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JP2015101264A (en) | 2015-06-04 |
US10760489B2 (en) | 2020-09-01 |
US20150308340A1 (en) | 2015-10-29 |
JP6423999B2 (en) | 2018-11-14 |
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