CN113320683B - Cavitation-resistant blade with jet flow and wall rolling structure - Google Patents
Cavitation-resistant blade with jet flow and wall rolling structure Download PDFInfo
- Publication number
- CN113320683B CN113320683B CN202110757700.5A CN202110757700A CN113320683B CN 113320683 B CN113320683 B CN 113320683B CN 202110757700 A CN202110757700 A CN 202110757700A CN 113320683 B CN113320683 B CN 113320683B
- Authority
- CN
- China
- Prior art keywords
- jet
- cavity
- flow
- curved surface
- active
- 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.)
- Active
Links
- 238000005096 rolling process Methods 0.000 title claims abstract description 17
- 239000012530 fluid Substances 0.000 claims abstract description 66
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 9
- 230000000149 penetrating effect Effects 0.000 claims abstract description 3
- 230000006835 compression Effects 0.000 claims description 32
- 238000007906 compression Methods 0.000 claims description 32
- 238000005192 partition Methods 0.000 claims description 10
- 230000007423 decrease Effects 0.000 claims 1
- 238000000926 separation method Methods 0.000 abstract description 17
- 230000003628 erosive effect Effects 0.000 abstract description 2
- 238000004088 simulation Methods 0.000 description 6
- 230000002035 prolonged effect Effects 0.000 description 4
- 230000000630 rising effect Effects 0.000 description 4
- 238000009826 distribution Methods 0.000 description 3
- 238000010248 power generation Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000010977 jade Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C3/00—Wings
- B64C3/10—Shape of wings
- B64C3/14—Aerofoil profile
- B64C3/141—Circulation Control Airfoils
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C23/00—Influencing air flow over aircraft surfaces, not otherwise provided for
- B64C23/06—Influencing air flow over aircraft surfaces, not otherwise provided for by generating vortices
- B64C23/065—Influencing air flow over aircraft surfaces, not otherwise provided for by generating vortices at the wing tips
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/32—Rotors
- B64C27/46—Blades
- B64C27/467—Aerodynamic features
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03B—MACHINES OR ENGINES FOR LIQUIDS
- F03B3/00—Machines or engines of reaction type; Parts or details peculiar thereto
- F03B3/12—Blades; Blade-carrying rotors
- F03B3/121—Blades, their form or construction
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03D—WIND MOTORS
- F03D1/00—Wind motors with rotation axis substantially parallel to the air flow entering the rotor
- F03D1/06—Rotors
- F03D1/065—Rotors characterised by their construction elements
- F03D1/0675—Rotors characterised by their construction elements of the blades
-
- 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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
-
- 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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/72—Wind turbines with rotation axis in wind direction
-
- 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
- Y02T50/10—Drag reduction
Abstract
The invention discloses an anti-cavitation blade with a jet flow and wall surface rolling structure, which comprises an airfoil body, wherein an active jet flow cavity which is recessed into the airfoil body from a suction surface is arranged in the airfoil body along the extending direction, an opening of the active jet flow cavity on the suction surface is a jet flow outlet, a jet flow inlet penetrating through one side wing end of the airfoil body is arranged in the active jet flow cavity along the extending direction, and the jet flow inlet is communicated with an active jet flow source; the active jet cavity is internally provided with a rectification tip which is positioned between the jet inlet and the jet outlet and used for prolonging the fluid flow path in a protruding way, and along the fluid flow direction, the overflow area in the active jet cavity is gradually reduced; the invention reduces the area of the vortex area at the upstream of the jet outlet, enables the vortex area at the downstream of the jet outlet to move downwards, inhibits the flow separation capacity of the suction surface of the airfoil, enables the separation point to be closer to the tail edge of the airfoil, has a larger negative pressure area compared with a common active jet structure, prevents cavitation erosion, and obviously improves the lift coefficient of the airfoil.
Description
Technical Field
The invention relates to the field of fluid machinery, in particular to an anti-cavitation blade with jet flow and wall rolling structures.
Background
The wing profile is a basic structure in the field of fluid machinery, and has been widely applied to the fields of wings, propeller wing profiles, wind power generation blade section wing profiles, tidal power generation blade wing profiles and the like in the field of aviation. With the rapid development of scientific technology and fluid machinery industry, particularly with the expansion of application fields, hydraulic machinery such as tidal power generation, marine water jet propellers, underwater vehicles and the like can be widely used, people can not meet the dynamic performance provided by the traditional wing any more, and the requirements on the wing profile performance are also higher and higher. Along with the change of the density and viscosity of a fluid medium, the change of the round-flow Reynolds number and the Stlaugh number is caused, the front edge of the airfoil is more prone to complex unstable flows such as a large number of vortex areas, cavitation flows, cloud cavitation and the like during high-speed operation, cavitation erosion is prone to be formed during long-time operation under the conditions, the wall surface of a hydraulic machine is damaged, vibration noise is induced, and the performance of the airfoil is seriously affected.
In the prior art, in order to optimize the rising resistance and the flow characteristic of the airfoil, an active jet orifice is usually arranged at the front edge of the airfoil, and the active jet is utilized to inhibit laminar flow diversion of the front edge of the airfoil, so that the rising resistance and the flow characteristic of the airfoil are improved. Although the existing active jet technology can achieve a certain optimization effect, the existing active jet port is simpler in structure, and only a single jet channel exists, so that the fluid injected from the jet port is poor in distribution uniformity, and the optimization effect on the rising resistance and the flow characteristic of the wing section is poor; in addition, when the fluid winds the hydrofoil, the density, the viscosity and the wall surface of the hydrofoil of the fluid medium influence, momentum loss can occur on the suction surface of the airfoil, flow separation is further generated, vortex can occur along with the further flowing of the fluid, a local low-pressure area is formed, cavitation phenomenon can occur when the pressure of the local low-pressure area is lower than the gasification pressure of the local fluid at the temperature, and cavitation is one of the important reasons for endangering the safe operation of the hydraulic machinery, so that the problem needs to be solved.
Disclosure of Invention
In order to avoid and overcome the technical problems in the prior art, the invention provides an anti-cavitation blade with jet flow and wall rolling structure. The invention ensures that the active jet flow is more uniformly distributed after leaving the jet flow outlet, reduces the area of the vortex region, inhibits the flow separation capability of the suction surface of the airfoil, and ensures that the separation point is closer to the tail edge of the airfoil so as to obviously improve the lift coefficient and has small cavitation influence range.
In order to achieve the above purpose, the present invention provides the following technical solutions:
the anti-cavitation blade with the jet flow and wall rolling structure comprises an airfoil body, wherein an active jet flow cavity recessed into the airfoil body from a suction surface is formed in the airfoil body along the extending direction, an opening of the active jet flow cavity on the suction surface is a jet flow outlet, a jet flow inlet penetrating through one wing end of the airfoil body is arranged in the active jet flow cavity along the extending direction, and the jet flow inlet is communicated with an active jet flow source; the active jet cavity is internally provided with a rectification tip which is positioned between the jet inlet and the jet outlet and used for prolonging the fluid flow path in a protruding way, and along the fluid flow direction, the overflow area in the active jet cavity is gradually reduced;
the active jet cavity is internally provided with a rectifying section which is positioned on the fluid flow path and cuts off the path along the extending direction of the wing-shaped body, the rectifying section is provided with rectifying holes for the fluid to pass through, and the distance between every two adjacent rectifying holes is gradually increased along the direction away from the jet inlet;
the suction surface of the wing section body is uniformly provided with a spherical cavity positioned at the upstream end of the active jet cavity along the extending direction of the wing section body, a ball which is anastomotic with the spherical cavity in shape and can rotate in the spherical cavity is arranged in the spherical cavity, the spherical cavity is in an opening shape, and the intersection of the opening part and inflow fluid of the suction surface is used for allowing the fluid to enter the spherical cavity to impact the ball so as to enable the ball to rotate.
As a further scheme of the invention: the rectifying pin extends from the suction surface of the airfoil body to the active jet cavity along the airfoil incoming flow direction; the flow straightening tip divides the active jet cavity into a precompression cavity, a transitional compression cavity and a jet compression cavity which are sequentially arranged along the fluid flow direction, a gap between the end part of the flow straightening tip and the active jet cavity is the transitional compression cavity, the precompression cavity is communicated with the jet inlet, and the jet outlet of the jet compression cavity faces the same fluid flow direction as the surface of the suction surface.
As still further aspects of the invention: the rectifying section is a rectifying tube, the rectifying tube is matched with the jet inlet in shape, and the rectifying tube is inserted into the precompression cavity along the jet inlet and fixed.
As still further aspects of the invention: the chord length of the wing-shaped body is L, the distance between the rectifying tube and the front edge of the wing-shaped body is 0.3L, the height of the jet outlet is 0.002L-0.008L, and the distance between the jet outlet and the front edge of the wing-shaped body is 0.2L-0.4L.
As still further aspects of the invention: the jet flow compression cavity is internally provided with a runner partition plate which divides the jet flow compression cavity into at least two runners along the expanding direction.
As still further aspects of the invention: the chord length of the airfoil body is L, the width of the jet outlet is 0.8L, the width of the flow passage partition plate is 0.1L, and the number of the flow passage partition plates is two, so that the jet outlet is uniformly divided into three flow passages with the width of 0.2L.
As still further aspects of the invention: the active jet cavity is a curved cavity, and the cross section of the active jet cavity is in a hook shape.
As still further aspects of the invention: the total area of the holes of the rectifying holes is smaller than the area of the jet inlet.
As still further aspects of the invention: the active jet cavity is composed of a first curved surface, a second curved surface, a third curved surface, a fourth curved surface, a fifth curved surface, a sixth curved surface and a seventh curved surface which are sequentially connected, wherein a gap between the first curved surface and the seventh curved surface is a jet outlet.
As still further aspects of the invention: the cross-sectional curve of the first curved surface is a cubic curve,
wherein: -7-6; b is more than or equal to 6 and less than or equal to 7; -2-1 and-2; d is more than or equal to 0 and less than or equal to 1;
the cross-section curve of the second curved surface is a cubic curve,
wherein: -920 < e < minus 900; f is more than or equal to 1200 and less than or equal to 1220; -530-520 g; h is more than or equal to 75 and less than or equal to 80;
the section curve of the third curved surface is a cubic curve,
wherein: -45-40; -45-40; -15-20 and k-15; -2 is less than or equal to l is less than or equal to-1;
the cross-section curve of the fourth curved surface is a cubic curve,
wherein: -155-145 and m-145; n is more than or equal to 140 and less than or equal to 145; -50-40; p is more than or equal to 4 and less than or equal to 5;
the section curve of the fifth curved surface is a cubic curve,
wherein: q is more than or equal to 20 and less than or equal to 25; -25-20; s is more than or equal to 8 and less than or equal to 10; -2 is less than or equal to t is less than or equal to-1;
wherein the boundary conditions are:
x 1 ＝3.10 y 1 ＝0.75
x 5 ＝2.65 y 5 ＝0.29
x 1 ＝x 2 ＝2.36 y 1 ＝y 2 ＝0.53
x 2 ＝x 3 ＝2.17 y 2 ＝y 3 ＝0.19
x 3 ＝x 4 ＝2.99 y 3 ＝y 4 ＝-0.45
x 4 ＝x 5 ＝3.58 y 4 ＝y 5 ＝0
the section curve of the sixth curved surface is an arc curve, the chord length of the airfoil body is L, and the radius of the arc curve of the sixth curved surface is 0.007L;
the cross-section curve of the seventh curved surface is a cubic curve, and the overflow area of the jet outlet between the seventh curved surface and the first curved surface is linearly reduced by 1.2 times along the fluid flow direction.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the invention, the rectification tip is creatively arranged in the traditional active jet cavity in a protruding way so as to be transversely spanned between the jet inlet and the jet outlet, so that the linear flow track of fluid from the jet inlet to the jet outlet is changed into an arc-shaped flow track which is wound around the rectification tip, the flow distance of the fluid is prolonged in a limited active jet cavity space, meanwhile, through the separation of the rectification tip, the flow passing area along the fluid flowing to the active jet cavity is gradually reduced, after the fluid with a certain speed is injected into the active jet cavity by the active jet source, the fluid is continuously compressed in the cavity, and the uniformity of the speed after the fluid is injected is improved; the flow distance of the fluid in the limited space is prolonged, so that the flow time is prolonged, the sufficient compression diffusion time is obtained in the active jet cavity, the fluid is distributed more uniformly after leaving the jet outlet, the area of a vortex area at the upstream of the jet outlet is reduced, the vortex area at the downstream of the jet outlet is reduced, the flow separation capacity of the suction surface of the airfoil is inhibited, the separation point is closer to the tail edge of the airfoil, compared with the common active jet structure, a larger negative pressure area is provided, cavitation is prevented, and the lift coefficient of the airfoil is obviously improved; the rectifying section and the rectifying holes on the surface of the rectifying section uniformly compensate streamline of the suction surface of the airfoil, so that the streamline is uniformly distributed, the lift coefficient of the airfoil is further improved, and the suction surface is subjected to energy compensation; when the fluid drives the ball structure to rotate, the energy of the fluid near the separation point is increased, so that the flow separation point is greatly moved backwards, cavitation flow around the hydrofoil can be better controlled, the cavitation area of the suction surface is greatly reduced, the proportion of cavitation is reduced, the lift-drag ratio of the airfoil is greatly improved, and the cavitation performance is improved.
2. The rectification tip extends from the airfoil suction surface into the active jet cavity, the active jet cavity is artificially divided into a precompression cavity for inflow, a jet compression cavity for outflow and a transitional compression cavity for transitional action in the middle of the jet compression cavity; due to the separation of the rectifying tips and the matching of the rectifying tips and the cavity walls, the fluid is continuously compressed through each cavity along the fluid flow direction, and finally uniformly diffused and ejected.
3. According to the invention, the rectifying tube which is matched with the jet inlet in size is inserted into the active jet cavity, and the fluid is distributed and compressed before entering the active jet cavity, so that the fluid is uniformly distributed after entering the active jet cavity, and the subsequent bypass phenomenon is prevented; and by designing the total area of the rectifying holes to be smaller than the area of the jet inlet, the fluid can be pre-compressed before entering the active jet cavity, so that the fluid flows uniformly.
4. The flow passage partition plate is arranged in the jet flow compression cavity to divide the jet flow outlet into a plurality of flow passages, so that the uniformity of fluid injection is improved, and the flow passage partition plate has the thickness, so that the function of compressing the flow passage area is achieved, and the fluid is continuously compressed in the fluid injection process.
5. According to the invention, the active jet cavity is subjected to specific parameterization setting, so that the parameters are optimized, and the processing is more convenient.
Drawings
FIG. 1 is a cross-sectional view of an airfoil along the chord length.
FIG. 2 is a three-dimensional schematic of an airfoil.
FIG. 3 is a three-dimensional schematic view of an airfoil with one of its wing tips cut away.
Fig. 4 is a cross-sectional view of an active jet cavity.
Fig. 5 is a cross-sectional view of the active jet cavity after insertion of the rectifier tube.
Fig. 6 is a schematic structural diagram of the rectifying tube.
Fig. 7 is a cross-sectional view of the rectifier tube.
FIG. 8 is a top view of an airfoil of the present invention.
FIG. 9 is a profile of airfoil suction side vortices without active jet structure.
FIG. 10 is a graph of airfoil suction side vortex profile with a conventional active jet configuration.
FIG. 11 is a graph of the suction side vortex profile of an airfoil having an active jet configuration of the present invention.
FIG. 12 is a graph of the vortex profile of the suction side of an airfoil having an active jet structure with a rectifier tube inserted therein in accordance with the present invention.
FIG. 13 is a simulation of airfoil streamlines with a generic active jet structure.
FIG. 14 is a schematic view of an airfoil streamline simulation with the active jet structure of the present invention.
FIG. 15 is a schematic view of an airfoil streamline simulation with an active jet structure of the present invention with a rectifier tube inserted therein.
FIG. 16 is a three-dimensional cavitation structural view of an airfoil without a ball structure at the front end.
FIG. 17 is a three-dimensional cavitation structural view of an airfoil having a ball structure at the leading end.
FIG. 18 is a cross-sectional cavitation volume fraction distribution plot for an airfoil without a ball bearing structure at the leading end.
FIG. 19 is a cross-sectional cavitation volume fraction distribution plot for an airfoil having a ball structure at the leading end.
In the figure: 10. an airfoil body; 101. a suction surface; 102. a ball; 20. an active jet cavity; 201. a flow passage partition plate; 202. a rectifying tip; 203. rectifying tube; 2031. jet holes; 2041. a first curved surface; 2042. a second curved surface; 2043. a third curved surface; 2044. a fourth curved surface; 2045. a fifth curved surface; 2046. a sixth curved surface; 2047. a seventh curved surface; u, precompression chamber; v, a transitional compression cavity; w, jet compression chamber.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1 to 19, in the embodiment of the present invention, an anti-cavitation blade with jet flow and wall rolling structure includes an airfoil body 10, and the present invention takes the NACA0015 airfoil as an example, and the structure of the present invention can be practically applied to various airfoils. As shown in fig. 1, 2 and 3, with the chord length of the airfoil body 10 being L, the airfoil extension length being 0.8L, an active jet cavity 20 recessed from the suction surface 101 into the airfoil body 10 is provided in the airfoil body 10 along the extension direction. The length of the active jet cavity 20 along the wing section stretching direction is also 0.8L, and thin walls exist at the wing ends at two sides of the wing section to seal the two ends of the active jet cavity 20, so that the thickness of the thin walls is negligible.
The fluid in the invention is divided into two parts, one part is active jet injected into the active jet cavity by the active jet source, and the other part is fluid flowing through the surface of the airfoil; the fluid in the invention refers to the active jet which is injected into the active jet cavity by the active jet source except that the fluid is explicitly indicated to be the surface inflow of the airfoil.
The active jet cavity 20 is a smooth curved surface; the suction surface 101 extends into the active jet cavity 20 along the wing-shaped inflow direction to form an arc-shaped rectifying tip 202, and the rectifying tip 202 extends into the active jet cavity 20 to enable the active jet cavity 20 to be in a hook-jade shape.
Due to the separation of the rectifying tips 202, the flow path of the fluid in the active jet cavity 20 is changed from a straight line type to an arc type, the flow path is prolonged, and the flow area of the active jet cavity 20 is gradually reduced along the fluid flow direction due to the existence of the rectifying tips 202.
The opening of the active jet cavity 20 on the suction surface 101 of the airfoil body 10 is the jet outlet.
After the rectifying pin 202 stretches into the active jet cavity 20, the active jet cavity 20 is divided into a precompression cavity u, a transitional compression cavity v and a jet compression cavity w which are sequentially arranged along the fluid flow direction, a gap between the rectifying pin 202 and the active jet cavity 20 is the transitional compression cavity v, the jet compression cavity w is a tail section of the active jet cavity 20 and is connected with the suction surface 101, and the fluid is finally ejected from a jet outlet of the jet compression cavity w.
One side wing end of the wing-shaped body 10 is provided with an opening on the thin wall of the closed active jet cavity 20, the opening is communicated with the precompression cavity u, the opening is a jet inlet, the jet inlet is communicated with an active jet source, the active jet source provides active jet with a certain jet speed from the jet inlet into the active jet cavity 20, and the incoming flow speed of the wing-shaped suction surface is V 1 The jet velocity of the active jet source is V 2 ，0.3V 2 ≤V 1 ≤1.5V 2 。
The jet inlet is not limited in shape, and is preferably a circular jet inlet; the rectifier 203 having the same shape as the jet inlet is inserted into the jet inlet, and after the end of the rectifier 203 away from the jet inlet is abutted against the cavity wall of the active jet cavity 20, the rectifier 203 is fixed in any manner, for example, by welding or riveting. Jet holes 2031 are formed in the pipe body of the rectifying pipe 203, the jet holes 2031 are arranged at intervals along the length direction of the rectifying pipe 203, and the distance between every two adjacent jet holes 2031 is gradually increased along the direction away from the jet inlet. Since the rectifier 203 is in the fluid flow path, the fluid must enter the precompression chamber u through the jet orifice 2031 in the rectifier 203 after entering the jet inlet.
In order to optimize the structure, the distance between the axis of the rectifying tube 203 and the front edge of the airfoil is kept at 0.3L, the height of the jet outlet is kept at 0.002L-0.008L, and the distance between the jet outlet and the front edge of the airfoil is kept at 0.2L-0.4L by taking the chord length L of the airfoil body 10 as a reference.
However, the rectifying tube 203 is not the only choice, and by inserting a rectifying plate from the jet inlet and fixing it, it spans between the precompression chamber u and the transitional compression chamber v, and arranging rectifying holes at intervals on the plate body, keeping the distance between adjacent rectifying holes gradually increasing along the direction away from the jet inlet, it can function as the rectifying tube 203.
To ensure the compression function on the fluid, the total area of the holes on the rectifying tube 203 or the rectifying plate is smaller than the area of the jet inlet; the rectifying tube 203 or rectifying plate has a thickness of 0.01L and a surface pore diameter of 0.0125L.
In order to further improve the compression and rectification performance of the jet compression chamber w, a flow passage partition plate 201 is provided in the jet compression chamber w to partition the jet compression chamber w into a plurality of flow passages. With the chord length of the airfoil body 10 being L, the width of the jet outlet along the airfoil body 10 is 0.8L, and at this time, the flow channel splitter plate 201 is preferably two, and each block has a width of 0.1L, so that the jet outlets of the jet compression cavity w are uniformly separated into three flow channels of 0.2L.
The active jet cavity 20 is specifically formed by a first curved surface 2041, a second curved surface 2042, a third curved surface 2043, a fourth curved surface 2044, a fifth curved surface 2045, a sixth curved surface 2046, and a seventh curved surface 2047 that are sequentially connected, and a gap between the first curved surface 2041 and the seventh curved surface 2047 is a jet outlet of the jet compression cavity w, which is specifically described below.
The active jet cavity 20 is cut along the chord length direction of the airfoil body 10, the cross-sectional curve of the first curved surface 2041 is a cubic curve,
-7≤a≤-6；6≤b≤7；-2≤c≤-1；0≤d≤1；
the cross-sectional curve of the second curved surface 2042 is a cubic curve,
-920≤e≤-900；1200≤f≤1220；-530≤g≤-520；75≤h≤80；
the cross-sectional curve of the third curved surface 2043 is a cubic curve,
-45≤i≤-40；-45≤j≤-40；-15≤k≤-20；-2≤l≤-1；
the cross-sectional curve of the fourth curved surface 2044 is a cubic curve,
-155≤m≤-145；140≤n≤145；-50≤o≤-40；4≤p≤5；
the cross-sectional curve of the fifth curved surface 2045 is a cubic curve,
20≤q≤25；-25≤r≤-20；8≤s≤10；-2≤t≤-1；
wherein the boundary conditions are:
x 1 ＝3.10 y 1 ＝0.75
x 5 ＝2.65 y 5 ＝0.29
x 1 ＝x 2 ＝2.36 y 1 ＝y 2 ＝0.53
x 2 ＝x 3 ＝2.17 y 2 ＝y 3 ＝0.19
x 3 ＝x 4 ＝2.99 y 3 ＝y 4 ＝-0.45
x 4 ＝x 5 ＝3.58 y 4 ＝y 5 ＝0
the section curve of the sixth curved surface 2046 is a circular arc curve, the chord length of the airfoil body 10 is L, the radius of the circular arc curve of the sixth curved surface is 0.007L, and the circular arc is a semicircle.
The cross-sectional curve of the seventh curved surface 2047 is a cubic curve, and the flow area of the jet outlet between the seventh curved surface 2047 and the first curved surface 2041 is linearly reduced by 1.2 times along the fluid flow direction. Flow area S along the fluid flow direction at the end of the single flow channel of the jet outlet 1 Is 0.04mm 2 -0.16mm 2 The flow area of the initial end of the single flow channel is S 2 Is 2.5S 1 -4S 1 。
Since the flow-through area is determined in a linear relationship and the first curved surface 2041 is also known, the cross-sectional curve of the seventh curved surface 2047 can be obtained from the cross-sectional curve of the first curved surface 2041.
9-12 are vortex profiles of the suction side of an airfoil;
as shown in fig. 9, the suction side of a conventional airfoil has a large number of vortices.
As shown in FIG. 10, the airfoil with the conventional active jet structure has reduced vortex area on the suction side of the airfoil, but a large number of vortex areas are still present at the jet outlet of the suction side of the airfoil.
As shown in FIG. 11, the wing profile with the active jet structure of the invention has the advantages that compared with the common jet structure, the area of the vortex area at the upstream of the jet outlet of the wing profile suction surface is obviously reduced, the area of the vortex area at the jet outlet is also obviously reduced, the whole vortex area at the downstream of the jet outlet moves downwards, namely the separation point moves downwards, the jet obviously inhibits the flow separation capability of the wing profile suction surface, so that the separation point is closer to the tail edge of the wing profile, and compared with the common active jet structure, the wing profile has a larger negative pressure area, and the lift coefficient of the wing profile is obviously improved.
As shown in fig. 12, in the airfoil with the active jet structure, a rectifying tube is further inserted into the active jet cavity, so that the scroll area downstream of the jet outlet is larger in downward movement range, the scroll area upstream of the jet outlet is larger in reduction range, and the overall lift coefficient is improved more.
FIGS. 13-15 are flow line simulation graphs of airfoil surfaces;
as shown in fig. 13, the suction surface of the airfoil of the conventional active jet structure is piled up far from the jet inlet, and flows around from the far jet inlet, and only a small amount of fluid on the suction surface near the jet inlet compensates the energy of the airfoil suction surface, which is caused by the fact that the fluid cannot be fully diffused in the active jet structure.
As shown in FIG. 14, the airfoil with the active jet structure has the advantages that the streamline of the suction surface is uniformly distributed along the extending direction of the airfoil, the vortex is effectively inhibited, the jet obviously inhibits the flow separation capacity of the suction surface of the airfoil, so that the separation point is closer to the tail edge at the downstream of the suction surface of the airfoil, and the lift coefficient is improved.
As shown in fig. 15, in the airfoil having the active jet structure of the present invention, after the rectifier tube is inserted, a part of the vortex area at the downstream of the jet outlet is further eliminated, so that the lift coefficient of the airfoil is further improved.
Numerical simulation tests are respectively carried out on an NACA0015 common airfoil, an NACA0015 airfoil containing a common jet structure and an NACA0015 airfoil containing a jet structure of the invention, and an NACA0015 airfoil with rectifier tubes inserted in the jet structure of the invention, according to 8-degree attack angle, 10m/s incoming flow speed and 5m/s active jet source jet speed, and the results of the rising resistance coefficients of the four schemes are shown in the following table:
the common active jet structure can be found that the lift coefficient is slightly improved while the resistance coefficient is greatly reduced, and the lift coefficient of the airfoil is greatly improved while the resistance coefficient is basically unchanged after the original common active jet structure is replaced by the active jet structure of the invention, so that the energy loss of the suction surface of the airfoil is effectively compensated. After the rectifying tube is inserted into the active jet structure, the lift coefficient is improved again, and the resistance coefficient is maintained stable.
In order to reduce cavitation influence range, the surface of the suction surface 101 of the airfoil body 10 is uniformly provided with a spherical cavity at the upstream end of the active jet cavity 20 along the extending direction of the airfoil body 10, a ball 102 which is in fit with the spherical cavity in shape and can rotate in the spherical cavity is arranged in the spherical cavity, the spherical cavity is in an opening shape, and the opening part is intersected with the inflow fluid of the suction surface 101 so that the fluid enters the spherical cavity to impact the ball 102 to rotate.
A plurality of rows of balls 102 are arranged at the upstream end of the active jet cavity along the wing-shaped expanding direction, and the distance between the adjacent balls 102 along the wing-shaped expanding direction is D, wherein D/L is more than or equal to 1/20 and less than or equal to 1/5; the spacing between adjacent rows of balls 102 is H, where 1/15.ltoreq.H/L.ltoreq.1/4.
The ball structures may be used alone, preferably in combination with an active jet structure.
As shown in fig. 16 and 17, the three-dimensional cavitation simulation is performed on the upstream end of the active jet cavity at an incoming flow speed of 10m/s and an attack angle of 8 degrees, so that the original airfoil has a larger cavitation area range, and the cavitation area is greatly reduced after the ball structure is added to the front end of the suction surface.
As shown in fig. 18 and 19, the middle section of the airfoil is selected as a research object, and the cavitation volume fraction of the original scheme is relatively large, the cavitation occupancy is relatively large, and the proportion of the cavitation is greatly reduced after the ball structure is added at the front end of the airfoil.
| Scheme for the production of a semiconductor device | lift/N | resistance/N | Lift-drag ratio |
| Original scheme | 67.48 | 9.80 | 6.89 |
| Ball structure | 85.23 | 8.41 | 10.13 |
The lift resistance characteristic of the airfoil profile can be obtained through calculation, the lift force of the original scheme is 67.48N, the resistance is 9.80N, and the cavitation influence range and the cavitation occupancy ratio are relatively large. After the ball structure is added at the front end of the airfoil, the lift force is raised to 85.23N, the resistance is reduced to 8.41N, the lift-drag ratio is greatly improved, and the cavitation performance of the airfoil is well improved.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.
Claims (10)
1. The cavitation-resistant blade with the jet flow and wall rolling structure is characterized by comprising an airfoil body (10), wherein an active jet flow cavity (20) which is recessed into the airfoil body (10) from a suction surface (101) is formed in the airfoil body (10) along the expanding direction, an opening of the active jet flow cavity (20) on the suction surface (101) is a jet flow outlet, and the active jet flow cavity (20) is provided with a jet flow inlet penetrating through one wing end of the airfoil body (10) along the expanding direction, and the jet flow inlet is communicated with an active jet flow source; the active jet cavity (20) is internally provided with a rectifying pin (202) which is positioned between the jet inlet and the jet outlet and used for prolonging the fluid flow path in a protruding way, and along the fluid flow direction, the overflow area in the active jet cavity (20) is gradually reduced;
a rectifying section which is positioned on the fluid flow path and cuts off the path is arranged in the active jet cavity (20) along the expanding direction of the wing-shaped body (10), a rectifying hole for the fluid to pass through is formed in the rectifying section, and the distance between every two adjacent rectifying holes is gradually increased along the direction away from the jet inlet;
the suction surface (101) of the wing-shaped body (10) is provided with spherical cavities at the upstream end of the active jet cavity (20) along the extending direction of the wing-shaped body (10), balls (102) which are anastomotic with the spherical cavities in shape and can rotate in the spherical cavities are arranged in the spherical cavities, the spherical cavities are in an opening shape, and the intersection of the opening part and inflow fluid of the suction surface (101) is provided for the fluid to enter the spherical cavities to impact the balls (102) so as to enable the fluid to rotate.
2. Anti-cavitation blade with jet and wall rolling structure according to claim 1, characterized in that the rectifying tip (202) extends from the suction surface (101) of the airfoil body (10) into the active jet cavity (20) in the airfoil inflow direction; the flow straightening tip (202) divides the active jet flow cavity (20) into a precompression cavity (u), a transitional compression cavity (v) and a jet flow compression cavity (w) which are sequentially arranged along the fluid flow direction, a gap between the end part of the flow straightening tip (202) and the active jet flow cavity (20) is the transitional compression cavity (v), the precompression cavity (u) is communicated with the jet flow inlet, and the jet flow outlet of the jet flow compression cavity (w) faces the same fluid flow direction as the surface of the suction surface (101).
3. An anti-cavitation blade with jet and wall rolling structure according to claim 2, characterized in that the rectifying section is a rectifying tube (203), the rectifying tube (203) being shaped to coincide with the jet inlet, inserted into the precompression chamber (u) along the jet inlet and fixed.
4. An anti-cavitation blade with jet and wall rolling structure according to claim 3, characterized in that the distance between the rectifying tube (203) and the airfoil front is 0.3L, the jet outlet height is 0.002L-0.008L, the distance between the jet outlet and the airfoil front is 0.2L-0.4L.
5. An anti-cavitation blade with jet and wall rolling structure according to any one of claims 2-4, characterized in that a flow passage partition plate (201) is arranged in the jet compression chamber (w) to partition the jet compression chamber (w) into at least two flow passages along the expanding direction.
6. The cavitation-resistant blade with jet and wall rolling structure according to claim 5, wherein the jet outlet width is 0.8L, the width of the flow path dividing plate (201) is 0.1L, the number of the flow path dividing plate (201) is two, and the jet outlet is divided into three flow paths with the width of 0.2L.
7. An anti-cavitation blade with jet and wall rolling structure according to any of claims 1-4, characterized in that the active jet cavity (20) is a curved cavity with a cross section in the shape of a hook.
8. An anti-cavitation vane having a jet and wall rolling structure according to any one of claims 1 to 4, wherein the total orifice area of the rectifying orifice is smaller than the jet inlet area.
9. The cavitation-resistant blade with jet and wall rolling structure according to any one of claims 1-4, wherein the active jet cavity (20) is composed of a first curved surface (2041), a second curved surface (2042), a third curved surface (2043), a fourth curved surface (2044), a fifth curved surface (2045), a sixth curved surface (2046) and a seventh curved surface (2047) which are sequentially connected, wherein a gap between the first curved surface (2041) and the seventh curved surface (2047) is a jet outlet.
10. The device of claim 9 having an injectionThe cavitation-resistant blade with the flow and wall rolling structure is characterized in that the section curve of the first curved surface (2041) is a cubic curve,
wherein: -7-6; b is more than or equal to 6 and less than or equal to 7; -2-1 and-2; d is more than or equal to 0 and less than or equal to 1;
the cross-section curve of the second curved surface (2042) is a cubic curve,
wherein: -920 < e < minus 900; f is more than or equal to 1200 and less than or equal to 1220; -530-520 g; h is more than or equal to 75 and less than or equal to 80;
the cross-section curve of the third curved surface (2043) is a cubic curve,
wherein: -45-40; -45-40; -15-20 and k-15; -2 is less than or equal to l is less than or equal to-1;
the cross-section curve of the fourth curved surface (2044) is a cubic curve,
wherein: -155-145 and m-145; n is more than or equal to 140 and less than or equal to 145; -50-40; p is more than or equal to 4 and less than or equal to 5;
the cross-section curve of the fifth curved surface (2045) is a cubic curve,
wherein: q is more than or equal to 20 and less than or equal to 25; -25-20; s is more than or equal to 8 and less than or equal to 10; -2 is less than or equal to t is less than or equal to-1;
wherein the boundary conditions are:
x 1 ＝3.10 y 1 ＝0.75
x 5 ＝2.65 y 5 ＝0.29
x 1 ＝x 2 ＝2.36 y 1 ＝y 2 ＝0.53
x 2 ＝x 3 ＝2.17 y 2 ＝y 3 ＝0.19
x 3 ＝x 4 ＝2.99 y 3 ＝y 4 ＝-0.45
x 4 ＝x 5 ＝3.58 y 4 ＝y 5 ＝0
the section curve of the sixth curved surface (2046) is an arc curve, the chord length of the airfoil body (10) is L, and the radius of the arc curve of the sixth curved surface is 0.007L;
the cross-section curve of the seventh curved surface (2047) is a cubic curve, and the overflow area of the jet outlet between the seventh curved surface (2047) and the first curved surface (2041) linearly decreases by 1.2 times along the fluid flow direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110757700.5A CN113320683B (en) | 2021-07-05 | 2021-07-05 | Cavitation-resistant blade with jet flow and wall rolling structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110757700.5A CN113320683B (en) | 2021-07-05 | 2021-07-05 | Cavitation-resistant blade with jet flow and wall rolling structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113320683A CN113320683A (en) | 2021-08-31 |
| CN113320683B true CN113320683B (en) | 2023-07-14 |
Family
ID=77425633
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110757700.5A Active CN113320683B (en) | 2021-07-05 | 2021-07-05 | Cavitation-resistant blade with jet flow and wall rolling structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113320683B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116222952B (en) * | 2023-05-10 | 2023-07-04 | 中国航空工业集团公司哈尔滨空气动力研究所 | Air suction device for reducing thickness of boundary layer of wind tunnel floor |
| CN117408187B (en) * | 2023-12-14 | 2024-03-01 | 中国科学院合肥物质科学研究院 | Guide structure for controlling cavitation of hydraulic machinery |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007007108A1 (en) * | 2005-07-13 | 2007-01-18 | City University | An element for generating a fluid dynamic force |
| CN109989876A (en) * | 2017-12-29 | 2019-07-09 | 江苏金风科技有限公司 | Blade and wind power generating set including it |
| CN113044201A (en) * | 2021-04-29 | 2021-06-29 | 合肥工业大学 | Wing section with active jet structure |
-
2021
- 2021-07-05 CN CN202110757700.5A patent/CN113320683B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007007108A1 (en) * | 2005-07-13 | 2007-01-18 | City University | An element for generating a fluid dynamic force |
| CN109989876A (en) * | 2017-12-29 | 2019-07-09 | 江苏金风科技有限公司 | Blade and wind power generating set including it |
| CN113044201A (en) * | 2021-04-29 | 2021-06-29 | 合肥工业大学 | Wing section with active jet structure |
Non-Patent Citations (1)
| Title |
|---|
| 合成射流对钝尾缘翼型气动特性的影响;程晓龙;马朝臣;刘恒;杨策;;机械工程学报(第04期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113320683A (en) | 2021-08-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113320683B (en) | Cavitation-resistant blade with jet flow and wall rolling structure | |
| CN110030036B (en) | Impact split-joint air film cooling structure of turbine blade tail edge | |
| Chen et al. | Location effect of boundary layer suction on compressor hub-corner separation | |
| CN111734577B (en) | Slit type wind turbine blade device and slit method | |
| DE102010023017A1 (en) | Humpback whale blower, method for locally improving the flow in turbomachinery and vehicles | |
| CN106050736B (en) | A kind of centrifugal blower noise reduction leaf blade structure | |
| CN113044201B (en) | Airfoil with active jet structure | |
| CN107152419A (en) | A kind of big bending angle compressor stator blade of root series connection multistage blade profile | |
| CN112922674B (en) | Turbine blade with air film cooling groove | |
| CN113586163B (en) | Wall surface rolling type blade with active jet structure | |
| CN113107611B (en) | Turbine blade trailing edge cooling structure based on double-throat pneumatic vectoring nozzle and trailing path control method thereof | |
| WO2020042212A1 (en) | Coupled bionic optimization-based vane pump impeller | |
| CN212130558U (en) | Turbine blade structure with truncated ribs and semi-split seam at tail edge | |
| CN113187644B (en) | Active jet structure for improving cavitation flow around hydrofoil | |
| CN104454656A (en) | Flow control method adopting hole-type circumferentially slotted casing treatment with back cavities | |
| CN204877684U (en) | Be applied to hole - sawtooth groove structure of blade film cooling | |
| CN115289499B (en) | Hollow support plate of gas inlet of combustion chamber of gas turbine | |
| CN116717499A (en) | Hydrofoil blade top leakage flow vortex eliminating device based on passive jet | |
| CN113187729B (en) | Axial-flow pump for controlling eddy current and improving performance | |
| CN113251152B (en) | Improved generation reduces separation vortex anti-cavitation valve | |
| CN203009310U (en) | Cavitation-resistant type vane pump | |
| CN115749969A (en) | Rotor blade with self-air-entraining front edge and self-adaptive air-jet blade top | |
| CN210829594U (en) | Vertical axis wind turbine provided with in-vitro fluidic device | |
| CN114382553A (en) | High-blockage-ratio rib laminate cooling structure and cooling method for middle chord area of turbine blade | |
| CN113217462A (en) | Subsonic vortex blowing type compressor blade |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |