Rotating head configuration for drag reduction by differential pressure and friction on a vehicle

Abstract

The application discloses a rotating head configuration of a vehicle differential pressure and friction drag reduction, comprising a turbine disc body and blades; the turbine disc body comprises an integrally formed hub head tip and a hub; the hub head tip is located at the front end of the hub, and the rear end of the hub is provided with a disc matching surface; the blades are provided with a plurality of blades which are installed on the outer wall of the hub at equal intervals in the circumferential direction; the blade comprises a blade leading edge surface, a blade trailing edge surface, a blade pressure surface and a blade suction surface; the blade leading edge surface is arranged close to the hub head tip, and the blade trailing edge surface is arranged close to the disc matching surface; wherein the hub is a rotary body structure formed by rotating an inner concave arc line; the plurality of blades are arranged in a spiral gradually expanding manner along the outer wall of the hub, and the height of the blade and the distance between two adjacent blades are increased in the spiral direction in sequence. The application can significantly reduce the differential pressure resistance and friction resistance received by the vehicle, and correspondingly reduce the thermal load, effectively improving the aerodynamic performance of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of navigation equipment, in particular to a rotating head configuration for reducing pressure difference and friction drag of a vehicle. BACKGROUND

[0002] When air vehicles (such as aircraft, missiles, rockets), underwater vehicles (such as submarines), rail trains, vehicles and other navigation equipment are in motion, there are fluid drag that hinders navigation. The existence of drag makes powerful propulsion devices necessary, and the greater the drag, the lower the upper limit of the speed. The existence of drag can be generally divided into two forms: pressure difference drag and friction drag. After the existing vehicles are optimized in fluid shape, the available drag reduction techniques are only surface treatment (groove, bionic skin), installation of vortex generators to delay separation, etc., which can only reduce friction drag to a limited extent.

[0003] For high-speed vehicles, such as hypersonic vehicles, there is also the problem of severe aerodynamic heating of the head. Hypersonic vehicles mostly use blunt heads to reduce drag and heat, but the bow shock will be generated due to the high compression of the oncoming airflow on the head at high Mach numbers, which will generate very high pressure in the front, resulting in high aerodynamic drag during atmospheric flight. Even if the blunt body can reduce the aerodynamic heating to a certain extent, the strong thermal load on the head of the vehicle is still large, which will cause ablation of the surface material of the vehicle and even failure or damage of the internal electronic equipment.

[0004] At present, the main methods to reduce the drag on the head of the vehicle are to install a needle on the front end of the vehicle, to use reverse jet flow and energy deposition. The installation of a needle belongs to passive flow control, and the local heat flux density is extremely high and is prone to ablation. Reverse jet flow belongs to active flow control, and the applicable angle of attack range is small, which may erode the surface of the vehicle and the engine inlet. The laser plasma in energy deposition has little interference to the overall flow field, but it requires high power of the laser emitter. In summary, there is still much room for development in designing new hypersonic vehicle head heat reduction and drag reduction devices.

[0005] Therefore, a rotating head configuration for reducing pressure difference and friction drag of a vehicle is provided. SUMMARY

[0006] The purpose of the present application is to provide a rotating head configuration for reducing pressure difference and friction drag of a vehicle, which aims to solve or improve at least one of the above technical problems.

[0007] To achieve the above purpose, the present application provides the following scheme: the present application provides a rotating head configuration for reducing pressure difference and friction drag of a vehicle, characterized in that it comprises:

[0008] A turbine disc body comprises an integrally formed hub head tip and a hub; the hub head tip is located at the front end of the hub, and the rear end of the hub is provided with a disc matching surface;

[0009] A plurality of blades are circumferentially and equidistantly arranged on the outer wall of the hub; the blade comprises a blade leading edge surface, a blade trailing edge surface, a blade pressure surface and a blade suction surface; the blade leading edge surface is arranged close to the hub head tip, and the blade trailing edge surface is arranged close to the disc matching surface;

[0010] The hub is a rotary body structure formed by rotating an inner concave arc line; the plurality of blades are arranged in a spiral and gradually expanded manner along the outer wall of the hub, and the height of the blade and the distance between two adjacent blades are gradually increased in the spiral direction.

[0011] According to the rotating head configuration for reducing drag of a vehicle by differential pressure and friction provided by the application, the hub head tip is provided with a rounded corner.

[0012] According to the rotating head configuration for reducing drag of a vehicle by differential pressure and friction provided by the application, the disc matching surface is a plane, the edge of the disc matching surface is integrally machined with the rear end edge of the hub, and the disc matching surface is used to connect the shaft body.

[0013] According to the rotating head configuration for reducing drag of a vehicle by differential pressure and friction provided by the application, the center of the disc matching surface is taken as the coordinate origin, the x direction, the y direction and the z direction form the coordinate axes respectively, and a rectangular coordinate system is established;

[0014] The disc matching surface is the plane where the y coordinate axis and the z coordinate axis are located, and the inner concave arc line is located in the plane where the x coordinate axis and the z coordinate axis are located; the two end points of the inner concave arc line are respectively set as point A and point B, the coordinate origin is set as point O, the distance from point O to point B is the radius r of the disc matching surface, and the distance from point O to point A along the x axis is d;

[0015] The calculation formula of the inner concave arc line is z = r * tanh (k * x) + r, (-d < x < 0);

[0016] Wherein: k is defined as a shape factor, representing the inclination of the inner concave arc line, 0.06 < k < 0.17; 0.75 < r / d < 1.3.

[0017] According to the rotating head configuration for reducing drag of a vehicle by differential pressure and friction provided by the application, the shape of the blade leading edge surface is rectangular, and the blade leading edge surface is arranged in parallel with the plane where the x coordinate axis and the z coordinate axis are located;

[0018] The length of the blade leading edge surface is h1, and 0.04 < h1 / r < 0.12.

[0019] According to the application, the shape of the blade trailing edge surface is rectangular, the length of the blade trailing edge surface is h2, 0.15 < h2 / r < 0.4, and the width of the blade trailing edge surface is d2, and d2 is in the range of 0.5-1.5 mm.

[0020] According to the application, the angle between the blade trailing edge surface and the plane of the x coordinate axis and the z coordinate axis is alpha, and 40° < alpha < 60°.

[0021] According to the application, the number of the blades is not less than six.

[0022] According to the application, the blade suction surface is a concave surface, and the blade pressure surface is a convex surface.

[0023] According to the application, the radius of the round corner is in the range of 4-10 mm.

[0024] The application has the following technical effects:

[0025] The application adopts a plurality of blades arranged along the hub surface of the hub at equal intervals in the circumferential direction, the height of the blade and the distance between the adjacent two blades are increased in the spiral direction, at the air inlet, the height of the blade is small, which can quickly guide the air flow into the turbine disc, reduce the deflection and separation of the air flow, then the height of the blade is gradually increased, so that the air flow keeps stable and uniform flow, reduces the resistance and reverse flow, and meets the dynamic change requirement of high-speed air flow; meanwhile, with the increase of the blade height, the increase of the flow passage width also effectively reduces the pressure drop in the flow passage, so that the air flow is more stable when passing through the blade, reduces the sharp compression and turbulent flow of the air flow, reduces the energy loss caused by the pressure drop, optimizes the fluid distribution in the flow passage, reduces the pressure drop, and significantly improves the drag reduction effect of the aircraft and improves the aerodynamic performance.

[0026] The application is characterized by the specific design and cooperation of the rotating turbine disc and the blade, the spiral and gradually expanding arrangement of the blade along the outer wall of the hub, the direct lateral throwing of the fluid directly hitting the head of the aircraft by the centrifugal force generated by rotation, the formation of a negative pressure space at the head, the direct reduction of the pressure load of the head and the thermal load of the high-speed aircraft, the effective relief of the aerodynamic heating problem in the high-speed aircraft such as the hypersonic aircraft, and the avoidance of the risk of material ablation and internal equipment damage; the spun vortex flow formed by the thrown fluid at the rear body of the aircraft, the laminarization of the flow on the surface of the aircraft body to some extent, the effective reduction of the surface friction resistance of the rear body, the significant reduction of the pressure difference resistance and friction resistance of the aircraft, the significant reduction of the thermal load of the head of the supersonic aircraft, the significant drag reduction effect, and the effective improvement of the aerodynamic performance of the aircraft.

[0027] The rotating head configuration of the application can be installed on the head of the existing aircraft or directly replace the original head of the aircraft, a large range of negative pressure area is generated at the head, and the pressure difference drag reduction effect is achieved; the spiral and gradually expanding arrangement of the several blades along the outer wall of the hub makes the spun vortex flow downstream wrap around the aircraft body, isolates the aircraft body from the high-speed incoming flow, and effectively reduces the friction resistance; the spun vortex flow may make the flow on the surface of the aircraft body laminar, and also cause laminar drag reduction, which can be widely used in aircrafts in the air, underwater and on the ground. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings described below only show some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0029] Figure 1 It is a structural schematic diagram of the application;

[0030] Figure 2 It is a schematic diagram of the concave arc and the rectangular coordinate system in the application;

[0031] Figure 3 It is a front view of the application;

[0032] Figure 4 It is a left view of the application;

[0033] Figure 5 It is a simulation streamline diagram of the rotating head configuration of the application;

[0034] Figure 6 It is a drag coefficient diagram of the head configuration of the application at Ma=0.3, and the positive rotation is a rotating mode diagram without the need of motor driving;

[0035] Figure 7 The resistance coefficient of the head configuration of the present application at Ma=0.7, in the positive rotation is the rotation mode without the need of motor driving;

[0036] Figure 8 The simulation pressure cloud map of the head configuration of the present application at Ma=1.2, without blade;

[0037] Figure 9 The simulation pressure cloud map of the head configuration of the present application at Ma=1.2, in the rotation;

[0038] Figure 10 The simulation pressure cloud map without blade;

[0039] Figure 11 The simulation pressure cloud map in the positive rotation;

[0040] Wherein, 1, hub head tip; 2, hub; 3, wheel disc matching surface; 4, blade leading edge surface; 5, blade trailing edge surface; 6, blade pressure surface; 7, blade suction surface. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0042] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0043] REFERENCE Figures 1-11 The present application provides a rotating head configuration of pressure difference and friction drag reduction of a vehicle, comprising:

[0044] A turbine disc body, the turbine disc body comprising an integrally formed hub head tip 1 and hub 2; the hub head tip 1 is located at the front end of the hub 2, and the rear end of the hub 2 is provided with a wheel disc matching surface 3;

[0045] Blades, a plurality of blades are provided, and the plurality of blades are installed on the outer wall of the hub 2 at equal intervals in the circumferential direction; the blades comprise a blade leading edge surface 4, a blade trailing edge surface 5, a blade pressure surface 6 and a blade suction surface 7, and the three-dimensional shape of the blades is formed by lofting a spatial curve; the blade leading edge surface 4 is arranged close to the hub head tip 1, and the blade trailing edge surface 5 is arranged close to the wheel disc matching surface 3; the blades adopt a lofting form combined with a spatial curve, so that the geometric shape of the blades on the windward surface can smoothly guide the airflow;

[0046] The hub 2 is a rotary body structure formed by an inner concave arc line rotation; a plurality of blades are arranged along the outer wall of the hub 2 in a spiral manner, the height of the blade and the distance between adjacent two blades are increased in turn along the spiral direction, and the increasing rate is flexibly adjustable, and the specific form can be determined according to the fluid dynamics requirements, covering linear, nonlinear or other increasing rules;

[0047] By the arrangement, compared with the conventional fixed head configuration, the head-on airflow can be laterally thrown out and vortexes are formed in the rear body, so that the friction resistance and the pressure difference resistance are effectively and significantly reduced, and the overall aerodynamic performance of the vehicle is improved.

[0048] The plurality of blades are arranged along the hub surface of the hub 2 at equal intervals in the circumferential direction, the height of the blade and the distance between adjacent two blades are increased in turn along the spiral direction, the height of the blade is small at the air inlet, the airflow can be quickly guided into the turbine disc, the deflection and separation of the airflow are reduced, then the height of the blade is gradually increased, the airflow keeps stable and uniform flow, the resistance and reverse flow are reduced, and the dynamic change requirement of high-speed airflow is met; meanwhile, with the increase of the blade height, the width of the flow channel is also increased, which effectively reduces the pressure drop in the flow channel, so that the airflow is more stable when passing through the blade, the sharp compression and turbulent flow of the airflow are reduced, the energy loss caused by the pressure drop is reduced, the fluid distribution in the flow channel is optimized, the pressure drop is reduced, the drag reduction effect of the vehicle is significantly improved, and the aerodynamic performance is improved.

[0049] The specific design and mutual cooperation of the turbine disc body and the blade in the rotating configuration, the spiral and gradual expansion arrangement of the blade along the outer wall of the hub 2, the centrifugal force generated by the rotation of the turbine disc directly throws the fluid directly hitting the head of the vehicle laterally, forms a negative pressure space in the head, directly reduces the pressure load of the head and the thermal load of the high-speed vehicle, and the negative pressure area can effectively alleviate the aerodynamic heating problem in the high-speed vehicle such as the hypersonic vehicle, avoids the risk of material ablation and internal equipment damage; the thrown fluid forms a rotating vortex in the rear body of the vehicle, to a certain extent, the surface flow of the vehicle body is laminarized, the surface friction resistance of the rear body is effectively reduced, so that the pressure difference resistance and the friction resistance of the vehicle are significantly reduced, for the supersonic vehicle, the compressed high-temperature gas encountered by the head is radially thrown out, the thermal load is also significantly reduced, a significant drag reduction effect is achieved, and the aerodynamic performance of the vehicle is effectively improved.

[0050] The rotating head configuration of the present application can be installed on the existing vehicle head or directly replace the original vehicle head, a large range of negative pressure area is generated in the head, so that the pressure difference drag reduction effect is achieved; the spiral and gradual expansion arrangement of the plurality of blades along the outer wall of the hub makes the downstream rotating vortex wrap around the vehicle body, so that the vehicle body is isolated from the high-speed airflow, and the friction resistance is effectively reduced; the rotating vortex can make the surface flow of the vehicle body laminar, and also cause laminar flow drag reduction, which can be widely used in vehicles in the air, underwater and on the ground.

[0051] Further optimization scheme, the hub head tip 1 is provided with a rounded corner, so that the airflow can smoothly transition when flowing through the hub head tip 1, reducing the turbulence and local high pressure caused by sharp corners, which can alleviate the aerodynamic heating (high-speed aircraft), to a certain extent, effectively reducing the opportunity to generate pressure difference.

[0052] Further optimization scheme, the wheel disc matching surface 3 is a plane, and the edge of the wheel disc matching surface 3 is integrally processed with the rear end edge of the hub 2, and the wheel disc matching surface 3 is used for connecting the shaft body;

[0053] The wheel disc matching surface 3 is a key surface for connecting the hub 2 and the rear body, and the wheel disc matching surface 3 is integrally processed through close contact with the edge of the hub surface of the hub 2, so as to ensure the rotation stability of the turbine disc.

[0054] Further optimization scheme, taking the center of the wheel disc matching surface 3 as the coordinate origin, the x direction, the y direction and the z direction form the coordinate axes respectively, and a rectangular coordinate system is established;

[0055] The wheel disc matching surface 3 is a plane where the y coordinate axis and the z coordinate axis are located, and the inner concave arc line is located in the plane where the x coordinate axis and the z coordinate axis are located; the two endpoints of the inner concave arc line are respectively set as A point and B point, the coordinate origin is set as O point, the distance from the O point to the B point is the radius r of the wheel disc matching surface, and the distance from the O point to the A point along the x axis is d;

[0056] The calculation formula of the inner concave arc line is z=r*tanhk*x+r, -d<x<0;

[0057] Wherein: define k as a shape factor, which represents the inclination degree of the inner concave arc line, 0.06<k<0.17; 0.75<r / d<1.3;

[0058] The hub 2 is a revolution body structure formed by rotating the inner concave arc line, and the hub surface of the hub 2 is stretched by rotating a hyperbolic tangent function curve, but is not limited to such mathematical expression, all curves (such as exponential curve, parabola, ellipse, etc.) meeting the arc line type change are within the protection scope;

[0059] So that the hub surface of the hub 2 has a specific curvature distribution, can effectively deflect the inflow direction of the fluid, and realizes the optimization of the fluid pressure gradient by reasonably selecting the curve parameters and the definition domain;

[0060] The present application utilizes the hyperbolic tangent function curve to rotate and stretch to form the hub surface of the hub 2, and adopts two rectangular surfaces to loft along the space curve to form the disc blade, and the wheel disc matching surface is combined to realize the rotation purpose of the turbine disc.

[0061] Further optimization scheme, the shape of the blade leading edge surface 4 is rectangular, the blade leading edge surface 4 is parallel to the plane where the x coordinate axis and the z coordinate axis are located; the starting position of the blade leading edge surface 4 is moved (15%-50%) d along the positive direction of the x axis from the hub head tip 1;

[0062] The blade leading edge surface 4 needs to bear the airflow load, and within a certain thickness range, the bending stiffness of the rectangular section is relatively balanced, which can effectively disperse the pressure and shear force generated by the airflow and avoid local overload or buckling;

[0063] The length of the blade leading edge surface 4 is h1, 0.04<h1 / r<0.12, and the width of the blade leading edge surface 4 is d1. According to different aircraft application scenarios, such as missiles and carrier rockets, the value range of the related parameter d1 is between 0.5 and 1.5 mm.

[0064] Further optimization scheme, the shape of the blade trailing edge surface 5 is rectangular, the length of the blade trailing edge surface 5 is h2, 0.15<h2 / r<0.4, and the width of the blade trailing edge surface 5 is d2, the value range of d2 is 0.5-1.5 mm; in this embodiment, the length h2 of the blade trailing edge surface 5 is preferably 55 mm, and the width d2 is preferably 1 mm.

[0065] Further optimization scheme, the angle between the blade trailing edge surface 5 and the plane where the x coordinate axis and the z coordinate axis are located is α, 40°<α<60°; in this embodiment, the angle α is preferably 50°.

[0066] Further optimization scheme, the number of blades is not less than six; in this embodiment, the number of blades is preferably nine.

[0067] Further optimization scheme, the blade suction surface 7 is a smooth concave surface, and the blade pressure surface 6 is a smooth convex surface, so that the airflow can flow along the surface of the blade when passing through, forming a stable airflow laminar flow region, thereby reducing the friction between the surface of the blade and the airflow and reducing the frictional resistance.

[0068] Further optimization scheme, the radius of the round corner is 4-10 mm.

[0069] Figures 10-11 It can be seen that the simulation pressure cloud map of the head configuration of the present application at Ma=1.2 in the forward rotation mode, the drag reduction rate can reach 57%; specifically, Figure 10 Without the blade, there is a significant shock wave near the head configuration, and the forward rotation of the blade can effectively weaken this shock wave, thereby significantly reducing the overall drag coefficient.

[0070] In the description of the present application, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are terms of convenience which refer to the orientation of the application as shown in the drawings and as such are used for purposes of description only. They do not necessarily imply or require that the device or element assume a particular spatial orientation in its use or operation, unless expressly so described.

[0071] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to enumerate all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A rotating head configuration for aircraft pressure difference and friction drag reduction, characterized in that: Comprising: A turbine disk body, the turbine disk body includes an integrally formed hub head tip (1) and a hub (2); the hub head tip (1) is located at the front end of the hub (2), and a disk mating surface (3) is provided at the rear end of the hub (2); Blades, there are several blades, and several of the blades are circumferentially and equally spaced on the outer wall of the hub (2); the blades include a blade leading edge surface (4), a blade trailing edge surface (5), a blade pressure surface (6) and a blade suction surface (7); the blade leading edge surface (4) is arranged close to the hub head tip (1), and the blade trailing edge surface (5) is arranged close to the disk mating surface (3); Wherein, the hub (2) is a rotary body structure formed by the rotation of an inward concave arc; several of the blades are arranged in a spiral and gradually expanding manner along the outer wall of the hub (2), and the height of the blades and the spacing between adjacent two blades both increase sequentially along the spiral direction; taking the center of the disk mating surface (3) as the coordinate origin, the x-direction, y-direction and z-direction respectively form coordinate axes to establish a rectangular coordinate system; The disk mating surface (3) is the plane where the y-axis and z-axis are located, and the inward concave arc is located in the plane where the x-axis and z-axis are located; the two end points of the inward concave arc are respectively set as point A and point B, setting the coordinate origin as point O, the distance from point O to point B is the radius r of the disk mating surface, and the distance from point O to point A along the x-axis is d; The calculation formula of the inward concave arc is z = r*tanh(k*x)+r, (-d < x < 0); Where: k is defined as a shape factor, representing the inclination degree of the inward concave arc, 0.06 < k < 0.17; 0.75 < r / d < 1.

3.

2. The rotating head configuration for aircraft pressure difference and friction drag reduction according to claim 1, characterized in that: The hub head tip (1) is provided with a rounded corner.

3. The rotating head configuration for aircraft pressure difference and friction drag reduction according to claim 1, characterized in that: The disk mating surface (3) is a plane, and the edge of the disk mating surface (3) is integrally processed with the rear end edge of the hub (2), and the disk mating surface (3) is used to connect the shaft body.

4. The rotating head configuration for aircraft pressure difference and friction drag reduction according to claim 1, characterized in that: The shape of the blade leading edge surface (4) is rectangular, and the blade leading edge surface (4) is arranged parallel to the plane where the x-axis and z-axis are located; The length of the blade leading edge surface (4) is h1, 0.04 < h1 / r < 0.

12.

5. The rotating head configuration for aircraft pressure difference and friction drag reduction according to claim 1, characterized in that: The shape of the blade trailing edge surface (5) is rectangular, the length of the blade trailing edge surface (5) is h2, 0.15 < h2 / r < 0.4, and the width of the blade trailing edge surface (5) is d2, and the value range of d2 is 0.5 to 1.5 mm.

6. The rotating head configuration for aircraft pressure difference and friction drag reduction according to claim 1, characterized in that: The included angle between the blade trailing edge surface (5) and the plane where the x-axis and z-axis are located is α, 40° < α < 60°.

7. The rotating head configuration for aircraft pressure difference and friction drag reduction according to claim 1, characterized in that: The number of the blades is not less than six.

8. The rotating head configuration for aircraft pressure difference and friction drag reduction according to claim 1, characterized in that: The blade suction surface (7) is an inward concave surface, and the blade pressure surface (6) is an outward convex surface.

9. The rotating head configuration for aircraft pressure difference and friction drag reduction according to claim 2, characterized in that: The radius of the rounded corner is 4 mm to 10 mm.

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