Efficient low-noise rotor shape optimization design method and equipment for tilting multi-rotor aircraft

Abstract

The invention discloses an efficient low-noise rotor shape optimization design method and device for a tilting multi-rotor aircraft, and relates to the field of tilting multi-rotor aircraft design. The method comprises the steps that a rotor optimization target is formulated according to the design requirement of the tilting multi-rotor aircraft; parameterizing the original blades, and constructing to obtain a plurality of tilting multi-rotor aircraft models; a target tilting multi-rotor aircraft model is selected, the aerodynamic performance parameters and the aerodynamic noise level of the target tilting multi-rotor aircraft model under multi-rotor aerodynamic interference are obtained through a full-aircraft flow field solving and aerodynamic noise evaluation method, and then target blades are output according to rotor comprehensive performance design evaluation indexes; according to the method, the influence of complex aerodynamic interference among the blades of the multi-rotor aircraft is considered, the accurate rotor comprehensive performance design evaluation index is obtained, the target tilting multi-rotor aircraft model exceeding the rotor comprehensive performance design evaluation index is selected as the target blade, and the target blade closer to the actual aerodynamic performance is obtained.

Description

Technical Field

[0001] The present application relates to the field of tilt-rotor multi-rotor aircraft design, and in particular to a method and device for optimizing the design of a high-efficiency and low-noise rotor shape of a tilt-rotor multi-rotor aircraft. Background Art

[0002] Tilt-rotor multi-rotor aircraft is a hot topic in the field of tilt-rotor aircraft at home and abroad. The aerodynamic shape design of the rotor of the tilt-rotor multi-rotor aircraft is crucial. The aerodynamic performance of the rotor directly determines the overall aerodynamic performance index of the tilt-rotor multi-rotor aircraft. In order to improve the aerodynamic performance of the rotor, the current advanced rotor design mostly adopts the three-dimensional combined blade tip design concept, that is, the rotor blade tip with forward / backward sweep and downward reverse characteristics is used to reduce the blade tip vortex strength, improve the pressure distribution on the rotor surface, and improve the flight performance of the whole aircraft.

[0003] At present, the optimization design of conventional helicopter rotor shape is mainly based on the momentum blade element theory and lift line method to carry out theoretical design of rotor negative twist distribution, chord length distribution and airfoil distribution. The expected rotor blade aerodynamic performance is obtained through theoretical formulas, and then the performance parameters of the rotor are verified through wind tunnel tests. The above theoretical method can quickly estimate the rotor design performance, but the estimation accuracy of the increasingly complex three-dimensional rotor aerodynamic performance is insufficient, and it cannot take into account the complex aerodynamic interference phenomenon of the tilt-rotor multi-rotor aircraft, resulting in a large gap between the theoretically designed tilt-rotor performance and the actual aerodynamic performance. Summary of the invention

[0004] The purpose of this application is to provide a method and device for optimizing the rotor shape of a tilt-rotor multi-rotor aircraft with high efficiency and low noise, which can obtain accurate rotor comprehensive performance design evaluation indicators, and thus obtain target blades that are closer to actual aerodynamic performance.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a method for optimizing the rotor shape of a tilt-rotor aircraft with high efficiency and low noise, the method comprising: formulating a rotor optimization target according to the design requirements of the tilt-rotor aircraft; the optimization target is a rotor comprehensive performance design evaluation index; the rotor comprehensive performance design evaluation index is obtained by weighting the aerodynamic performance and noise level of the tilt-rotor aircraft; parameterizing the original blades, and constructing multiple tilt-rotor aircraft models; selecting one of the multiple tilt-rotor aircraft models as a target tilt-rotor aircraft model; and according to the target tilt-rotor aircraft model, The methods of whole-aircraft flow field solution and aerodynamic noise evaluation are used to obtain the aerodynamic performance parameters and aerodynamic noise level of the target tilt-multirotor model under multi-rotor aerodynamic interference, and the rotor comprehensive performance design evaluation index of the target tilt-multirotor model is calculated; it is judged whether the rotor comprehensive performance design evaluation index of the target tilt-multirotor model is greater than the target threshold. If so, the blade parameters of the target tilt-multirotor model are output as the target blade parameters; if not, it returns to "select one of the multiple tilt-multirotor models as the target tilt-multirotor model".

[0007] In a second aspect, the present application provides a computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the above-described methods for optimizing the rotor shape of a tilt-rotor multi-rotor aircraft with high efficiency and low noise.

[0008] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0009] The present application formulates rotor optimization targets according to the design requirements of the tilt-rotor multi-rotor aircraft; parameterizes the original blades and constructs multiple tilt-rotor multi-rotor aircraft models; selects a target tilt-rotor multi-rotor aircraft model, and uses the whole-aircraft flow field solution and aerodynamic noise evaluation methods to respectively obtain the aerodynamic performance parameters and aerodynamic noise level of the target tilt-rotor multi-rotor aircraft model under the multi-rotor aerodynamic interference, and calculates the rotor comprehensive performance design evaluation index of the target tilt-rotor multi-rotor aircraft model; the present application takes into account the influence of the complex aerodynamic interference between the multi-rotor aircraft blades, obtains accurate rotor comprehensive performance design evaluation indexes, and selects the target tilt-rotor multi-rotor aircraft model that exceeds the rotor comprehensive performance design evaluation index as the target blade, thereby obtaining a target blade that is closer to the actual aerodynamic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1 A schematic flow chart of a method for optimizing the rotor shape of a tilt-rotor aircraft with high efficiency and low noise provided in an embodiment of the present application.

[0012] Figure 2 A top view of the tilt-quadrotor model provided in an embodiment of the present application.

[0013] Figure 3 A front view of the tilt-quadrotor model provided in an embodiment of the present application.

[0014] Figure 4 A side view of the tilt-quadrotor model provided in an embodiment of the present application.

[0015] Figure 5 Schematic diagram of the calculation grid of the tilt-quadrotor aircraft in helicopter mode provided in an embodiment of the present application.

[0016] Figure 6 Schematic diagram of the computational grid for a tilt-quadrotor aircraft in fixed-wing mode provided in an embodiment of the present application.

[0017] Figure 7 A schematic diagram of the xy plane shape parameterization and design variables of the blade tip provided in an embodiment of the present application.

[0018] Figure 8 A schematic diagram of the xz plane shape parameterization and design variables of the blade tip provided in an embodiment of the present application.

[0019] Fig. 9 This is a diagram of the optimization results of the front rotor tip plane shape provided in an embodiment of the present application.

[0020] Fig.10 This is a diagram of the optimization results of the rotor tip plane shape provided in an embodiment of the present application.

[0021] Fig.11 This is a pressure cloud diagram of the upper surface of the original blade of the front rotor in the helicopter mode provided in an embodiment of the present application.

[0022] Fig.12 This is a pressure cloud diagram of the upper surface of the front rotor blade in the helicopter mode provided in an embodiment of the present application.

[0023] Fig.13 This is a pressure cloud diagram of the upper surface of the original blade of the rear rotor in the helicopter mode provided in an embodiment of the present application.

[0024] Fig.14 This is a pressure cloud diagram of the upper surface of the rear rotor blade in the helicopter mode provided in an embodiment of the present application.

[0025] Fig.15A comparison chart of the front rotor hovering efficiency optimization results provided in the embodiments of the present application.

[0026] Fig.16 A comparison chart of the optimization results of the rear rotor hovering efficiency provided in the embodiments of the present application.

[0027] Fig.17 This is a pressure cloud diagram of the upper surface of the front rotor blade in the fixed-wing mode provided in an embodiment of the present application.

[0028] Fig.18 This is a pressure cloud diagram of the upper surface of the front rotor blade in the fixed-wing mode provided in an embodiment of the present application.

[0029] Fig.19 This is a pressure cloud diagram of the upper surface of the initial blade of the rear rotor in the fixed-wing mode provided in an embodiment of the present application.

[0030] Fig. 20 This is a pressure cloud diagram of the upper surface of the rear rotor blade in the fixed-wing mode provided in an embodiment of the present application.

[0031] Fig.21 Schematic diagram of the time history of blade sound pressure optimization and initial blade sound pressure at the observation point in the helicopter mode provided in an embodiment of the present application.

[0032] Fig. 22 A schematic diagram comparing the horizontal plane propagation characteristics of the optimized blade and the initial blade in the helicopter mode provided in an embodiment of the present application.

[0033] Fig.23 Schematic diagram comparing the sound pressure levels of the optimized blade and the initial blade at the observation point in the fixed-wing mode provided in an embodiment of the present application.

[0034] Fig.24 Schematic diagram comparing the horizontal plane propagation characteristics of the optimized blade and the initial blade in the fixed-wing mode provided in an embodiment of the present application.

[0035] Fig.25 The present invention is a schematic diagram of the structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0038] Embodiment 1, as Figure 1 As shown, this embodiment provides a method for optimizing the shape of a high-efficiency and low-noise rotor of a tilt-rotor multi-rotor aircraft, the method comprising:

[0039] S1. Formulate rotor optimization targets according to the design requirements of the tilt-rotor multi-rotor aircraft; the optimization targets are rotor comprehensive performance design evaluation indicators; the rotor comprehensive performance design evaluation indicators are obtained by weighting the aerodynamic performance and noise level of the tilt-rotor multi-rotor aircraft.

[0040] Furthermore, the calculation formula of the rotor comprehensive performance design evaluation index is as follows:

[0041] P = a*FM + b*η + 1 / SPL;

[0042] SPL = (a * SPL 1 +b*SPL 2 ) / 2;

[0043]

[0044] η=μ n ×C T / C Q ;

[0045] Where P is the rotor comprehensive performance design evaluation index, FM is the hovering efficiency of the tilt-rotor multi-rotor aircraft in helicopter mode, η is the cruising efficiency of the tilt-rotor multi-rotor aircraft in fixed-wing mode, SPL is the aerodynamic noise level of the tilt-rotor multi-rotor aircraft, SPL1 is the noise level of the tilt-rotor multi-rotor aircraft in fixed-wing mode (forward flight state), SPL2 is the noise level of the tilt-rotor multi-rotor aircraft in helicopter mode (hovering state), μ n is the advance ratio of the tiltrotor, C T is the pull coefficient of the tiltrotor, C Q is the power coefficient of the tiltrotor, a and b are weight coefficients.

[0046] Further, a=0.6; b=0.4.

[0047] In actual application, each basic blade grid and fuselage wing grid are obtained through the aerodynamic layout parameters of each basic blade (sample point) and the fuselage wing parameters; the CFD method based on the RANS master control equation is used to solve the flow field of the whole aircraft to obtain the aerodynamic performance parameters; the aerodynamic noise is evaluated with the aerodynamic information as input to obtain the noise level of the whole aircraft; and the objective function value of the individual population is further obtained.

[0048] The tilt-quadrotor model used is as follows: Figure 2 , Figure 3 and Figure 4As shown, the main parameters of the fuselage are shown in Table 1:

[0049] Table 1 Main parameters of tilt-quadrotor aircraft

[0050] parameter Numeric Captain / m 4.7 Machine height / m 1.3 Front wingspan / m 3.0 Rear wingspan / m 3.8 Front wing installation angle / ° 3.3 Rear wing installation angle / ° 3.0 Wing sweep angle / ° 0 Wing dihedral angle / ° 0 Maximum take-off weight / kg 700 Wing airfoil CLARKYM15

[0051] The main parameters of the tilt-quadrotor rotor are shown in Table 2:

[0052] Table 2 Main parameters of the tilt-quadrotor rotor

[0053] parameter Numeric Rotor airfoil XV-15 Rotor Airfoil Rotor radius / m 1.0 Rotor undercutting 10％ Tip speed / m / s 210 Number of propeller blades / rotor / blade 3 Rotor longitudinal spacing / m 1.9 Rotor vertical spacing / m 0.25 Rotor lateral spacing / m 0.4

[0054] The computational grids for the hovering state and forward flight state of the tilt-quadrotor aircraft are as follows: Figure 5 and Figure 6 shown.

[0055] Among them, the noise level of the tilt-rotor multi-rotor aircraft is the weighted noise level of the helicopter mode and the fixed-wing mode: in the helicopter mode, the sound radiation is strongest directly behind the fuselage, so the observation point is selected as the point 10R away from the center of the nose on the tail side of the fuselage plane in the forward direction; in the fixed-wing mode, the sound radiation is strongest directly in front of the fuselage, so the observation point is selected as the point 10R away from the center of the hub directly in front of the fuselage plane in the forward direction.

[0056] S2. Parameterize the original blades and construct multiple tilt-rotor multi-rotor aircraft models.

[0057] Step S2 specifically includes:

[0058] S21. Parameterize the original blade to obtain a design parameter range of blade feature points; the blade feature points include: forward-swept feature points, backward-swept feature points and downward-reverse feature points.

[0059] Step S21 specifically includes:

[0060] Step S211: Design the aerodynamic layout parameters of the original blade model in the forward-swept-backward-inverted manner to determine the blade feature points.

[0061] Step S212: parameterize the blade feature points to obtain the design parameter range of the blade feature points.

[0062] In the actual application process, XV-15 is first selected as the reference blade, and four blade shape parameter variables are selected for optimization design. The design parameter diagram is shown in Figure 7 and Figure 8As shown in the figure, R represents the rotor radius, c represents the reference chord length, h represents the reference airfoil height, x represents the spanwise position, y represents the chordwise position, and z represents the airfoil height. The dotted line in the figure is a quarter chord line. P1, P2, and P3 are three points on the leading edge of the blade plane shape. var1, var2, var3, and var4 are the four design parameters in the optimization process. The section chord length from the root of the rotor blade to 0.80R in the spanwise direction is the reference chord length.

[0063] The leading edge shape between points P1 and P2 is parameterized, and the curve between points P1 and P2 is a cubic function curve; point P2 is located at the leading edge blade tip, and the leading edge shape curve between P2 and P3 is a parabola; the trailing edge shapes of the blades at points P1 and P2 are similar to the leading edge shape, and a straight line transition is used between the trailing edges of points P2 and P3 to achieve a smooth transition deformation effect of the blade tip shape.

[0064] 0.8R<x≤var 1 The leading edge of the time:

[0065] y=a 1 (x-0.8R) 3 +b 1 (x-0.8R) 2 +c;

[0066]

[0067] var 1 Leading edge when <x<R:

[0068]

[0069] The ranges of the four design parameters var1, var2, var3 and var4 are:

[0070]

[0071] S22. Select different parameters within the design parameter range of the blade characteristic points to construct multiple basic blade types.

[0072] Step S22 specifically includes:

[0073] Step S221. Within the design parameter range of the blade characteristic points, different parameters are selected using the Latin hypercube method according to the number of rotors, and multiple basic blade types are constructed based on the different parameters.

[0074] After step S22, the method further includes: performing preliminary optimization on multiple basic propeller types using a BP neural network approximate model optimized based on a genetic algorithm.

[0075] In the actual application process, the sample points are encoded, selected, and cross-mutated through the optimization method of the combination of the BP neural network approximate model and the genetic algorithm. Encoding refers to encoding the curve expression of the basic blade obtained. Since the genetic algorithm cannot directly process the parameters of the problem space, the problem to be solved must be expressed as a chromosome or individual in the genetic space through encoding. In other words, the encoding process is to map the phenotype (the curve expression of the basic blade) to the genotype. The combination of BP neural network and genetic algorithm is an intelligent optimization strategy, in which the genetic algorithm is used to optimize the parameters of the BP neural network to improve the learning ability and generalization performance of the network. This method combines the powerful function approximation ability of the BP neural network and the advantages of the genetic algorithm in global search and optimization. Through the iterative search and fitness evaluation of the genetic algorithm, a better network parameter configuration can be found, thereby improving the training efficiency and prediction accuracy of the neural network.

[0076] S23. Construct multiple tilt-rotor multi-rotor aircraft models based on multiple basic propeller types.

[0077] S3. Select one of the multiple tilt-rotor multi-rotor aircraft models as a target tilt-rotor multi-rotor aircraft model.

[0078] S4. According to the target tilt-multi-rotor aircraft model, the aerodynamic performance parameters and aerodynamic noise level of the target tilt-multi-rotor aircraft model under the multi-rotor aerodynamic interference are obtained by using the whole-aircraft flow field solution and aerodynamic noise evaluation methods, and the rotor comprehensive performance design evaluation index of the target tilt-multi-rotor aircraft model is calculated.

[0079] Furthermore, the whole machine flow field solution adopts a CFD method based on the RANS master control equation.

[0080] Step S4 specifically includes:

[0081] S41. According to the fuselage-wing parameters and the aerodynamic layout parameters of the multiple blades in the target tilt-multirotor model, the fuselage-wing grid and the blade grid of the multi-rotor target tilt-multirotor model are respectively constructed.

[0082] S42. Solve the flow field of the entire aircraft based on the fuselage wing grid and blade grid of the target tilt-multi-rotor aircraft model to obtain the aerodynamic performance parameters of the target tilt-multi-rotor aircraft model under the multi-rotor aerodynamic interference.

[0083] S43. Perform an aerodynamic noise evaluation on the target tilt-multi-rotor aircraft model to obtain the aerodynamic noise level of the target tilt-multi-rotor aircraft model under multi-rotor aerodynamic interference.

[0084] S44. Based on the aerodynamic performance parameters and aerodynamic noise level, the rotor comprehensive performance design evaluation index of the target tilt-multi-rotor aircraft model is calculated.

[0085] S5. Determine whether the rotor comprehensive performance design evaluation index of the target tilt-multirotor model is greater than the target threshold. If so, output the blade parameters of the target tilt-multirotor model as the target blade parameters; if not, return to step S3 "select one from multiple tilt-multirotor models as the target tilt-multirotor model".

[0086] In actual application, the rotor optimization results of the tilt-quadrotor aircraft considering the aerodynamic interference environment of the whole aircraft are as follows: Fig. 9 and Fig.10 As shown in the figure, the forward sweep angle of the front rotor is 12.3°, the sweep angle is 40°, the downward reversal angle is 5.3°, and the downward reversal and sweep positions start from 0.95R; the forward sweep angle of the rear rotor is 8.3°, the sweep angle is 25.4°, the downward reversal angle is 13.2°, and the downward reversal and sweep positions start from 0.9R. It can be seen that the forward sweep angle and the sweep angle of the optimized front rotor blade are greater than those of the rear rotor, while the downward reversal angle of the rear rotor is greater than that of the front rotor. This is because in the forward flight state, the forward sweep-backward sweep angle improves the cruising efficiency of the front rotor more than that of the rear rotor, while the downward reversal angle improves the cruising efficiency of the rear rotor more than that of the front rotor, and the forward sweep-backward sweep-downward reversal angle has limited improvement on the hovering efficiency of the front / rear rotor in the hovering state.

[0087] The comparative analysis results of the aerodynamic and noise characteristics of the optimized rotor in this embodiment are as follows:

[0088] First, in the hovering state (in helicopter mode), optimize the pressure cloud diagram on the upper surface of the front / rear rotor. Fig.11 , Fig.12 , Fig.13 and Fig.14 As shown in the figure, it can be seen that the negative pressure peak area on the upper surface of the optimized front / rear rotor blades is significantly smaller than that of the initial front / rear blades, and the negative pressure peak area at the tip of the blade is also significantly reduced and shrinks inside the blade. This will effectively reduce the aerodynamic drag at the blade tip. In addition, the reduction of the negative pressure peak of the blade helps to reduce the rotor load noise.

[0089] Second, the comparison of front / rear rotor hovering efficiency optimization results is shown in the figure below: Fig.15 and Fig.16 As shown in the figure, it can be seen that the performance of the optimized front / rear rotor hovering state is improved in the entire pulling force range compared with the initial blades. The front rotor hovering efficiency is improved by up to 1.5%; the rear rotor hovering efficiency is improved by up to 1.0%. The reason why the front rotor is improved more significantly is that the front rotor is in the downwash range of the rear rotor, and the working flow field is more complex. The use of high-performance blade tip shape can significantly improve its hovering performance. The rear rotor is less affected by the front rotor, and the blade tip Mach number is not large, so the hovering performance is improved less.

[0090] Table 3 shows the aerodynamic efficiency comparison of the initial blade and the optimized blade in the cruise state (360km / h). It can be seen that the cruise efficiency of the front rotor is improved by 10.3%, and the cruise efficiency of the rear rotor is improved by 8.9%. This is because in the forward flight state (fixed-wing mode), the rear rotor is almost completely in the front rotor wake area, and the front rotor wake has a greater impact on the rear rotor than the rotor tip shape, and the front rotor working flow field is relatively simple, so the cruise efficiency is improved more than the rear rotor.

[0091] Table 3 Comparison of cruise efficiency between initial blades and optimized blades

[0092] Serial number Front rotor cruise efficiency Rear rotor cruise efficiency Initial blade 0.4535 0.5702 Optimized propeller blades 0.4992 0.6213

[0093] Fourth, the optimization results of the pressure coefficient cloud diagram on the upper surface of the front / rear rotor in forward flight are as follows: Fig.17 , Fig.18 , Fig.19 and Fig. 20 As shown in the figure, it can be seen that the negative pressure peak area on the upper surface of the optimized front / rear rotor blades is significantly smaller than that of the initial front / rear blades. The reduction in the negative pressure peak area helps to reduce the aerodynamic drag of the blades, further reduce the torque, and improve the cruise efficiency. In addition, the reduction in the negative pressure intensity of the blades helps to reduce the rotor load noise.

[0094] Fifth, the sound pressure time history of the optimized rotor blade and the initial blade hovering state at the observation point is compared as follows Fig.21 As shown, it can be seen that the peak value of the initial blade at the observation point is 4.71Pa, while the peak value of the optimized blade at the same position is 3.74Pa. The negative pressure peak of the optimized blade is reduced by 20.5%. The reduction in the sound pressure level intensity of the optimized blade at the above observation point shows that the aerodynamic noise control level of the optimized blade is better than that of the initial blade.

[0095] Sixth, the propagation characteristics of the hovering state optimized blade and the initial blade in the horizontal plane are compared as follows: Fig. 22 As shown, it can be seen that the maximum sound pressure levels of the optimized blades and the initial blades appear at the rear of the fuselage horizontal plane, while the sound pressure level intensity of the optimized blades is generally lower than that of the initial blades within the horizontal range of the fuselage, among which the sound radiation intensity decreases the most in the middle and rear part of the fuselage, and the maximum noise decibel can be reduced by 1.8db.

[0096] Seventh, the sound pressure time history of the optimized blade and the initial blade in the forward flight state at the observation point 10R (R is the rotor radius) in the horizontal plane of the fuselage directly in front of the nose is compared as follows Fig.23 As shown, it can be seen that the negative pressure peak of the initial blade is 5.306Pa, while the negative pressure peak of the optimized blade at the same position is 4.149Pa. The negative pressure peak of the optimized blade is 21.8% lower than that of the initial blade, which indicates that the aerodynamic noise control level of the optimized blade in the forward flight state is better than that of the initial blade.

[0097] Eighth, the forward flight state optimization blade and the initial blade horizontal plane propagation characteristics are as follows Fig.24 As shown, it can be seen that the maximum sound pressure level occurs in front of the nose. The sound pressure level intensity of the optimized blades is generally lower than that of the initial blades within the horizontal range of the fuselage. The largest drop is in the middle and rear part of the fuselage, where the sound pressure level can be reduced by up to 2.2db.

[0098] The technical effects of this application are as follows:

[0099] First, this application formulates rotor optimization goals according to the design requirements of the tilt-rotor multi-rotor aircraft; parameterizes the original blades and constructs multiple tilt-rotor multi-rotor aircraft models; selects a target tilt-rotor multi-rotor aircraft model, and uses the whole-aircraft flow field solution and aerodynamic noise evaluation methods to obtain the aerodynamic performance parameters and aerodynamic noise level of the target tilt-rotor multi-rotor aircraft model under multi-rotor aerodynamic interference, and calculates the rotor comprehensive performance design evaluation index of the target tilt-rotor multi-rotor aircraft model; this application takes into account the influence of complex aerodynamic interference between multi-rotor aircraft blades, obtains accurate rotor comprehensive performance design evaluation indexes, and selects the blade parameters of the target tilt-rotor multi-rotor aircraft model that exceed the rotor comprehensive performance design evaluation index as the target blade parameter output, thereby obtaining target blade parameters that are closer to the actual aerodynamic performance.

[0100] Secondly, this application carries out collaborative optimization of the rotor noise / aerodynamic characteristics and multi-flight state performance under the aerodynamic interference environment of the tilt-rotor multi-rotor aircraft. The optimization target can be dynamically adjusted through weight factors according to the application scenario of the tilt-rotor multi-rotor aircraft. The proxy model method based on Latin hypercube and BP neural network can effectively reduce CFD calculation examples and improve calculation efficiency while ensuring calculation accuracy. At the same time, a combined optimization algorithm combining proxy model and genetic algorithm is adopted to solve the complex optimal numerical solution problems of multiple parameters, multiple design variables and multiple choices in the process of optimizing the rotor aerodynamic shape. It promotes the application of global optimization algorithms based on proxy models and genetic algorithms to complex engineering problems, and has important practical engineering value.

[0101] Embodiment 2, the present application also provides a computer device, which may be a server or a terminal, and its internal structure diagram may be as follows: Fig.25As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store video tag processing data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the above-mentioned method is implemented.

[0102] Those skilled in the art will understand that Fig.25 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0103] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0104] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for optimizing the shape of a high-efficiency and low-noise rotor for a tilt-multi-rotor aircraft, characterized in that: The tilt-rotor multi-rotor aircraft high-efficiency and low-noise rotor shape optimization design method comprises: Formulate a rotor optimization target according to the design requirements of the tilt-rotor multi-rotor aircraft; the optimization target is a rotor comprehensive performance design evaluation index; the rotor comprehensive performance design evaluation index is obtained by weighting the aerodynamic performance and noise level of the tilt-rotor multi-rotor aircraft; The original blades are parameterized and multiple tilt-rotor multi-rotor aircraft models are constructed; Selecting one of the multiple tilt-rotor multi-rotor aircraft models as a target tilt-rotor multi-rotor aircraft model; According to the target tilt-multi-rotor aircraft model, the aerodynamic performance parameters and aerodynamic noise level of the target tilt-multi-rotor aircraft model under the multi-rotor aerodynamic interference are obtained by using the whole-aircraft flow field solution and aerodynamic noise evaluation methods, and the rotor comprehensive performance design evaluation index of the target tilt-multi-rotor aircraft model is calculated; Determine whether the rotor comprehensive performance design evaluation index of the target tilt-multirotor model is greater than the target threshold. If so, output the blade parameters of the target tilt-multirotor model as the target blade parameters; if not, return to "select one of multiple tilt-multirotor models as the target tilt-multirotor model".

2. The method for optimizing the shape of a high-efficiency and low-noise rotor of a tilt-rotor aircraft according to claim 1, characterized in that: The original blades are parameterized and multiple tilt-rotor multi-rotor models are constructed, including: Parameterizing the original blade to obtain a design parameter range of blade feature points; the blade feature points include: a forward-swept feature point, a backward-swept feature point, and a downward-reverse feature point; Select different parameters within the design parameter range of the blade characteristic points to construct multiple basic blade types; Multiple tilt-rotor multi-rotor aircraft models are constructed based on multiple basic propeller types.

3. The method for optimizing the shape of a high-efficiency and low-noise rotor of a tilt-rotor aircraft according to claim 2, characterized in that: The original blade is parameterized to obtain the design parameter range of the blade feature points, including: The aerodynamic layout parameters of the original blade model are designed to be swept forward, swept back and reversed downward, and the characteristic points of the blade are determined; The blade feature points are parameterized to obtain the design parameter range of the blade feature points.

4. The method for optimizing the shape of a high-efficiency and low-noise rotor of a tilt-multi-rotor aircraft according to claim 2, characterized in that: Different parameters are selected within the design parameter range of the blade characteristic points to construct multiple basic propeller types, including: Within the design parameter range of the blade characteristic points, different parameters are selected according to the number of rotors using the Latin hypercube method, and multiple basic blade types are constructed based on different parameters.

5. The method for optimizing the shape of a high-efficiency and low-noise rotor of a tilt-rotor aircraft according to claim 2, characterized in that: Different parameters are selected within the design parameter range of the blade characteristic points to construct multiple basic propeller types, and then it also includes: using a BP neural network approximate model based on genetic algorithm optimization to preliminarily optimize the multiple basic propeller types.

6. The method for optimizing the shape of a high-efficiency and low-noise rotor of a tilt-multi-rotor aircraft according to claim 1, characterized in that: According to the target tilt-multi-rotor aircraft model, the aerodynamic performance parameters and aerodynamic noise level of the target tilt-multi-rotor aircraft model are obtained by using the full-aircraft flow field solution and aerodynamic noise evaluation methods, and the rotor comprehensive performance design evaluation indicators of the target tilt-multi-rotor aircraft model are calculated, including: According to the fuselage-wing parameters and aerodynamic layout parameters of multiple blades in the target tilt-multi-rotor model, the fuselage-wing grid and blade grid of the multi-rotor target tilt-multi-rotor model are respectively constructed; The whole-machine flow field is solved according to the fuselage, wing and blade grids of the target tilt-multi-rotor aircraft model, and the aerodynamic performance parameters of the target tilt-multi-rotor aircraft model under the multi-rotor aerodynamic interference are obtained; The aerodynamic noise of the target tilt-multi-rotor aircraft model is evaluated to obtain the aerodynamic noise level of the target tilt-multi-rotor aircraft model under the multi-rotor aerodynamic interference; The rotor comprehensive performance design evaluation index of the target tilt-multi-rotor aircraft model is calculated based on the aerodynamic performance parameters and aerodynamic noise levels.

7. The method for optimizing the shape of a high-efficiency and low-noise rotor of a tilt-multi-rotor aircraft according to claim 1, characterized in that: The calculation formula of the rotor comprehensive performance design evaluation index is as follows: P = a*FM + b*η + 1 / SPL; SPL = (a*SPL1+b*SPL2) / 2; h=m n ×C T / C Q ; Where P is the rotor comprehensive performance design evaluation index, FM is the hovering efficiency of the tilt-rotor multi-rotor aircraft in helicopter mode, η is the cruising efficiency of the tilt-rotor multi-rotor aircraft in fixed-wing mode, SPL is the aerodynamic noise level of the tilt-rotor multi-rotor aircraft, SPL1 is the noise level of the tilt-rotor multi-rotor aircraft in fixed-wing mode, SPL2 is the noise level of the tilt-rotor multi-rotor aircraft in helicopter mode, μ n is the advance ratio of the tiltrotor, C T is the pull coefficient of the tiltrotor, C Q is the power coefficient of the tiltrotor, a and b are weight coefficients.

8. The method for optimizing the shape of a high-efficiency and low-noise rotor of a tilt-multi-rotor aircraft according to claim 7, characterized in that: a=0.6; b=0.

4.

9. The method for optimizing the shape of a high-efficiency and low-noise rotor of a tilt-multi-rotor aircraft according to claim 1, characterized in that: The whole machine flow field solution adopts a CFD method based on the RANS master control equation.

10. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for optimizing the rotor shape of a tilt-rotor aircraft with high efficiency and low noise as described in any one of claims 1 to 9.

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