Aerodynamic characteristic analysis method considering interference of tail rotor of rotorcraft body

Abstract

The invention belongs to the technical field of aerodynamic design analysis of helicopters, and particularly relates to an aerodynamic characteristic analysis method considering rotor body tail rotor interference. Comprising the following steps: S1, respectively modeling a rotor, a fuselage and a tail rotor in three-dimensional modeling software to obtain a rotor model, a fuselage model and a tail rotor model; s2, according to a set grid division strategy, performing grid division on the rotor model, the fuselage model and the tail rotor model to obtain a rotor grid model, a fuselage grid model and a tail rotor grid model; the set grid division strategy comprises setting of a grid type, a computational domain size, a grid number, grid distribution and a boundary layer; s3, a multi-stage involved motion coordinate system is set, the multi-stage involved motion coordinate system comprises a rotating coordinate system, a waving coordinate system and a variable-pitch coordinate system, the rotating motion, the waving motion and the variable-pitch motion of the blades are defined under the rotating coordinate system, the waving coordinate system and the variable-pitch coordinate system respectively, and a blade displacement equation is obtained; and S4, according to the blade displacement equation, the rotor grid model, the fuselage grid model and the tail rotor grid model, simulating a rotor body tail rotor interference flow field, and according to the rotor body tail rotor interference flow field, obtaining aerodynamic characteristics considering rotor body tail rotor interference.

Description

Technical Field

[0001] The invention belongs to the technical field of helicopter aerodynamic design and analysis, and in particular relates to an aerodynamic characteristic analysis method taking into account the interference of a rotor fuselage and a tail rotor. Background Art

[0002] The flow field of a helicopter exhibits obvious unsteady characteristics during flight. In the hovering and low-speed forward flight states, the fuselage and tail rotor are almost completely in the rotor wake interference flow field. This interference will produce impact loads and periodic loads on the helicopter rotor, fuselage, and tail rotor, thereby affecting the helicopter's control stability, vibration, and noise characteristics. In addition, the interaction between the rotor, fuselage, and tail rotor causes the angle of attack of the rotor and tail rotor blade profile to change, affecting the induced velocity distribution and the rotor disk load distribution, resulting in fluctuations in aerodynamic force and power, which brings certain difficulties to the analysis of the helicopter's aerodynamic performance. Therefore, it is of great practical significance to accurately simulate the rotor-fuselage-tail rotor interference flow field and analyze the aerodynamic interference characteristics of the rotor-fuselage-tail rotor.

[0003] There are three main methods for analyzing the aerodynamic characteristics of helicopter rotor fuselage tail rotor: theoretical method, experimental method and numerical simulation method. The theoretical method requires the simplification of the model, and the calculation accuracy is often low, which is not suitable for the calculation of aerodynamic characteristics of unsteady flow fields under complex flow conditions; the experimental method is limited by the influence of model size and measurement technology, and the research cycle is long and the cost is high; thanks to the rapid development of fluid mechanics and computers, numerical simulation methods represented by computational fluid dynamics (CFD) have been applied in helicopter aerodynamics. They are low-cost, short-time and high-precision, and can better handle complex shapes and capture flow field interference details. They are widely used in helicopter flow field interference research.

[0004] Existing technologies are limited by the speed difference between the rotor and tail rotor and the difficulty in simulating the interference flow field. The analysis of helicopter aerodynamic interference characteristics is mostly limited to the rotor fuselage interference flow field, which cannot accurately simulate the actual working environment of the helicopter. The analysis of some complex interference problems is not thorough enough. Summary of the invention

[0005] The technical solution of the present invention comprehensively considers the influence of the rotor tail rotor, provides an aerodynamic characteristics analysis method involving rotor fuselage tail rotor interference, and provides support for helicopter aerodynamic layout design and aerodynamic interference characteristics analysis.

[0006] In order to achieve the above object, the present invention adopts the following technical solution to achieve it.

[0007] An aerodynamic characteristics analysis method considering the interference of a rotor fuselage and a tail rotor, the method comprising:

[0008] S1, modeling the rotor, fuselage, and tail rotor respectively in a 3D modeling software to obtain a rotor model, a fuselage model, and a tail rotor model;

[0009] S2, meshing the rotor model, the fuselage model and the tail rotor model according to a set meshing strategy to obtain a rotor mesh model, a fuselage mesh model and a tail rotor mesh model; the set meshing strategy includes: mesh type, calculation domain size, mesh number, mesh distribution and boundary layer setting;

[0010] S3, setting a multi-level implicated motion coordinate system, the multi-level implicated motion coordinate system includes: a rotating coordinate system, a flapping coordinate system, and a variable pitch coordinate system, and defining the rotation, flapping, and variable pitch motions of the blade in the rotating coordinate system, the flapping coordinate system, and the variable pitch coordinate system, respectively, to obtain a blade displacement equation;

[0011] S4, simulating the rotor-fuselage-tail-rotor interference flow field according to the blade displacement equation, the rotor grid model, the fuselage grid model, and the tail rotor grid model, and obtaining the aerodynamic characteristics considering the rotor-fuselage-tail-rotor interference according to the rotor-fuselage-tail-rotor interference flow field.

[0012] Furthermore,

[0013] In S1, the fuselage model is divided into components and locally simplified on the principle of not affecting the basic flow characteristics of the model, and the non-airfoil sections at the root of the rotor and tail rotor are simplified.

[0014] Furthermore,

[0015] In S2, the grid division strategy is set as follows:

[0016] The grid type is: structured grid, unstructured grid or hybrid grid;

[0017] The mesh methods are: kinematic nested mesh, dynamic mesh or sliding mesh;

[0018] Computational domain size: For the rotor and tail rotor, the computational domain boundary should be between 1.5 and 2 times the chord length from the rotor and tail rotor surface; for the fuselage, the computational domain boundary should be between 15 and 20 times the fuselage length from the fuselage surface;

[0019] Grid distribution: Surface grids are encrypted at the leading edge of the rotor tail rotor blades, the blade tip grids, and the leading edge grids of the fuselage horizontal and vertical tails, and spatial grids are encrypted in the rotor and tail rotor wash areas;

[0020] Boundary layer settings: Set the first layer thickness of the blade boundary layer grid to the blade chord length * 10 -5 , set the first layer thickness of the fuselage boundary layer grid to fuselage length * 10 -5 .

[0021] Furthermore,

[0022] S3, setting a multi-level motion coordinate system, which includes: a rotating coordinate system, a swinging coordinate system, and a variable pitch coordinate system, specifically:

[0023] Taking the rotation center of the rotor or tail rotor as the origin, a rotating coordinate system is established, the X direction of the rotating coordinate system is the incoming flow direction, the Z direction is vertically upward, and the Y direction is determined by the right-hand rule; in the rotating coordinate system, the rotational motion of the rotor or tail rotor is defined;

[0024] In the rotating coordinate system, a flapping coordinate system is established with the flapping hinge position of the rotor or tail rotor as the origin, the X direction of the flapping coordinate system points to the blade tip, the Z direction is vertically upward, and the Y direction is determined by the right-hand rule; in the flapping coordinate system, the flapping motion of the rotor or tail rotor is defined;

[0025] In the flapping coordinate system, a variable pitch coordinate system is established with the variable pitch position of the rotor or tail rotor as the origin, the X direction of the variable pitch coordinate system points to the blade tip, the Z direction is vertically upward, and the Y direction is determined by the right-hand rule; in the variable pitch coordinate system, the variable pitch motion of the rotor or tail rotor is defined;

[0026] The blade displacement equation is obtained according to the rotational motion of the rotor or tail rotor, the flapping motion of the rotor or tail rotor, and the pitch-changing motion of the rotor or tail rotor in the multi-stage involved motion coordinate system.

[0027] Furthermore,

[0028] In S4, the blade displacement equation is assigned to the rotor grid model and the tail rotor grid model to solve the rotor-fuselage tail rotor interference flow field.

[0029] Furthermore,

[0030] In S4, the Reynolds-averaged NS equation is selected as the main control equation to solve the rotor-fuselage tail rotor interference flow field, and the Roe-MUSCL format is used to spatially discretize the Reynolds-averaged NS equation;

[0031] The k-ωSST two-equation turbulence model or the SA turbulence model is selected as the turbulence model of the rotor fuselage tail rotor interference flow field.

[0032] Furthermore,

[0033] In S4,

[0034] The dual-time method is used to time-step the rotor fuselage tail rotor interference flow field. The dual-time method includes physical time and pseudo time. The LU-SGS format is used in pseudo time to advance until the flow field is fully converged.

[0035] In the setting of physical time, the time for the rotor blade to rotate 1° is selected as the physical time during the calculation process. After the rotor flow field is basically converged, the time for the tail rotor blade to rotate 1° is selected as the physical time for numerical simulation until the flow field is fully converged.

[0036] Furthermore,

[0037] In S4,

[0038] The far-field boundary of the rotor-fuselage tail rotor interference flow field is set as the free flow, and the rotor-fuselage tail rotor surface is set as the wall.

[0039] The present invention relates to an aerodynamic characteristics analysis method that comprehensively considers the interference of the rotor fuselage tail rotor. Based on CFD numerical simulation, the influence of the rotor fuselage tail rotor is comprehensively considered by carrying out demand analysis and implementation plan, calculation model processing, calculation grid division, rotor fuselage tail rotor motion definition, and numerical solution setting. The aerodynamic interference characteristics of the rotor fuselage tail rotor in the real working environment of the helicopter are accurately simulated and analyzed, providing support for the helicopter aerodynamic layout design and aerodynamic interference characteristics analysis. Compared with traditional theories and experimental methods, the analysis of some complex interference problems is more intuitive and thorough, greatly saving time and human resource costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of a rotor blade grid provided in an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of a tail rotor blade grid provided in an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of the rotor fuselage tail rotor interference flow field provided in an embodiment of the present invention;

[0043] Figure 4 A schematic diagram of the isolated tail rotor thrust frequency provided by an embodiment of the present invention;

[0044] Figure 5 A schematic diagram of the tail rotor thrust frequency under the rotor fuselage tail rotor aerodynamic interference flow field provided by an embodiment of the present invention;

[0045] Figure 6 A schematic diagram of the vertical tail lateral force frequency of the rotor fuselage tail rotor aerodynamic interference flow field provided by an embodiment of the present invention;

[0046] Figure 7 A schematic diagram of the vertical force frequency of the right horizontal tail of the rotor fuselage tail rotor aerodynamic interference flow field provided by an embodiment of the present invention;

[0047] Figure 8 A schematic diagram of the vertical force frequency of the left horizontal tail of the rotor fuselage tail rotor aerodynamic interference flow field provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is described in detail below with reference to the accompanying drawings.

[0049] In the process of helicopter model development, the CFD method is usually used to determine the aerodynamic characteristics of the rotor, tail rotor and fuselage respectively. The influence between the rotor, fuselage and tail rotor is rarely considered comprehensively. It is impossible to accurately simulate and analyze the aerodynamic interference characteristics of the rotor, fuselage and tail rotor in the real working environment of the helicopter, and the analysis of some complex interference problems is not thorough enough. The present invention develops an aerodynamic characteristics analysis method that comprehensively considers the aerodynamic characteristics of the rotor, fuselage and tail rotor interference through numerical simulation scheme formulation, calculation model processing, calculation grid division, rotor fuselage and tail rotor motion definition, and numerical solution setting, providing support for helicopter aerodynamic layout design and aerodynamic interference characteristics analysis.

[0050] The main steps of the present invention are:

[0051] 1. Numerical simulation plan formulation

[0052] According to the purpose of numerical simulation, object analysis is carried out to confirm the state consistency, and a numerical simulation plan is formulated, including calculation state, model processing requirements, and selection of calculation methods.

[0053] a) By carrying out numerical simulation of the aerodynamic interference between the rotor-fuselage and tail rotor, the aerodynamic force of the fuselage and its components (short wing, horizontal tail, vertical tail, etc.), the thrust and torque of the rotor / tail rotor blades and other parameters in the interference flow field are obtained.

[0054] b) Select the calculation state based on the purpose of numerical simulation, including hovering, level flight, side flight, oblique descent, etc.;

[0055] c) Due to the complex spatial motion of the rotor and tail rotor (blade rotation and periodic pitch change, flapping, and shimmy motion) and strong interference, motion nested grids, dynamic grids or sliding grids and unsteady calculation methods are selected to carry out numerical simulation.

[0056] 2. Computational model processing

[0057] According to the object and purpose of numerical simulation, the numerical simulation shape is adaptively processed, including the fuselage model, rotor model and tail rotor model processing, etc. According to the calculation conditions, the geometric dimensions of the calculation model are determined.

[0058] The geometric model is processed in the 3D modeling software. In principle, the fuselage model is divided into parts and locally simplified without affecting the basic flow characteristics of the model, and the non-airfoil sections at the root of the rotor and tail rotor are simplified.

[0059] 3. Computational grid division

[0060] According to the numerical simulation calculation model, determine the grid division strategy, including grid type, computational domain size, number of grids, grid distribution, boundary layer scheme, etc. Figure 1-Figure 2 .

[0061] a) For the numerical simulation of the combined interference of rotor-fuselage and tail-rotor, the rotor, fuselage and tail-rotor are divided into structured grid, unstructured grid or hybrid grid;

[0062] b) The boundary of the computational domain should be far enough away from the rotor fuselage and tail rotor model to ensure stable and accurate calculations;

[0063] c) The mesh method can be selected from motion nested mesh, dynamic mesh or sliding mesh. The motion nested mesh method generates body-fitting meshes for complex moving parts (rotors, tail rotor blades) separately, and accurately describes the multi-dimensional motion of blades through motion nesting. During the flow field calculation, the relative position between the blade mesh and the background mesh changes continuously. It should be ensured that there are enough layers in the overlapping area between the background mesh and the nested mesh to complete the hole boundary unit identification and contribution unit search to realize the interpolation iteration of the nested area; when the dynamic mesh and sliding mesh generate the rotor tail rotor blade mesh, the background mesh in its moving area should be encrypted to ensure accurate simulation of the blade flow details.

[0064] d) The leading edge and tip grids of the rotor tail rotor blades and the leading edge grids of the fuselage horizontal and vertical tail have good conformal properties, and spatial grid encryption is performed in the rotor and tail rotor flow wash areas.

[0065] e) Set the first layer grid thickness, number of layers and growth rate of the blade boundary layer. The first layer grid thickness of the blade boundary layer should fully consider the viscosity of the boundary layer, that is, satisfy the viscosity factor y + ≈1.

[0066]

[0067] 4. Definition of rotor fuselage tail rotor motion

[0068] According to the purpose of numerical simulation of rotor-fuselage tail rotor, motion trim is carried out for different weight centers of gravity and different engine speeds of the helicopter, and the result is used as the motion input of the rotor and tail rotor blades.

[0069] The hovering state mainly focuses on motion parameters such as fuselage attitude, rotor / tail rotor blade speed, collective pitch and taper angle;

[0070] The forward flight state mainly focuses on the forward flight speed, fuselage attitude, rotor / tail rotor blade speed, periodic motion (including pitch change, flapping, shimmy) and other motion parameters;

[0071] Displacement equation for rotor / tail rotor blades:

[0072] S(ψ)=a 0 +a1 ·cos(ψ)+b 1 ·sin(ψ)+a 2 ·cos(2ψ)

[0073] +b 2 ·sin(2ψ)+a 3 ·cos(3ψ)+b 3 ·sin(3ψ)+…

[0074]

[0075] Where S(ψ) represents the blade displacement (flapping, pitch change, shimmy motion) corresponding to the azimuth angle ψ, the rotor speed is ω, and the number of blades is n.

[0076] By setting up a multi-level motion coordinate system (including rotation, flapping, and pitch-variation coordinate systems), the blade displacement equation is defined in the corresponding coordinate system to achieve the complex motion coupling of each blade. By giving the blade mesh motion constraints, the motion control of the rotor and tail rotor is achieved.

[0077] 5. Numerical solution settings

[0078] In order to better capture the special flow details in the aerodynamic interference flow field of the rotor fuselage and tail rotor, the influence of the compressible flow and incompressible flow of the rotor is comprehensively considered, and the spatial motion of the rotor tail rotor is accurately described. The flow field control equations, spatial discretization methods, time marching formats, turbulence models and boundary conditions are defined.

[0079] a) Flow field solution The Reynolds-averaged NS equation is selected as the main control equation for numerical simulation of rotor-fuselage-tail rotor combination interference.

[0080] b) The Reynolds-averaged NS equations are spatially discretized using the finite volume method, using the Roe-MUSCL format.

[0081] c) Due to the unsteady characteristics of the flow field disturbed by the tail rotor of the rotor fuselage, a dual-time method (including physical time and pseudo-time) is used for time stepping. The flow control equation is advanced in pseudo-time within each physical time step, and the unsteady problem is converted into a process of solving a steady problem. The LU-SGS format is used in pseudo-time to advance until complete convergence.

[0082] In the setting of physical time, the time for the blade to rotate 1° is usually selected. Since the tail rotor speed is usually much greater than the rotor speed, in order to accelerate the convergence of the flow field, the time for the rotor blade to rotate 1° is selected as the physical time in the early calculation process. After the rotor flow field is basically converged, the time for the tail rotor blade to rotate 1° is selected as the physical time for numerical simulation until the combined interference flow field is completely converged.

[0083] The flow field convergence can be accelerated and the computational efficiency can be improved by directly setting the pseudo time step.

[0084] The CFL number setting can be adjusted small in the early stage to stabilize the solution, and then increased to ensure solution efficiency after the flow field is stable.

[0085] d) In order to better capture the flow in the boundary layer of the blade, you can choose the k-ωSST two-equation turbulence model or the SA turbulence model. The k-ωSST two-equation turbulence model is a neutral turbulence model of k-ω and k-ε. The k-ω turbulence model is used in the near-wall flow field to better predict the turbulent viscosity coefficient and increase the simulation accuracy. The k-ε model is less sensitive to the incoming flow conditions and is more applicable in the boundary layer and free shear layer to improve the solution efficiency.

[0086] e) The setting of boundary conditions can select far-field boundary conditions and object surface boundary conditions according to the purpose of CFD numerical simulation.

[0087] According to the above steps, the simulation of the rotor-fuselage-tail rotor combined interference flow field is completed. Figure 3 , the aerodynamic interference characteristics of the rotor, fuselage and tail rotor in the interference flow field are obtained, and the isolated tail rotor thrust frequency is shown in Figure 4 The tail rotor thrust frequency under the rotor fuselage tail rotor aerodynamic interference flow field is shown in Figure 5 , the frequency of the vertical tail lateral force of the rotor fuselage tail rotor aerodynamic interference flow field is Figure 6 The vertical force frequency of the right horizontal tail in the aerodynamic interference flow field of the rotor fuselage and tail rotor is Figure 7 The vertical force frequency of the left horizontal tail in the aerodynamic interference flow field of the rotor fuselage and tail rotor is Figure 8 .

[0088] The present invention relates to an aerodynamic characteristics analysis method that comprehensively considers the interference of the rotor fuselage tail rotor. Based on CFD numerical simulation, the influence of the rotor fuselage tail rotor is comprehensively considered by carrying out demand analysis and implementation plan, calculation model processing, calculation grid division, rotor fuselage tail rotor motion definition, and numerical solution setting. The aerodynamic interference characteristics of the rotor fuselage tail rotor in the real working environment of the helicopter are accurately simulated and analyzed, providing support for the helicopter aerodynamic layout design and aerodynamic interference characteristics analysis. Compared with traditional theories and experimental methods, the analysis of some complex interference problems is more intuitive and thorough, greatly saving time and human resource costs.

Claims

1. An aerodynamic characteristics analysis method considering the interference of rotor fuselage and tail rotor, characterized in that: The method comprises: S1, modeling the rotor, fuselage, and tail rotor respectively in a 3D modeling software to obtain a rotor model, a fuselage model, and a tail rotor model; S2, meshing the rotor model, the fuselage model and the tail rotor model according to a set meshing strategy to obtain a rotor mesh model, a fuselage mesh model and a tail rotor mesh model; the set meshing strategy includes: mesh type, calculation domain size, mesh number, mesh distribution and boundary layer setting; S3, setting a multi-level implicated motion coordinate system, the multi-level implicated motion coordinate system includes: a rotating coordinate system, a flapping coordinate system, and a variable pitch coordinate system, and defining the rotation, flapping, and variable pitch motions of the blade in the rotating coordinate system, the flapping coordinate system, and the variable pitch coordinate system, respectively, to obtain a blade displacement equation; S4, simulating the rotor-fuselage-tail-rotor interference flow field according to the blade displacement equation, the rotor grid model, the fuselage grid model, and the tail rotor grid model, and obtaining the aerodynamic characteristics considering the rotor-fuselage-tail-rotor interference according to the rotor-fuselage-tail-rotor interference flow field.

2. The aerodynamic characteristics analysis method considering the rotor fuselage tail rotor interference according to claim 1 is characterized in that: In S1, the fuselage model is divided into components and locally simplified on the principle of not affecting the basic flow characteristics of the model, and the non-airfoil sections at the root of the rotor and tail rotor are simplified.

3. The aerodynamic characteristics analysis method considering the rotor fuselage tail rotor interference according to claim 1 is characterized in that: In S2, the grid division strategy is set as follows: The grid type is: structured grid, unstructured grid or hybrid grid; The mesh methods are: kinematic nested mesh, dynamic mesh or sliding mesh; Computational domain size: For the rotor and tail rotor, the computational domain boundary should be between 1.5 and 2 times the chord length from the rotor and tail rotor surface; for the fuselage, the computational domain boundary should be between 15 and 20 times the fuselage length from the fuselage surface; Grid distribution: Surface grids are encrypted at the leading edge of the rotor tail rotor blades, the blade tip grids, and the leading edge grids of the fuselage horizontal and vertical tails, and spatial grids are encrypted in the rotor and tail rotor wash areas; Boundary layer settings: Set the first layer thickness of the blade boundary layer grid to the blade chord length * 10 -5 , set the first layer thickness of the fuselage boundary layer grid to fuselage length * 10 -5 .

4. The aerodynamic characteristics analysis method considering the rotor fuselage tail rotor interference according to claim 3 is characterized in that: S3, setting a multi-level motion coordinate system, which includes: a rotating coordinate system, a swinging coordinate system, and a variable pitch coordinate system, specifically: Taking the rotation center of the rotor or tail rotor as the origin, a rotating coordinate system is established, the X direction of the rotating coordinate system is the incoming flow direction, the Z direction is vertically upward, and the Y direction is determined by the right-hand rule; in the rotating coordinate system, the rotational motion of the rotor or tail rotor is defined; In the rotating coordinate system, a flapping coordinate system is established with the flapping hinge position of the rotor or tail rotor as the origin, the X direction of the flapping coordinate system points to the blade tip, the Z direction is vertically upward, and the Y direction is determined by the right-hand rule; in the flapping coordinate system, the flapping motion of the rotor or tail rotor is defined; In the flapping coordinate system, a variable pitch coordinate system is established with the variable pitch position of the rotor or tail rotor as the origin, the X direction of the variable pitch coordinate system points to the blade tip, the Z direction is vertically upward, and the Y direction is determined by the right-hand rule; in the variable pitch coordinate system, the variable pitch motion of the rotor or tail rotor is defined; The blade displacement equation is obtained according to the rotational motion of the rotor or tail rotor, the flapping motion of the rotor or tail rotor, and the pitch-changing motion of the rotor or tail rotor in the multi-stage involved motion coordinate system.

5. The aerodynamic characteristics analysis method considering the rotor fuselage tail rotor interference according to claim 4 is characterized in that: In S4, the blade displacement equation is assigned to the rotor grid model and the tail rotor grid model to solve the rotor-fuselage tail rotor interference flow field.

6. The aerodynamic characteristics analysis method considering the rotor fuselage tail rotor interference according to claim 5 is characterized in that: In S4, the Reynolds-averaged NS equation is selected as the main control equation to solve the rotor-fuselage tail rotor interference flow field, and the Roe-MUSCL format is used to spatially discretize the Reynolds-averaged NS equation; The k-ωSST two-equation turbulence model or the SA turbulence model is selected as the turbulence model of the rotor fuselage tail rotor interference flow field.

7. The aerodynamic characteristics analysis method considering the rotor fuselage tail rotor interference according to claim 6 is characterized in that: In S4, The dual-time method is used to time-step the rotor fuselage tail rotor interference flow field. The dual-time method includes physical time and pseudo time. The LU-SGS format is used in pseudo time to advance until the flow field is fully converged. In the setting of physical time, the time for the rotor blade to rotate 1° is selected as the physical time during the calculation process. After the rotor flow field is basically converged, the time for the tail rotor blade to rotate 1° is selected as the physical time for numerical simulation until the flow field is fully converged.

8. The aerodynamic characteristics analysis method considering the rotor fuselage tail rotor interference according to claim 6 is characterized in that: In S4, The far-field boundary of the rotor-fuselage tail rotor interference flow field is set as the free flow, and the rotor-fuselage tail rotor surface is set as the wall.

Images