A Method for Predicting Aerodynamic Forces of Fast Turbulent Wall Functions Based on Coarse Mesh

A prediction method and a coarse grid technology, which are applied in the fields of electrical digital data processing, CAD numerical modeling, and special data processing applications, etc., can solve the problems of slow calculation convergence speed and many internal resources of the computer, so as to reduce workload, Improve calculation efficiency, good calculation and effect

Active Publication Date: 2022-05-03
CALCULATION AERODYNAMICS INST CHINA AERODYNAMICS RES & DEV CENT
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  • Application Information

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Problems solved by technology

[0003] In order to overcome the deficiencies of the prior art, the present invention provides a method for predicting the aerodynamic force of the rapid turbulent wall function based on the coarse grid, which solves the calculation convergence caused by the sudden increase of the grid near the wall in the simulation of the complex turbulent flow in the prior art. The speed becomes slower, takes up more internal resources of the computer, and has serious numerical rigidity problems, etc.

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  • A Method for Predicting Aerodynamic Forces of Fast Turbulent Wall Functions Based on Coarse Mesh
  • A Method for Predicting Aerodynamic Forces of Fast Turbulent Wall Functions Based on Coarse Mesh
  • A Method for Predicting Aerodynamic Forces of Fast Turbulent Wall Functions Based on Coarse Mesh

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Embodiment 1

[0063] Such as Figure 1 to Figure 8 As shown, a method for predicting the aerodynamic forces of fast turbulent wall functions based on coarse grids includes the following steps:

[0064] S1, establish the wall mesh model of the aircraft, and obtain the initial value of the wall shear stress of the aircraft in the wall mesh, the formula is:

[0065]

[0066] Among them, τ is the shear stress, τ w is the wall shear stress, μ w is the wall molecular viscosity coefficient, μt is the turbulent flow viscosity coefficient, U is the inner wall parallel velocity of the wall grid, y is the wall distance, is the sign of the partial derivative, is the partial derivative of the wall parallel velocity in the wall normal direction in the wall mesh, U P is the velocity of grid points on the wall;

[0067] S2, get the friction velocity U of the aircraft in the wall grid τ , whose formula is:

[0068]

[0069] Among them, ρ w is the wall density;

[0070] S3, calculate the dim...

Embodiment 2

[0109] Such as Figure 1 to Figure 8 As shown, this embodiment is based on Embodiment 1, reflecting the technical effect of adopting the present invention.

[0110] This technology uses the wall function based on the analytical velocity distribution in the wall coarse grid, and obtains the friction velocity through constructor iteration, which can effectively improve the prediction accuracy of the wall coarse grid, and with the increase of the wall grid distance, the grid volume The overall reduction can significantly save computing time and computing memory.

[0111] figure 2 , image 3 is the boundary layer velocity distribution of the hyper-slab turbulent flow with incoming flow Ma=2.85, when the wall function is not used ( figure 2 ), the numerical results of the coarse grid, the results of the dense grid, and the experimental results have large deviations, and the accuracy becomes worse with the increase of the grid wall distance, while image 3 After using the wall...

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Abstract

The invention discloses a method for predicting the aerodynamic force of a fast turbulent wall surface function based on a coarse grid, comprising the following steps: S1, establishing a wall surface grid model of an aircraft, and obtaining an initial value of the wall shear stress of the aircraft in the wall surface grid; S2 , to obtain the friction velocity of the aircraft in the wall grid; S3, to calculate the dimensionless wall distance in the wall grid; S4, to calculate the friction velocity in the wall grid; S5, to calculate the residual; S6, to judge whether the friction velocity is convergent; S7, calculating the turbulent viscosity coefficient in the wall grid; S8, updating the virtual point turbulent viscosity coefficient in the wall grid. The invention solves the disadvantages of the prior art, such as the slow calculation convergence speed caused by the sudden increase of grids near the wall surface, occupying a lot of computer internal resources, and having serious numerical rigidity problems in the simulation of complex turbulent flow in engineering.

Description

technical field [0001] The invention relates to the technical field of computational fluid dynamics Reynolds average turbulence numerical simulation, in particular to a method for predicting the aerodynamic force of a fast turbulent wall function based on a coarse grid. Background technique [0002] Numerical simulation of turbulence is widely used in the design of hypersonic vehicles and the integrated design of propulsion systems. , inner runner, etc.) and aircraft trajectory optimization provide better research support, which play a very important role in practical applications and have strong practical significance. At present, RANS methods that consume less computing resources are mostly used at present. For the SST k-ω model commonly used in engineering, if it is necessary to accurately simulate wall friction and heat flow, the wall mesh is required to be dense enough, usually y+≈1, which will lead to a sudden increase in the mesh near the wall when simulating complex...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G06F30/15G06F30/28G06F111/10G06F113/08G06F119/14
CPCG06F30/15G06F30/28G06F2111/10G06F2113/08G06F2119/14Y02T90/00
Inventor 王新光何琨陈坚强毛枚良陈琦万钊张毅峰江定武郭勇颜张爱婧
Owner CALCULATION AERODYNAMICS INST CHINA AERODYNAMICS RES & DEV CENT
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