Partition disturbance domain updating calculation method for steady viscous compressible streaming of aircraft

An aircraft, viscous technology, applied in the field of partition disturbance domain update calculation, can solve the problems of inviscid-viscous partition partition difficulty, and achieve the effect of improving robustness and adaptability, reducing implementation difficulty, and avoiding information transformation

Active Publication Date: 2020-09-11
BEIHANG UNIV
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  • Abstract
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Problems solved by technology

[0008] b. Aiming at the difficult partition problem of most non-viscous-viscous partition calculations, the present invention will dynamically and adaptively divide the non-viscous domain participating in the calculation in the aircraft flow field grid and the viscous domain that needs to consider the viscous effect, the non-viscous domain, The sticky domain will be updated adaptively at each iteration step

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  • Partition disturbance domain updating calculation method for steady viscous compressible streaming of aircraft
  • Partition disturbance domain updating calculation method for steady viscous compressible streaming of aircraft
  • Partition disturbance domain updating calculation method for steady viscous compressible streaming of aircraft

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Embodiment 1

[0220] Simulate the problem of Mach number 2.5 laminar flow through 5° wedge angle, figure 2 It shows the evolution process of the convective and viscous dynamic domains under the two operations of adding and deleting units in the partition disturbance domain update calculation method; in the figure η c , η v Respectively represent the ratio of the grid quantity of the convective, viscous dynamic domain and the preset computational domain, N max Indicates the number of iterations required for solution convergence. In this embodiment, the flow field is initialized with flow conditions, and the disturbance is generated from the wall boundary. In the first step of the solution, the initial convective dynamic domain includes the 10-layer adjacent cells of the wall, and the initial viscous dynamic domain includes the adjacent cells of the wall. In the early stage of the solution, the two types of dynamic domains are gradually expanded by adding unit operations. At step 330, as...

Embodiment 2

[0223] In the case of adiabatic wall and cold wall, the Mach number is 3.5 and the Reynolds number is 5.83×10 6 The problem of laminar flow through a flat plate is simulated, image 3 In the case of two kinds of wall surfaces, the calculation method of the partition disturbance domain update of the present invention is at ε a,c =10 -5 , ε a,v =10 -2 , ε d =10 -7 The dynamic domain range determined at the time. In the two wall cases, the convective dynamic domain and the viscous dynamic domain are established according to the wall boundary, and gradually expand from the lower boundary of the preset calculation domain to the upper boundary in the early stage of the solution, as shown in image 3 line 1 of the . image 3 The second row of , compares the maximum convective dynamic domains of the two wall cases. Compared with the adiabatic wall case, the boundary layer thickness of the cold wall case is smaller and the leading edge shock wave strength is smaller, so the η of...

Embodiment 3

[0226] For NACA0012 airfoil, the incoming flow Mach number is 0.5, and the incoming flow Reynolds number is 10 4 , 0° angle of attack for simulation, Figure 4 The update calculation method of the partition perturbation domain is given, using the 3rd-order R-K explicit and LU-SGS implicit two time-advancing schemes at ε a,c =10 -5 , ε a,v =10 -2 , ε d =10 -7 Time dynamic domain evolution process. Early in the solution, the convective and viscous dynamic domains grow together with the disturbance propagation from the wall boundary, as in step 173 for the 3rd order R-K scheme. In the case of subsonic speed, the convective dynamic domain will grow to the entire preset calculation domain, while the maximum viscous dynamic domain still only includes a small part of the preset calculation domain, η v The peak values ​​are 0.692 and 0.673 for the explicit and implicit formats, respectively. The lower the Reynolds number, the thicker the boundary layer. Thus, the viscous dyna...

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Abstract

The invention discloses a partition disturbance domain updating calculation method for steady viscous compressible streaming of an aircraft, and belongs to the field of computational fluid mechanics.The method comprises the following steps: reading a file; initializing a flow field; establishing an initial convection dynamic domain and an initial viscosity dynamic domain; allocating a storage space; assigning a conservation amount of the boundary virtual grid according to the boundary condition type; estimating a residual error; performing time integration; increasing the convection dynamic domain; reducing convection and viscosity dynamic domains; reallocating the storage space; increasing a viscous dynamic domain; repeating the above steps until a convergence condition is reached; and outputting a result. According to the invention, the convection dynamic domain and the viscosity dynamic domain which can be adaptively increased / decreased are adopted; only the disturbed units which are not converged yet are solved, the viscous effect is only considered in part of the disturbed units, the calculated amount of a single iterative step and the total iterative step number can be effectively reduced, and therefore the convergence rate of solving the steady viscous compressible streaming of the aircraft is increased.

Description

technical field [0001] The invention belongs to the field of computational fluid dynamics, and in particular relates to a calculation method for updating a partitioned disturbance domain suitable for numerical simulation of a constant viscous compressible flow around an aircraft. Background technique [0002] Although the substantial improvement in computer hardware performance has enabled the solution of the viscous flow governing equation N-S equation, it is still very time-consuming to numerically simulate the viscous flow around the real aircraft shape with a grid with sufficient resolution, and it is difficult to meet the requirements of fluid mechanics, aircraft Practical application needs of design and other disciplines. In current computational fluid dynamics, the time-advancing method is commonly used to simulate the steady viscous compressible flow around the aircraft; this method can solve subsonic and supersonic flows at the same time, and is suitable for a large...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F30/15G06F30/28
CPCG06F30/15G06F30/28Y02T90/00
Inventor 蒋崇文胡姝瑶高振勋李椿萱
Owner BEIHANG UNIV
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