Aircraft multi-body separation CFD simulation method and system based on hybrid dynamic grid technology

Abstract

The invention discloses an aircraft multi-body separation CFD simulation method and system based on a hybrid power grid technology. The method comprises the following steps of dividing an aircraft multi-body into the CFD numerical simulation of multiple stages from separation start to separation end; and completing the CFD numerical simulation and splicing of each stage sequentially according toa grid deformation technology and a grid reconstruction technology; and combining a grid deformation technology and a staged grid reconstruction technology. The aircraft multi-body separation CFD numerical simulation method based on the hybrid dynamic grid technology can give full play to the advantages of high calculation efficiency and high calculation precision of thegrid deformation technologyin a small displacement range, also can give full play to the advantage that the staged grid reconstruction technology can effectively improve the grid quality in a staged manner under the conditionof large displacement, and improves the calculation precision, so that the method can be effectively applied to the research on the multi-body separation problem of the unsteady, high-Reynolds-numberand large-displacement aircrafts.

Description

technical field [0001] The invention relates to the field of aircraft multi-body separation simulation, in particular to a CFD simulation method and system for aircraft multi-body separation based on hybrid dynamic grid technology. Background technique [0002] The problem of multi-body separation of aircraft is mostly in the harsh environment of low altitude and high dynamic pressure. Due to the time-varying relative position and relative velocity between multiple bodies, shock wave / shock wave interference, shock wave boundary layer interference, boundary layer separation, and vortex flow will be induced. and other flow phenomena, so that the flow field parameters are in a highly nonlinear and unsteady state, which seriously interferes with the aerodynamic and kinematic characteristics of the aircraft body and separated parts. Many of the above factors directly lead to the multi-body separation process often becoming a high-risk mission action. Therefore, it is necessary t...

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Problems solved by technology

[0011] Using the first method, the nested grid technology, requires repeated interpolation between the background grid and the moving grid, and the calculation efficiency is low. During the frequent interpolation process, it will also bring accumulated errors, which directly affects the final calculation accuracy.

[0012] Using the second method, grid reconstruction technology, the grid reconstruction process itself requires a lot of computing resources, and at the same time, a large number of interpolation calculations are required before and after grid reconstruction, and the calculation efficiency is very poor.

In addition, because the simple mesh reconstruction technology is generally only suitable for the study of steady problems, it is not suitable for the study of multi-body separation problems of unsteady aircraft

[0013] The third method, the immersed boundary technique, can simulate dynamic boundary problems with complex shapes, but it is only suitable for low Reynolds number problems, and the Reynolds number involved in aircraft multi-body separation problems is often very high, so the immersed boundary technique is not suitable. Applicable to the study of multi-body separation problems of aircraft

[0014] Using the fourth method, mesh deformation technology, when this technology deals with boundary motion problems with large displacements, due to the large range and range of motion, relying solely on the deformation capabilities of the mesh such as stretching and compression will lead to poor mesh quality. The sharp drop will affect the CFD numerical calculation accuracy, and the calculation cannot even converge. Therefore, the simple mesh deformation technology is not suitable for the multi-body separation problem of large-displacement aircraft

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