Method for processing large airfoil attach angle solid wall boundary based on Riemannian problem

Abstract

The invention discloses a method for processing a large airfoil attach angle solid wall boundary based on a Riemannian problem. For a large two-dimensional airfoil attach angle problem with a control equation as a Euler equation, the Riemannian problem is raised up in the normal direction of a sliding solid wall, the Riemannian problem is solved based on a shock wave or rarefaction wave relation, then, the value of the solid wall boundary is acquired, and a solid wall boundary condition is given; the method fully utilizes assurance of the solution of the Riemannian problem, the problem that usually negative pressure is easily generated to the solid wall boundary condition is solved, and the method is also used for small attach angle situations and has general applicability. The method has the advantages that the method for processing the large airfoil attach angle solid wall boundary solves the problem that negative pressure is easily generated in the two-dimensional airfoil flow field calculation process under a large attach angle, can be used for ordinary flow field calculation solid wall processing, and has good generality.

Description

technical field [0001] The invention relates to the solid wall boundary processing in the numerical simulation of compressible fluid, especially the solid wall boundary processing method in the calculation of airfoil flow around and numerical calculation under high angle of attack Background technique [0002] In order to obtain good flight maneuverability and agility, modern high-performance fighter jets and tactical missiles are often required to fly at a large angle of attack. Flight and maneuvering at high angles of attack are one of the important characteristics of modern fighters. It can accurately simulate the unsteady flow field structure at high angles of attack and predict the corresponding unsteady aerodynamic characteristics at high angles of attack. It is of great importance to the design of modern fighters and their control systems. important. The flow field at a large angle of attack is more complicated. When the current commercial software and numerical algo...

AI Technical Summary

Problems solved by technology

The flow field at a large angle of attack is more complicated. When the current commercial software and numerical algorithms calculate the flow field around the wing, when the angle of attack reaches a certain level (about 20 degrees), negative pressure problems are prone to occur and the calculation fails.

This is because there is a low-pressure area on the back of the upper edge of the wing at a high angle of attack. Simple boundary processing or non-physical processing may cause negative pressure near the boundary, resulting in the inability to perform correct numerical simulations.

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