基于特征线理论的辨识法在激波装配中的应用

A Shock Detection Method Based on the Theory of Characteristics and its Application in Shock-Fitting Methods

准确地给出激波位置信息对于激波装配极为重要.但是,在使用计算流体力学(computational fluid dynamics,CFD)方法模拟复杂流动时很难准确地给出激波的位置.根据激波捕捉得到的流场信息确定的激波位置往往带有极大误差,在定常问题的模拟中,这种误差可以随着迭代逐渐消除,然而在非定常问题的模拟中,这种误差往往会积累甚至导致计算崩溃.文章将基于特征线理论的激波辨识技术应用到激波装配中,根据已有流场信息准确判断激波的位置.对于定常问题,该方法的应用加速了收敛速度;对于非定常问题,该方法的应用可以极大地避免初始误差的产生.

It is very important to detect shock positions for a shock-fitting technique. However,it is difficult to get the exact position from the computational results. Numerical errors caused by captured methods usually lead to deflections of shock wave positions. In a steady flow,the deflected errors will be eliminated by iterations. In an unsteady flow,however,the deflected errors may be accumulated and led to wrong results. In the present work,a shock detection method based on the theory of characteristics was used to detect shock positions in shock-fitting techniques. This method is proved to be with good performance both in steady flows and unsteady flows.