In numerical simulations of complex flows with discontinuities, it is necessary to use nonlinear schemes. The spectrum of the scheme used have a significant impact on the resolution and stability of the computation. Based on the approximate dispersion relation method, we combine the corresponding spectral property with the dispersion relation preservation proposed by De and Eswaran (J. Comput. Phys. 218 (2006) 398-416) and propose a quasi-linear dispersion relation preservation (QL-DRP) analysis method, through which the group velocity of the nonlinear scheme can be determined. In particular, we derive the group velocity property when a high-order Runge-Kutta scheme is used and compare the performance of different time schemes with QL-DRP. The rationality of the QL-DRP method is verified by a numerical simulation and the discrete Fourier transform method. To further evaluate the performance of a nonlinear scheme in finding the group velocity, new hyperbolic equations are designed. The validity of QL-DRP and the group velocity preservation of several schemes are investigated using two examples of the equation for one-dimensional wave propagation and the new hyperbolic equations. The results show that the QL-DRP method integrated with high-order time schemes can determine the group velocity for nonlinear schemes and evaluate their performance reasonably and efficiently.
翻译:在对不连续的复杂流动进行数字模拟时,有必要使用非线性方案。所使用的办法的频谱对计算分辨率和稳定性有重大影响。根据大致分散关系法,我们将相应的光谱属性与De和Eswaran(J.Compuut.Phys. 218(2006) 398-416)提议的分散关系保护结合起来,并提议一种准线性分散关系保护分析方法(QL-DRP),通过这种方法可以确定非线性方案的组合速度。特别是,在使用高阶 Runge-Kutta 办法时,我们得出集团速度属性,并将不同时间方案的性能与QL-DRP比较。 QL-DRP方法的合理性经数字模拟和离散的Fourier变法核实。为了进一步评价非线性方案在寻找集团速度时的性能,可以设计新的超线性方程方程式。 QL-DRP和若干办法的集团速度保存率特性,正在使用一个水平方程式和新方程式的等式不连续性等距系统,用两个例子来评估其单式高度和新方程式的等式系统,以显示一维的等式和新等式的等式的等式的性能,可以用高等式的性能和新等式分析。