燃气自由射流的高精度间断有限元数值模拟

Numerical Simulation of Gas Free-jet Using High-precision Discontinuous Finite Element Method

将三阶间断有限元方法推广到轴对称Euler方程组的数值求解中,并将其用于数值模拟复杂燃气的自由射流.计算结果表明,采用该方法能够较好地捕捉到包含激波、滑移线以及三波交点等复杂流场波系结构,马赫盘位置与实验测量结果吻合较好,在间断位置不出现非物理振荡或抹平间断现象,这表明该方法是有效的,具有较高的计算精度,为燃气射流的数值研究提供了一种新的手段.

Complicated gas free-jet was simulated numerically using third-order discontinuous finite element method which was developed to solve axisymmetric Euler equations on the basis of two-dimensional conservation laws. The calculation results show that, the shock-wave structures of complicated flow field including shock waves, slipstreams and the triple point, are well captured by this method. Comparisons of Mach disk location show excellent agreement between numerical results and experimental measurements. Neither nonphysical oscillation nor artificial viscosity occurs near the discontinuous point. This method is robust, and it offers a new means for numerical study of gas jet.