非结构混合网格高超声速绕流与磁场干扰数值模拟

对均匀磁场干扰下的二维钝头体无粘高超声速流场进行了基于非结构混合网格的数值模拟.受磁流体力学方程组高度非线性的影响及考虑到数值模拟格式的精度,目前在此类流场的数值模拟中大多使用结构网格及有限差分方法,因而在三维复杂外形及复杂流场方面的研究受到限制.本文主要探索使用非结构网格(含混合网格)技术时的数值模拟方法.控制方程为耦合了Maxwell方程及无粘流体力学方程的磁流体力学方程组,数值离散格式采用Jameson有限体积格心格式,5步Runge-Kutta显式时间推进.计算模型为二维钝头体,初始磁场均匀分布.对不同磁感应强度影响下的高超声速流场进行了数值模拟,并与有限的资料进行了对比,得到了较符合的结果.

Numerical method on unstructured hybrid grid for hypersonic flows with magnetic fields

Numerical method on unstructured hybrid grid for twodimensional hypersonic flow with magnetic field is presented.The singularity of Jacobian matrix of the magneto-hydrodynamic equations makes the general numerical methods difficult to simulate such flow field.Most researches on the numerical schemes for the magneto-hydrodynamic equations are limited to the structured grid based finite difference methods.In the consideration of three-dimensional complex cases,it is necessary to develop numerical methods on unstructured grids(also on hybrid grids),which is the purpose of this paper.The numerical scheme is finite volume method implemented on hybrid grid,with explicit 5-steps Runge-Kutta time step.The geometrical model is a two-dimensional blunt body, with uniform magnetic field distribution.The characteristics of the hypersonic flow around the blunt body are numerically analyzed with respect to the different magnetic strengths.Numerical results are obtained and compared with some limited references.