A conservative TVD scheme is adopted to solve the equations governing the three-dimensional flow of a nonideal compressible conducting fluid in a magnetic field. The eight-wave equations for magnetohydrodynamics (MHD) are proved to be a non-strict hyperbolic system, therefore it is difficult to develop its eigenstructure. Powell developed a new set of equations which cannot be numerically simulated by conservative TVD scheme directly due to its non-conservative form. A conservative TVD scheme augmented with a new set of eigenvectors is proposed in the paper. To validate this scheme, 1-D MHD shock tube, unsteady MHD Rayleigh problem and steady MHD Hartmann problem for different flow conditions are simulated. The simulated results are in good agreement with the existing analytical results. So this scheme can be used to effectively simulate high-conductivity fluids such as cosmic MHD problem and hypersonic MHD flow over a blunt body, etc.
magnetohydrodynamics (MHD), numerical simulation, TVD, MHD Rayleigh flow, MHD Hartmann flow
Citation:Lu H Y, Lee C H. Simulation of three-dimensional nonideal MHD flow at highThe physical mechanisms in space and near-space physics are involved in the interaction of aerodynamics and electromagnetic dynamics. For instance, investigations have indicated that the strength of local magnetic field on the solar surface is of the order of kilogauss, and the elements of gas in the vicinity of solar surface are almost fully ionized. Therefore, the physical activities on solar surface are controlled by the interactions of strong magnetic field and plasma [1-3]. Renewed scientific interest has arisen all over the world for the potential application of MHD processes for the advancement of flight vehicles. In the early nineties of the last century, Russians proposed a new concept of combined propulsion system which was composed of a turbine and an MHD enhanced scramjet for hypersonic cruised aircraft. Later, they established the AJAX program [4]. The most innovative and key issue about this program was the utilization of MHD system to develop an MHD bypass scramjet technology, and to control the inlet of the propulsion system. According to the AJAX program, the inlet control can be furnished by an MHD device through the modification of the external flow upstream of the scramjet inlet. It helps in improving the performance of engine at off-design conditions [3][4][5][6]. The governing equations for MHD include the conservation laws of fluid dynamics augmented by terms including magnetic effects and Maxwell's equation of electrodynamics. It forms an eight-wave model demonstrating the strong interaction between the flow field and electromagnetic field. This system of equations is not strictly hyperbolic since eigenvalues of the system may coincide, causing the system to be nonconvex [7,8]. Due to these mathematical characteristics, the algorithms implemented on Euler equations do not guarantee the solution of the eight-wave equations.