背景太阳风数值模拟的嫡守恒格式

Background solar wind is a key factor for interplanetary disturbance propagation. Magnetohydrodynamic (MHD) simulation is an important tool for background solar wind study. In this paper an entropy conservation scheme is adopted. Ideal GLM-MHD is used to handle the magnetic divergence. The divergence of the magnetic field generated during the calculation is propagated outside the calculation domain with the maximum characteristic speed of MHD system. With the analytical divergence-free condition of magnetic field as additional constraint condition, the reconstruction of solution variables uses the constrained least squares method. The reconstructed magnetic field gradient is further modified by the way of iteration. The flux calculation adopts an entropy conservation scheme which satisfies the second law of thermodynamics. This formulation can ensure that the entropy does not increase in the calculation process, and the numerical stability can be guaranteed. The results show that numerical simulation for solar wind background by entropy conservation scheme can obtain more stable results.