【摘要】 采用流体体积分数的混合型多流体数值模型,将piecewise parabolic method(PPM)方法应用于可压缩多流体流动的数值模拟,拓展了以前提出的模型和数值方法,使它能够处理一般的Mie-Grüneisen状态方程。采用双波近似和两层迭代算法求解一般状态方程的Riemann问题;并根据多流体接触界面无振荡原则设计高精度计算格式,对典型的纯界面平移问题可以从理论上证明本算法在接触间断附近压力和速度没有振荡,而且数值模拟结果表明界面数值耗散也被控制在2~3个网格之内。模拟了多种复杂的可压缩多流体流动,算例结果表明本文方法可以有效地处理接触间断、激波等物理问题,且具有耗散小精度高的特点。更多还原

【Abstract】 A compressible fluid-mixture model based on the volume fraction is introduced and a high-order piecewise parabolic method(PPM) is employed to solve the multi-fluid flow which are characterized by the Mie-Grüneisen equation of state.The double shock approximation and two level iteration algorithm are used to solve the Riemann problem for general equation of state.A new high resolution scheme is proposed for the mixed type multi-fluid model,which satisfies the principle of oscillation-free for pressure and velocity near the interface between different fluids.For a pure interface problem,the proposed scheme is oscillation-free,and the numerical results also validate that there is no any spurious oscillation in the pressure as well as in velocity profiles on the contact discontinuity while numerical diffusion is limited in two or three cell grids,which is much better than state of the art algorithms.Some numerical experiments and comparisons are presented,and the numerical results show that the new method can simulate the complicated compressible multi-fluid problem such as high pressure ratio Riemann problem,shock-interface interaction and so on.更多还原