电磁驱动高能量密度动力学实验的一维磁流体力学多物理场数值模拟平台:SSS-MHD

SSS-MHD:a one-dimensional magneto-hydrodynamics multi-physics simulation platform for magnetically-driven high-energy-density dynamics experiments

超高压、超高密度物质状态生成和性质研究是当代极端物理学的重要前沿领域,电磁驱动的高能量密度物理实验对于该领域的意义尤为重要。这类实验虽然形式上多种多样,但在物理上有内在统一性,即均以力学守恒定律和宏观电磁理论为基本框架。为了建立统一数值模拟平台、依靠负载电流实验数据(或驱动电路真实数据)确定各种极端实验条件下负载构形的力学运动及其与各个物理场的耦合问题,将经受大量实际检验的冲击、爆轰动力学和激光效应计算的一维拉格朗日编码SSS,实质性扩展成为磁流体力学多物理场耦合编码SSS-MHD。对于具有典型意义的平面准等熵斜波压缩、高速平面固体飞片发射、固体套筒电磁内爆和炸药内爆磁通量压缩实验等各类高能量密度动力学实验案例的模拟计算结果表明,编码SSS-MHD计算与美国Z装置、中国CQ和CJ系列装置的实验及美国编码ALEGRA-1D和2D计算数据的相对偏差基本不超过5%。该数值模拟平台为极端材料动力学实验(包括气体、液体、化合物和金属)提供了有力的支撑,还将有助于多维磁流体力学多物理场编码的开发。

The research on generation and properties of materials under ultra-high pressure and density constitutes an important part of the extreme physics and hence a field of modern frontier science,especially the magnetically-driven highenergy-density physics herein is meaningful and in great need by core technologies.High pulsed power devices with tensmegampere output current and thousands-Tesla magnetic field were developed in past decades,e.g.,the Z machine capable of 30 MA and 100 TW on load at the Sandia National Laboratories,USA;also a record intense magnetic field of 2800 T achieved with a cascade magneto-cumulative generator of MC-1 type at VNIIEF,Russia.It is available now to compress heavy metals up to 1 TPa or to launch thin Al flyer plates to super high speed over 45 km/s using isentropic compression experiments on the Z machine.Although these experiments take various forms,they have intrinsic unity in physics,which is based on the conservation laws of mechanics and the macroscopic electromagnetic theory.Therefore,it is feasible and necessary to establish a unified numerical simulation platform and determine the mechanical motion of the load configuration and its coupling with various physical fields under extreme experimental conditions by relying on the load current data(or the real data of the drive circuit).The magneto-hydrodynamics multi-physics codes have been successfully developed in USA,e.g.,the excellent performance codes—ALEGRA series at the Sandia National Laboratories.This paper substantively extends the onedimensional Lagrangian code SSS,which has been extensively validated by shock,detonation and laser radiation effect simulations,into a magneto-hydrodynamics multi-physics one and now it is renamed as SSS-MHD.The simulation results of various high-energy-density dynamic experiments with typical significance,such as planar quasi-isentropic ramp wave compression,ultra-high speed solid flyer launch,solid liner implosion,and explosively-driven magnetic flux compression,indicate that their relative deviations of the SSS-MHD simulations from the experimental data of America’s Z machine,China’s CQ and CJ series devices,and ALEGRA-1D/2D calculations are generally less than 5%.The SSS-MHD code turns into a powerful platform to simulate experiments of extreme material dynamics(including gases,liquids,metals and compounds)and its practice could be helpful to develop advanced multi-dimensional MHD multi-physics codes.