Numerical Study Of The Interaction Of Shock Wave And The Interface Of Material On Cartesian Grid

The interactions of shock wave and the interface of multi-material have broadapplications in engineerings. It is involved in aviation, spaceflight, sailing, nuclear energy,materials, celestial mechanics, biomedicine and many other fields. The dynamic response ofmaterials to high speed flows and high intensity loading conditions due to shock anddetonation waves is important in several applications including high-speed flows withdroplets, bubbles and detonation diffraction. In such high pressure physics problems, there arecomputational challenges associated with the treatment of material interfaces, particularlywhen strong nonlinear waves interact with the interfaces, waves reflection, refraction anddiffraction occurs at the interface, with large interfacial deformation. It shows the interactionof shock and material interface is an extremely complex process.In this thesis, a Cartesian grid method in conjunction with Level set interface tracking isused to simulate both multi-fluid and complex boundary problems. A new method Wall GhostFluid Method (WGFM) is developed for resolving solid (rigid) objects based on the realGhost Fluid method (rGFM). Introducing a switching variable, the rGFM and WGFM can beexpressed in a single framework, which is named rWGFM. And this method is applied for theproblem of multi-material interface in which the interface defines a complex, static or movingboundary between the fluid and a rigid solid wall or a body. And the HLLC-HLL scheme isextended for compressible multi-material flows with Cartesian grid, it is tested against theproblems of interaction of shock and the interface of multi-material and spurious solutions inthe strong shock regions are successfully controlled.The following works are performed in this thesis.(1) The interaction of shock andgas-gas interface,(2) The interaction of shock and gas-water interface,(3) The interaction ofshock and fluid-solid interface, and the solid-fluid interface include stationary boundary andmoving boundary,(4) The interaction of shock and interfaces of fluid-fluid and fluid-solid.For research problems, including shock and gas bubble interaction problem, shock andcylindrical droplet interaction problem, collapse of gas bubble under shock in water andunderwater explosion, shock diffraction over a rigid body and high-speed rigid body motionproblem, the reciprocity between shock wave, material interface and many kinds ofdiscontinuities is captured clearly, the simulation result is according with that in corresponding literature.The research results would give better understanding in the physical problems. And itcan be taken as a basis for further study.