Flow field induced by a moving shock interacted with cylindrical water columns and a nozzle flow field was numerically investigated. Fixed Cartesian grids are used and level-set method combined with revised real ghost fluid method (rGFM) is applied for tracking gas-water and gas-solid interfaces. Fifth order WENO schemes are employed for solving Eulerian and level-set equations as well as reinitialization equations. Nozzle contours are simplified as gas-solid interface, and nozzle contour profiles are expressed by splines for ease of obtaining normal vector. In the case of shock interacting with water columns, schlieren images and pressure time histories at specified points are shown to describe shock evolution and mitigation downstream. It indicates that complex shock structures are distinguished accurately by the method, and shock transmission and reflection occur on gas-water interfaces of neighboring columns in a row and in a column respectively. In addition, pressure, density contours and velocity of nozzle flow field is in agreement with inviscid solution by gas dynamics theory, which demonstrates effectiveness and robustness of level-set method coupling with rGFM for computing flow field in a complex geometry involving gas-water and gas-solid interfaces.

A new free surface scheme for 1-D and 2-D numerical calculation of elastic-plastic flow is proposed to study e-beam or X-ray radiation,high velocity impact and blast.Some numerical examples given here show that the pressent free surface scheme is more suitable than Richtmyer's for solving thermal-mechanical effects of material subjected to e-beam or X-ray pulse radiation.It is proved that this scheme should give a third-order accuracy.

Using Monte-Carlo method, the electon transport and energy deposition in material are calculated. Combining with the elastic plastic hydrodynamic equations, numerical results cover the thermal mechanical effect and the blowoff impulse on Ly-12 Al induced by irradiating of the impulsive electrobeam which caused by ‘FLASH Ⅱ’-an impulsator of relativistic electron beams. these results are compared with the experimental data.

Electron transpart characteristics and energy deposition in the medium are calculated by using Monte-Carlo method. Based on the calculations thermal-mechanical effect on material bombarded by electro-beam can be investigated by solving the coupled fluid-plastic equations. Several numerical simulations of the effect in Al have been carried out as illustration of the present method. Calculated results coincide satisfactorily with the experimental data.