Discrete element method combined with undiffused two-phase transition model,thermodynamic consistent Helmholtz free energy function,and phase transition kinetics of relaxation equation are used to simulate α-iron phase transition process.Through simulation of phase boundary,Hugoniot relation and free surface velocity profiles are obtained.Wave interaction in loading and unloading process under different pressures is analyzed.Characteristics of loading and unloading wave velocity are acquired.

A two-dimensional elastic plastic hydrodynamics Eulerian code MEPH is applied to simulate micro-jet formation and penetration process of void in sample during shock loading.We focused on forming process of micro-jet.Maximal penetration depth versus key factors such as shock pressure and void diameter is analysed.Theoretical jet penetration is compared with numerical simulations of maximal penertration depth.

A study on oblique shock wave reflection in condensed matter is carried out by means of numerical simulation and theoretical analysis.Runge-Kutta control volume discontinuous finite element method is used to solve Euler equations.Equations of state for condensed matter adopt "stiffen gas" formulas.Patterns of oblique shock wave reflection in condensed matter are discussed.A shock polar theory is employed in analyzing critical agles of transition from regular reflection to irregular reflection.It gives states of reflected shock wave.Numerical results and shock polar solutions are compared and typical oblique shock wave reflections are obtained.

Theoretical study and numerical simulations are made on size distribution characteristic of initial liquid drops during aerosol explosive dispersal process.With thermodynamic consistent concept,the maximization of entropy generation in the initial breakup process,constraint equations of the problem are derived,and probability distribution function of initial drop size is obtained.Numerical predictions are in agreement with air-blast annular nozzle experimental data and Samirant experimental data.

A two-dimensional elastic and plastic hydrodynamics code MEPH is applied to simulate ejecting process. We focus on the effect of shock pressure and shock risetime on mass ejection from shocked aluminum. It shows that with increase of shock pressure the ejecting factor keeps increasing, but the ejecting factor is not sensitive to the shock pressure. The effect of shock risetime on the mass ejection from shocked aluminum is also investigated. Numerical results agree well with experiments. The mass ejection is sensitive to shock risetime.

A two-dimensional elastic and plastic hydrodynamics Eulerian code MEPH is applied to simulate aluminium ejecting with single defect.We focus on change of maximum ejecting velocity and ejecting factor with different angle and shape.Numerical results are consistent with experiments.

We study asymmetric jet and slug formation in collision of two plane flows at a finite distance from stagnation point. Analytic expressions for width and flow direction of jet and slug are given on a solution ellipse. The jetting process is simulated with Euler hydrocode of high order precision and YOUNGS algorithm for tracking interfaces. Predictions are more accurate than results of other analytic models and are in agreement with KS experimental data. With increase of asymmetry between incoming flows, flow direction of slug changes considerably, whereas the direction of jet barely deviates from the direction of symmetric bisector of incoming flows.

Numerical simulation of spherically imploding detonation waves in hydrogen-oxygen is carried out in an elementary chemical reaction model.Compared with numerical results of imploding shock waves in nitrogen,the discrepancies of gas dynamic characteristics between shock and detonation waves are investigated during implosion.The effect of chemical reactions,combustion and dissociation on detonation waves is revealed.As the wave fronts converge toward the center of symmetry,the front pressures at different radii are almost the same in the two cases.However the front temperatures are different.The temperature increases more rapidly in nitrogen than in hydrogen-oxygen mixture.Higher temperature is reached near the focal point in nitrogen due to its higher dissociation temperature.The energy released at the wave front is negligible in predicting pressure,while it needs to be considered in predicting temperature.