Mesoscale responses of plastic boned explosives (PBX) and grannular HMX under shock loading were investigated with discrete element method(DEM). It shows that for shocked grannular HMX temperature and pressure in grain boundary are much higher than those of inner HMX crystals. In the case of shocked PBX high temperature and pressure regions are mostly located in binder and near parts. Comparisons show that temperature and pressure in grain boundary are effectively reduced by binder.

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.

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.

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.