LAUSR

The transition from regular to irregular reflection when the expanding shock waves generated by underwater electrical wire array explosion collided with each other was investigated using the numerical method. Shadowgraph diagnostics were applied for imaging of the expansion of exploding wires and the propagation of shock waves, and the results agreed well with the self-consistent hydrodynamic simulations based on the cylindrical piston model. The simulation results show that the transition angle from regular to irregular reflection for strong shock is smaller than weak shock, which is the principal cause of the self-alignment phenomenon in the convergence process of stronger shock waves. Also, the nonlinear superposition of pressure peak behind shock wave, caused by the formation and interaction of Mach stems, is analyzed using the oblique shock wave theory.