Shock therapy was introduced in 1980 to treat kidney stones, and after a while was accepted as one of the best treatment. In this treatment shock waves are used to fragment the kidney stone. Different models of the lithotripter have the same pulse pressure profile but their pulses amplitude make the difference. In this study, the goal is to perform a simulation of the process for a standard lithotripter by considering the expansion of a high pressure vapor bubble generated by an electrical discharge within a reflector and determining the pulse pressure profile of the shock wave. For this purpose, an Arbitrary-Lagrangian-Eulerian (ALE) scheme based on an exact solution of the Riemann problem is used to integrate governing equations in time over a moving grid. Also, a suitable cavitation model has been used in the simulation that can predict the occurrence and collapse of cavitation bubbles as a result of the expansion and compression waves in the liquid phase. The obtained numerical results are compared with experimental results for the validation. Then, simulations have been done for other geometries to study the effect of geometrical parameters on the generated pressure pulse. At the end, the progress has been made so far for constructing an experimental prototype of a lithotripter in our lab is reported. Keywords: Shock wave, Electrohydraulic Lithotripsy, Cavitation, Vapor bubble, ALE scheme
