Toshihiko Asami

Numerical Simulation on the Growth of Hot Gas Spots produced by Composite Sparks.

The formation process of hot gas spots produced by composite sparks including a capacitive discharge component and an inductive discharge one has been investigated by a numerical method. In the simulation, the spark discharge was modeled as heat generation of fluid by the capacitive discharge energy and the inductive discharge one. Then fully compressible Navier-Stokes equations with an unsteady heat generation term were solved numerically. The calculated results indicate that the convection field formed after the propagation of the pressure wave is important for the growth of hot gas spots and the capacitive component plays a major role in forming the convection field. The temperature of hot gas spots is maintained by the subsequent inductive component. These results were confirmed qualitatively by experimental visualization of the thermal field.