Numerical investigation of initial condition of high pressure underexpanded methane injection into still air

Numerical simulations are carried out for an underexpanded methane jet resulting from high pressure reservoir into atmospheric environment. Multi-dimensional simulations are used to analyze the penetration and mixing of methane jet to the atmosphere. The capability of multidimensional numerical simulations, based on the k-w turbulence model, to reproduce the experimentally verified pressure distribution of free jet is evaluated. Effect of pressure ratio and exit Mach number on the pressure profile are shown. The paper discusses factors affecting the concentration of the methane, in particular, the pressure and exit Mach number conditions. The sensitivity of mach disc location during injection to the variation of pressure ratio was decreased while to exit Mach number increased.

Keywords:

high pressure injection , mach disk , under expanded jet , numerical simulation