Numerical Simulation of a Supersonic Jet Impingement on a Ground

An impingement of axisymmetric supersonic jet on the ground is simulated numerically to evaluate the jet flow configuration on the ground, which inclines from 0 to 45 degrees, with a real gas assumption for two-dimensional simulations and with an ideal gas assumption for three-dimensional simulations. A solid particle-suspended two-phase jet impinging on the ground is also solved using the Euler equations for the solid particle-phase with a real gas assumption. An explicit TVD-Upwind scheme is used for the gas-phase and an explicit Flux Vector Splitting Upwind scheme for the solid-phase.

Numerical results of a vertically impinging jet to the ground show that a plate shock forms just above the ground for the cases of the single-phase and two-phase jet. Then the jet flow is curved along the ground after hitting the ground to form the so-called wall jet, which is expanded and recompressed alternately along the ground. The solid particles hit and stay on the ground in the present system. When the ground inclines, the gas temperature at the stagnation point becomes high due to solid particles.

An experimental study of the underexpanded axisymmetric supersonic N₂ jets impinging on a ground which inclines from 0 to 45 degrees is also discussed. Pressure measurements on the ground surface and Schlieren photometries are performed to investigate the impinging jets. The results show that the maximum pressure on the inclined ground is larger than that on the perpendicular ground due to the possibility of high pressure recoveries through multiple shock systems.