Characteristic analysis of supersonic impinging jet in laser machining

Abstract

The interaction of a gas jet with a workpiece in laser machining is investigated by studying the influence of the processing parameters on the dynamic characteristic of the gas flow in the hole, mainly including the mass flow rate and the thrust. The modeling of a supersonic turbulent jet impinging on a plate with a hole concentric with the jet is presented. Numerical simulations are carried out using an explicit, coupled solution algorithm with solution-based mesh adaptation. The model is able to make quantitative predictions of the effect of the standoff distance on the mass flow rate and the axial thrust. It is revealed that the shape of the hole has weak effects on shock structure, but it can improve the dynamic characteristic slightly. The standoff distance has great effect not only on the shock structure, but also on the jump and fluctuation of the thrust for the different exit Mach number.