Study on the dynamical characteristics of a supersonic high pressure ratio underexpanded impinging ideal gas jet through numerical simulations

The impingement of an axisymmetric underexpanded ideal gas jet on a flat surface is investigated through numerical simulations. Different injection conditions, characterized by the nozzle pressure ratio (NPR), have been considered and for each, several standoff distances were studied. The study was conducted using the commercial finite volume general purpose code Fluent®. The numerical results are presented in terms of Mach number and static pressure to characterize the structure of the flow. Furthermore, the influence of the standoff distance upon the position and diameter of Mach disk is analysed. Some results are compared with literature data and good agreement is obtained.

► Dynamical characteristics of the jet impinging normally on a surface are characterized.
► The effects of NPR and standoff distance upon the jet's structure are investigated.
► High NPR are studied; obtained structure is comparable to that of lower NPR.
► The two parameters influence in a coupled manner the structure of the jet.
► At given NPR, existence of a threshold standoff distance is highlighted.
► Evolution of diameter and position of the Mach disk is shown.
► The mixing layer of the jet can be deflected from jet axis.