Experimental and Numerical Studies on the Plume Structure of Micro-nozzles Operating at High-Vacuum Conditions

Abstract

Recently micro-thruster-based miniature nozzles are gaining research interest due to the advent of micro-propulsion technology for micro-spacecraft and attitude management requirements of micro- and nano-satellites. Micro-nozzles experience all types of flow regimes from continuum to free-molecular flows when they are operated at high-vacuum conditions. Experimental and numerical analysis of cold-flow plume structure of a typical conical micro-nozzle is presented here. The plume structure is visualized using glow discharge flow visualization (GDFV) technique and surveyed the entire plume axially with a static pressure probe. Numerical modeling of a micro-nozzle operating in rarefied condition is done using a coupled Navier-Stokes (NS)-DSMC method, and the pressure profile of the nozzle plume is compared with that obtained in experiment.