Simulation Study of the Swirl Spray Atomization of a Bipropellant Thruster under Low Temperature Conditions

The spray atomization of an injector significantly influences the performance and working life span a bipropellant thruster spacecraft. Deep space exploration requires to be able operate reliably at low temperature range from −40 °C 0 °C, so effect conditions on characteristics is motivated comprehensively investigated. To study swirl MMH (methylhydrazine), which more difficult atomize than NTO (nitrogen tetroxide), numerical simulations were conducted, employing methods VOF (volume fluid) LES (large eddy simulation) under conditions. physical model with nozzle size 0.5 mm boundary velocity inlet 3.89 m/s both follow actual operation thrusters. development temperatures was observed through parametric comparisons, such as velocity, liquid total surface area, droplet particle distribution, cone angle breakup distance. When decreased 20 same condition flowrate inlet, those propellant vary following these rules: ejection reduced by 7.7%, gas-liquid disturbance sequentially decreases; film stable, negative influence quality, causing difficulties for primary secondary breakup, area droplets also decreases 6.4%; spatial distribution characteristics, distance less 5%. Therefore, can directly lower combustion efficiency thrusters obvious degradation, but there are no significant changes in mixing cooling. It concluded that work around deep probe operation.