A simulation model for the working process of rocket engine combustion chamber was described. Simulation was implemented by using this model for a 10N thruster working at different lower supply pressures. Comparisons were made to find some characteristics of chamber pressure and thrust of the thruster when it worked in long-pulse and short-pulse modes at regular and lower supply pressures. According to the theoretical thrust obtained by simulation and the experimental thrust in long-pulse mode

it can be concluded that the thrust efficiencies are 94%

91% and 90%

respectively

while supply pressures equal to 1.48

1.0

0.6MPa

separately. Meanwhile

simulation results of short-pulse mode cases show that

when the supply pressure decreases to 0.4MPa

the thruster cannot be ignited in short-pulse mode.