Design Analysis of a Satellite Hydrazine Propulsion System

Numerical simulations are conducted to study various features of the key design parameters for a hydrazinebased satellite propulsion system. For the steady-state e uid analysis, a e ow-channel network numerical scheme is used to determine the blowdown proe le and the pressure drops in the propellant line, as well as the blowdown characteristics during theoperation lifetimeofthepropulsion system. For the transient e uid analysis,a theoretical model based on the method of characteristics is solved to simulate the time-dependent transport behavior of the propellante ows.Thepressureresponsesattheinletsofthelatchisolationvalveandthrustervalvesfortheconditions of different thrust force levels, different equipping orie ces, different pipeline lengths, and different open/closed periods in 0.25-s control cycle were studied. Predicted results indicate that better blowdown behaviors can be obtained for a satellite employing a bigger tank because the e xed propellant mass was loaded to the propulsion system. Better performances can also be achieved for smaller thrust level thrusters used on the satellite. When an appropriate orie ce is equipped into the pipeline, the pressure e uctuation can be damped out rapidly and the potential risk of damaging the propulsion components is minimized. An optimum thruster valve opening time of 80 ms for the pulse-mode control is also recommended.