A Simulation Algorithm for Staged Combustion Cycle Liquid Propellant Rocket Engines

In order to reduce cost and time along with enhancing the safety issues, numerical computer modelling and simulations are widely used for analyzing complex systems such as launch vehicle or spacecraftpropulsion system. The objective of this research is toobtain an algorithm for simulation of staged combustion cycle liquid propellant engines. For this purpose the space shuttle main engine (SSME), as oneof the world’s most complicated engines, is selected asa case study. A total of 34 elements is taken into account and using more than 100 linear/non-linear equations, the engine’s steady state system model hasbeen established in MATLAB SIMULINK software. The simulation method uses eleven nested loops for iteration. The algorithm is based on the known parameters at the inlet of engine main feed linesnamely mass flow rate and pressure, similar to the known conditions during hot test of engine on test stand. The simulation is capable of predicting the engine’s operation in wide range of thrust throttlinglevels from 69 percent to 109 percent of the nominal thrust. In order to validate the suggested method, SSME main component parameters, operating at 109 percent of rated thrust is presented. Simulation result mean error is less than 5 percent.