Modeling and simulation of staged comubstion cycle LPRE

Computer modelling and simulations are commonly used for analyzing complex systems such as launch vehicle propulsion system. The main objective of this research is to obtain a mathematical model for simulation of staged combustion cycle liquid propellant rocket engines (LPRE). For this purpose, using modular simulation concept, the engine major components are divided into eight main modules and the governing nonlinear steady state mathematical equations of each module is derived. At the next step, an algorithm based on engine's main feed line inlet parameters is established by which the modules can connected depending on desired engine flow diagram. For case study, space shuttle main engine (SSME) is selected which due to its complexity, can be considered as a comprehensive instance. A total of 34 components is taken into account and using more than 100 linear/non-linear equations, a steady state system model is developed in MATLAB Simulink. The model is capable of predicting SSME operating conditions from 50 to 109 percent throttling level. Comparing the results at 109 percent of rated thrust, it is found that the mean error is less than 5 percent.