Srinivasan, T. D.

Accurate representation of the dynamic behaviour of the Space Shuttle Main Engine (SSME) is required for various diagnostic, design and evaluation purposes. A complete nonlinear dynamic simulation of the SSME developed by the Rocketdyne Division of the Rockwell International Corporation is difficult to use due to its size and complexity, hence the need to obtain a simplified model of the SSME to generate data describing the normal modes of operation in real time is relevant and also the objective of this thesis. The process involved in obtaining such a model are: (1) To determine the point models at various operating points and (2) To obtain a comprehensive piece-wise linear model by regressing the parameters of the point models with variables describing the operating points. The comprehensive model obtained by using such a scheme is presented along with the point models. The nonlinearities inherent in the engine's operation are modelled as separate blocks and are added to linearized model. Finally the validity of the linked model is demonstrated with suitable test signals.