Aero-Thermodynamic Modelling and Gas Path Simulation for a Twin Spool Turbo Jet Engine

The user community of civil and military aircraft powered by gas turbine engines has a significant interest on simulation models for design, development and maintenance activities. These play a crucial role in understanding the aircraft mission performance. The simulation models can be used to understand the behavior of gas turbine engine running at various operating conditions, which are used for studying the aircraft performance and also vital for engine diagnostics. Other significant advantage of simulation model is that it can generate required data at intermediate stages in gas turbine engine, which sometimes cannot be obtained by measurement. Thus engine simulation model / virtual engine building is one of the important aspects towards development of Engine Health Management (EHM) system. This paper describes in detail the engine simulation model development for a typical twin spool turbo jet engine using commercially available Gas turbine Simulation Program (GSP). The engine simulation model has been used for typical aero-engine to get aero-thermodynamic gas path performance analysis related to engine run at Design point, Off Design points and the engine Acceleration-Deceleration Cycles (ADC). Simulations at different operating conditions have been carried out using scaled up characteristic maps of engine components. Design point data as well as engine gas path data obtained from test bed has been used to develop scaled up characteristic maps of the engine components. The simulation results have been compared with various test bed data sets for the purpose of validation. Predicted results of engine parameters like engine mass flow rate and thrust are in good agreement with the test bed data. This validated model can be used to simulate faulty engine components and to develop the fault identification modules and subsequently an EHM system.