چكيده به لاتين
Nowadays, turbofan engines are used to provide the propulsion in commercial aircrafts. High efficiency, less specific fuel consumption (SFC) and achieve to higher speeds in comparison with propeller engines in flight conditions, have attracted a special attention to this type of aero-engines. Because of costly laboratory testing of turbofan engines, modeling of them has been of a great importance. To construct a comprehensive engine model, apart from an accurate modeling of the thermodynamic cycle, operating conditions of the engine is of a great importance as well. Hence, flight conditions of the engine must also be modeled precisely. All aero-engines have some physical and practical limitations which could be satisfy by means of an appropriate controller design. This can also optimize fuel consumption. To avoid instability in the compressor and high pressure turbine inlet over-temperature, bleed can be applied. To do this, modeling of the aero-engine could be performed considering compressor stage-by-stage characteristics and thereby specify the location and quantity of the bleed.
In this thesis, modeling and performance control of a turbofan engine using stage-by-stage characteristics of the compressor in flight conditions have been performed. In this way, to simulate flight conditions, some concepts like flight envelope and flight path have been adapted. Related flight envelope has been derived using the commercial software of Gasturb and the flight path has been obtained using flight engineering bureau information. Some related informations from aircrafts like Airbus 320 and Boeing 737, which their engines are similar to the current engine, have been extracted and used to simulate flight conditions. In this thesis a stage-by-stage thermodynamic model of IR59-MT-X turbofan engine has been used. The bleed algorithm for this engine has been added to the Simulink model on an open loop manner. Then, Min-Max algorithm has been used to calculate required engine fuel. To find the optimum controller coefficients in standard and flight conditions, generic algorithm has been used. Finally, the results of the modeling and performance analysis of the Min-Max controller due to mach number, altitude and PLA input signals have been presented which demonstrate no violation from the allowable limits and the achieveness of the required thrust.
Keywords: Turbofan Engine, Min-Max Control Algorithm, Genetic Algorithm, Compressor Stage-by-Stage Modeling, Flight Conditions.
