Development of thermo-fluid performance tool for propulsion systems

Performance models have an important place in the engine development process in terms of cost and time savings. Performance calculations are processes that require iterative approaches to return to the previous stage if previous assumptions are found to be invalid. For this reason, many engine developers, including companies in our country, benefit from commercial software such as GasTurb, NPSS, GSP. Within the scope of this thesis, performance calculation program has been developed for Turbojet, Turbofan, Ramjet and Scramjet engine configurations. The developed program AEPS ,Aero Engine Performance Simulation, has been designed as modular so that program can be developed more easily in the future. AEPS program basically consists of two main modules as Cold Air Standart Cycle Module, CASC and Real Cycle Module. The CASC Module has been developed based on the cold air standard, where component efficiencies are taken into account, specific heat values are determined by the user, and thermo-physical properties are considered constant. The CASC Module has been developed to allow input of different types of data from different sources and only performs design point calculations. The Real Cycle Module has been developed with reference to the GasTurb14 software. Specific heat, specific enthalpy and temperature dependent portion of entropy are calculated as a function of temperature and fuel-air mixture ratio with the numerical air model included in the program. The Real Cycle Module performs design point and off-design calculations. Component maps selected as references for off-design calculations are used by scaling them according to the design point. The GasTurb14 software calculates the Total Pressure Recovery Factor only as a function of the Mach number in supersonic air intake calculations. This approach neglects the effect of ramp number and ramp angles in the calculation of the supersonic air intake Total Pressure Recovery Factor. In addition to the approach used by GasTurb14, the AEPS program offers the Supersonic Air Intake Module, which uses oblique shock relations, as an alternative to the user. The CASC Module of the AEPS program was validated by running it with different types of propulsion problems selected from different sources and comparing the results obtained with the reference source results. The Real Cycle Module of the AEPS program was run with the demo engine configuration parameters of the GasTurb14 software and the results obtained were compared with the results obtained from the GasTurb14 software. As a result of the comparison studies, it was observed that both the CASC Module and the Real Cycle Module of the AEPS program gave very realistic results.