SFB 1029: TurbIn - Substantial Efficiency Increase in Gas Turbines through Direct Use of Coupled Unsteady Combustion and Flow Dynamics

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A significant increase of the efficiency of gas turbines is the objective of the CRC 1029 and shall be achieved by changing the combustion concept towards an approximately constant volume combustion. Two concepts have been investigated up to now. While the pulsed detonation combustion bases on an extremely fast combustion triggered by shock waves, it also causes large pressure fluctuations. These are largely reduced by the alternative concept of a shockless explosion combustion, where a specific layering of the fuel and the utilization of acoustic phenomena lead to a homogeneous auto-ignition of the whole combustion tube. The third period of CRC 1029 will additionally include the rotating detonation combustion. Due to pressure waves travelling in circumferential direction at very high frequencies, this concept seems to be very promising for implementation in gas turbines as well.In contrast to conventional gas turbine processes, all described combustion concepts feature periodically unsteady pressure waves and will thus have a significant impact on the operating conditions of the turbomachinery components within the gas turbine. Methods and experiments have been investigated to effectively reduce the pressure pulsation at the interfaces between compressor, combustion chamber and turbine. Furthermore, sufficient cooling of the first turbine stage as well as flow stability at the compressor exit must be safeguarded and have thus been further focus areas of CRC 1029. One objective was to reduce the additional effort to a minimum to protect the overall efficiency gain of the whole gas turbine. Within the third period, the developed measures shall be driven towards a higher degree of maturity within relevant gas turbine conditions. For the same reason, the holistic assessment of the engine, which was solely based on well-developed thermodynamic methods so far will now be expanded to look at structural mechanics’ aspects as well.Within the third period, the achieved results of the projects shall coalesce in the setup of a demonstrator platform. It shall serve to develop process control strategies in different load regimes as well as to derive representative boundary conditions for the experiments with dedicated stand-alone rigs of compressor and turbine.