Performance Increases for Gas-Turbine Engines Through Combustion Inside the Turbine

In a conventional gas-turbine engine, fuel is burned in separate combustors before the heated high-pressure gas expands through the turbine to provide shaft power for the compressor, fan, propellers, helicoptor rotors, or an electric generator in a ground-based powerplant application. It is proposed in this paper that combustion be continued purposely inside the turbine to increase the efficiency and specific thrust/power of the engine. We term such a turbine with combustion a turbine-burner. A thermodynamic cycle analysis is performed to demonstrate the performance gains of turbojet engines with the turbine burner over the conventional turbojets. Ground-based gas-turbine engines for power generation are also analyzed, with the results showing even better performance gains compared without conventional engines. A mixing-layer analysis with combustion in an accelarated flow similar to the conditions in the turbine burner shows that there is also potential reduction of NOr by using the turbineburner compared with conventional combustors, where the burning is at a constant pressure. Challenges and related research issues that must be addressed to use the turbine-burner technology are identified in this paper.