Flow field and combustion characteristics of integrated combustion mode using cavity with low flow resistance for gas turbine engines

Structural weight and flow resistance of the combustor were important parameters affecting the overall performance of gas turbine. The integrated combustion mode and trapped-vortex combustion mode were the means to fulfill these requirements. Components integration of combustor was an important trend in the development of the combustion technology. In this paper, the trapped-vortex combustion mode was combined with integrated combustion mode, and a new type of integrated combustor with various cavities was proposed. By integrating the flameholder with the structural strut, light weight of the structure could be achieved. By adopting trapped vortex combustion mode, high combustion efficiency could be obtained in wide range of inlet velocity and fuel-air ratio. Using the particle image velocimetry and experimental system, the flow field and combustion characteristics, including ignition, combustion efficiency, outlet temperature distribution and wall cooling characteristics, were thoroughly analyzed. Fuel droplets injected by simple nozzles could be evaporated and mixed with mainstream air in a short distance. The feasibility of the novel combustion mode was completely verified. Low flow resistance and high combustion efficiency was achieved, which was difficult for the integrated combustion mode. The results were beneficial to the research of high performance gas turbines with compact structure.