Experimental Investigations on Isothermal Swirling Flows in a Reverse Flow Annular Gas Turbine Combustor
An experimental work was carried out on confined swirling flows under non-combusting conditions in a reverse flow annular gas turbine combustor. Flow measurements with a five hole pitot probe are carried out in a flow apparatus of a geometrical configuration similar to the model of a swirl combustor. Mean flow results are obtained for different flow conditions to determine the effect of swirl on the recirculation zone and the variation of the swirl strength along the axis of the gas turbine combustion chamber. The boundaries of the recirculation region are plotted to compare the size and length of the zone with various swirlers. Minimum flow Reynolds number is required for flow recirculation; the effect of Reynolds number on determining which flow class is present for flow of interest in combustion chamber was investigated. The inlet swirl number is optimized for higher swirl strength and the inlet swirl number for which recirculation completely vanishes is also estimated.