Influence of complex inlet conditions on the flow field and flow characteristics in compact combustor for gas turbine

Abstract

The interstage turbine burner can improve the compactness of the engine structure and increase the thrust–weight ratio of the engine without using afterburner. Achieving this goal requires stable combustion within a very short distance after the high-pressure turbine. It is necessary to study the flow field structure in the interstage turbine burner. In this study, numerical simulation was used to investigate the flow field structure and flow characteristics in the combustor. The influence of the inlet residual swirl and the radial distribution of the inlet flow velocity on the flow field structure, the proportion of the mainstream and secondary flows, and the flow loss of the combustor under different inflow conditions was obtained. The analysis of the numerical simulation results showed that the influence of inlet residual swirl on the total pressure loss coefficient showed a positive correlation trend, but within a range of 4500–6000 revolutions per minute (rpm), swirl would minimize the total pressure loss coefficient. Residual swirl has a significant impact on the strength and circumferential spatial distribution of primary and secondary vortices within the combustor, while the radial velocity distribution has a lower impact on the vortex structure within the cavity, but it has a certain influence on the total pressure loss coefficient and the proportion of the mainstream and secondary flows. At 0.315 Mach number (Ma), the total pressure loss of the faster inside radial distribution of the velocity is reduced by 1% compared to a uniform inlet.