Throughflow analysis of secondary flow aerodynamics in cold slinger combustion chamber with parallel grid method

Abstract

The throughflow analysis is indispensable for designers in the early stage of gas turbine engine development. However, only a little attention is paid to the combustion chamber in previous relevant researches. The dilution hole in the slinger combustion chamber hasn't been studied with an intact geometry considered. In this paper, a throughflow methodology of the slinger combustion chamber based on the circumferential average method (CAM) is established. The parallel grid method is proposed to simulate the flow both in the dilution hole and between two neighboring dilution holes. For the same region of the meridional plane relevant to the dilution hole, two separate sets of grids are involved to simulate both flow structures and the flow combination occurs at the indicative position of the dilution hole outlet. The velocity acceleration process in these two positions can be grasped more exactly. The spanwise distribution tendency of the Mach number and the density flow at the flame tube outlet is similar to the Fluent results. They are higher in the middle and lower at both ends, which is consistent with the correct physical knowledge. The residual of this combustor simulation can arrive at nearly 10⁻⁴ and it costs only 20 min to get convergent. The convergent feature of the mass flow is improved drastically compared with results from the Nigmatullin method in CIAM. The relative fluctuation range of the inlet mass flow is decreased from 1.5 % to 0.008 % and the outlet mass flow is reduced from 4.2 % to 0.005 %.