Numerical investigation on the effect of hot running rim seal clearance on hot gas ingestion into rotor-stator system

摘要

The effect of hot running rim seal clearance on hot gas ingestion, the cooling effectiveness of the rim seal, and the temperature rise in the turbine disc are studied in this work. The conjugate heat transfer method is used to solve the heat transfer in a turbine disc, which is determined by the boundary layer in the cavity and the thermal conductivity of disc. The temperature and deformation of the elastic body of the high pressure turbine disc are solved in multi-physics fields. The radial growths of the turbine rotor disc are approximately 11.89-18.11% of the turbine platform thickness, resulting in a "new" hot running rim seal clearance. The hot running rim seal aggravates the ingress and egress behaviors because of the increased pressure difference in clearance, leading to extra ingestion into the cavity with a 2.35-6.77% decrease in cooling effectiveness, and an increase in the stator disc surface temperature of 16.5-62.2 K. For the cooling air system, the hot running clearance consumes extra cooling air to make up the cooling effectiveness difference resulting from the marginal effect of cooling air. This substantial performance penalty is unexpected.