Transient state flow and heat transfer performance over the flat tip of HP turbine

Abstract

To study the flow and heat transfer performance over the flat tip of high pressure (HP) turbine under transient conditions more accurately, a dynamic boundary condition model from one stable operating state to another stable operating state is established. The changes of model include inlet total temperature, inlet total pressure, inlet flow angle, and tip clearance. Furthermore, the steady-state solution is performed at the typical moments of the transient state, to study the feasibility of steady state replacing transient state performance. The results show that the heat transfer performance of the blade tip under transient conditions mainly focus on the pressure side. The separation vortex formed at the edge of the pressure side significantly affects the distribution of the heat transfer coefficient. The flow and heat transfer performance obtained under steady-state conditions are close to those under transient conditions. The maximum deviation of heat transfer coefficient and total pressure recovery coefficient at each typical moment does not exceed 0.1%.