Numerical Study Of The Flow And Heat Transfer In The Rotating Cavity With The De-swirled System

The turbine is a very important bearing strength and high temperature part of an aero gas turbine engine. The main approach to improve the performance of the modern aero gas turbine engine is to raise the temperature of the front of turbine. However, the higher and higher temperature of gas makes higher demand of the cooling mode and structure. So, in order to improve the performance and prolong survice life of an gas turbine, we must intensive study different cooling modes and structures which have different cooling effect to turbine parts.In this paper, numerical simulations were conducted to study the flow and heat transfer characteristics inside co-rotating cavity with de-swirled system. Both steady and unsteady structured grids were used. In order to satisfy the demand of Ekman boundary layer, the specific contents include: (1) Several different turbulence models were applied to the numerical simulation of flow and heat transfer inside the tipical rotor-stator cavity and co-rotor cavity, and the reasonable turbulence model was selected by the comparisons of the calculation results and the experiment data. (2) The reasonable turbulence model was applied in the paper to study the velocity field, temperature field, pressure field and Nusselt number across the cavity under different angles of de-swirled nozzles,the number of de-swirled nozzles, nondimensional flow rate and the rotational Reynolds number and so on. (3) The comparisons of the de-swirl co-rotating cavity and the pre-swirl stator-rotator and both the co-rotating and stator-rotator cavities that have no tangential velocity model were made.(4)Numerical simulations were conducted to study the effect of angular speed ratio, nondimensional flow rate and the rotational Reynolds number to the flow and heat transfer characterics inside co-rotating cavity with deswirl nozzles in which outer shrould.Computational results indicate: The overall pressure drop across the cavity goes down with the increase of the number of de-swirl holes and the de-swirl angle. If decrease the number of de-swirl holes, increase rotational Reynolds numbers and the massflow, the heat transfer is enhanced.The temperature of the gas in outlet 2 is reduced more significant as the increase of the non-dimensional massflow and the number of de-swirl holes, or as the decrease of the rotational Reynolds numbers.Under the same condition, compared with the rotator-stator cavity with radial inflow model and the pre-swirled inlet cavity model, the co-rotating cavity with de-swirled radial inflow model has better heat transfer effects and lower outflow temperature. For the contra-rotating cavity, the angle speed ratio has little effect on the overall pressure drop. Under the rotor-stator cavity condition, heat transfer effect is the worst.