| A higher temperature flow from an aero-engine combustor needs a higher cooling technology for turbine. One widely used cooling method is gaining some air from the compressor, some of it is used for cooling the turbine blades and nozzle guide vanes, and part of it is employed to cool and seal the turbine discs. So it is very important for cooling to master the rule of the flow field in turbine discs air-cooling system.The numerical simulation and experimental investigations have both been applied to study the flow characteristics inside a very special high-pressure rotating cavity with micro-turbine (de-swirl nozzles). The five-hole probe system was used to measure the velocity of the flow and two-dimensional axisymmetric solver, incorporating the K- ε two equations turbulence model, was used to compute the flow. The distributions of velocity, vortex and pressure coefficient inside the rotating cavity were summarized respectively under five rotational speeds (50rpm, 300rpm, 800rpm, 1300rpm, and 1700rpm), three inlet mass flow rates and six axial locations.Through the experiment it indicates that the flow structure inside the rotating cavity was mainly controlled by rotational speed and not by flow rate. The distributions of no-dimension tangential velocity, vortex structure and static pressure coefficient are given in the paper. The controlling-theory of flow is also proved, namely, the flow is mainly controlled by the inflow effect at lower rotating speeds (50rpm and 300rpm), and by rotating effect at higher speeds (1300rpm and 1700rpm), by both factors at transition speed (800rpm).The computation data accords closely with that of the experiment, also there are some differences between them. It agrees well for their no-dimension tangential velocity under low speeds, for vortex structure under high speeds, and for static pressure coefficient under transition speed. |
