Cooling effectiveness in a rotor-stator system with different pre-swirl angles

An experimental study of the flow and heat transfer characteristics in a pre-swirl rotor-stator system was described. Pre-swirl cooling air through nozzles in the stator flowed radially outwards and left system from the clearance between rotor and stator. Three kinds of pre-swirl nozzles (orifice angle of inclination at 0°, 15°, and 30°) were applied to study cooling effects of pre-swirl flow on the rotating disk. Some parameters including distributions of temperature, local and averaged Nusselt number, dimensionless excessive body average temperature and dimensionless radial temperature difference were measured in the tests. It shows that the nozzle with 0° angle of inclination has the highest cooling effectiveness, followed by the 15° nozzle and then the 30° nozzle. The cooling flow rate plays a more important role on cooling effectiveness than rotating speed.