EXPERIMENTAL INVESTIGATION ON THE FLAT-PLATE FILM COOLING ENHANCEMENT USING THE VORTEX GENERATOR DOWNSTREAM FOR THE CYLINDRICAL HOLE AND FAN-SHAPED HOLE CONFIGURATIONS

摘要

In our experiments, the film cooling performance of the configurations combined the different hole with the vortex generator was investigated experimentally, measured by the infrared camera. Four different configurations were studied at the blowing ratio varying at M=0.5, 1.0, 1.5, 2.0, 2.5 and 3.0. In all cases, the Reynold number of the mainstream based on the hole diameter remained at Re=8000, and the density ratio kept at DR=1.7. Experimental results show that for the two models combining the cylindrical hole and fan-shaped hole with the vortex generator respectively, the film cooling performance becomes better when the blowing ratio increases from M=0.5 to M=2.0, and then decreases when the blowing ratio increases from M=2.0 to M=3.0. The model combining the fan-shaped hole with the vortex generator performs the best among the four models at each blowing ratio. Its film attachment holds the most extensive lateral distribution and its overall film cooling effectiveness could keep at a high level at a wide range of blowing ratios from M=1.0 to M=3.0. The combined model of the fan-shaped hole could improve the area-averaged film effectiveness at most 25.5% than that of the single hole model at M=2.0. Moreover, the combined model of the cylindrical hole could improve the area-averaged film cooling effectiveness at most 431% than that of the single cylindrical hole model at M=3.0.