Film-Cooling Effectiveness of Antivortex Holes at Three Different Mainstream Turbulence Levels

摘要

The effects of mainstream turbulence intensity on the film-cooling effectiveness of antivortex film-cooling holes were experimentally investigated. Four film-cooling hole configurations and three mainstream turbulence intensities (1,6.5, and 16) were tested. The primary film-cooling hole had a 30 deg angle with respect to the mainstream flow, and the angles between the primary and auxiliary holes of the antivortex holes were 0,15, and 30 deg, respectively. The film-cooling effectiveness was measured using pressure-sensitive paint technique. The particle image velocimetry measurement results showed that the coolant from the antivortex film-cooling hole stayed closer to the endwall than that for the cylindrical hole case. The film-cooling effectiveness for the antivortex hole cases was higher than that for the cylindrical hole case for all blowing ratios. For the antivortex hole cases, the coolant-covered area generally increased as the blowing ratio increased. For the high mainstream turbulence intensity case, the higher blowing ratio cases showed greater film-cooling effectiveness due to the dragdown of the coolant Among the tested configurations, the 15 deg antivortex hole case showed the best film-cooling performance at all blowing ratios and turbulence intensities.