The naphthalene sublimation technique is used to investigate the effect of freestream turbulence (Tu up to 8.5%) on the mass/heat transport from a turbine blade's suction and pressure surfaces in a high performance turbine blade cascade. The experiments are conducted in both two and three dimensional flow regions on the blade for Reynolds number based on chord and exit velocity of 5.2 × 105. Laminar boundary layers are found over most of the blade surfaces due to high flow acceleration in the passage. High freestream turbulence causes earlier boundary layer transition and significantly enhances the mass/heat transfer. For the laminar and turbulent boundary layers on the blade, the influence of freestream turbulence is small. Taylor-Görtler vortices, found for low freestream turbulence, disappear in the presence of elevated freestream turbulence on the pressure surface. Near the endwall, the area affected by the secondary flow is reduced to some extent on both the suction and pressure surfaces with increasing turbulence level.
|Original language||English (US)|
|Number of pages||8|
|Journal||International Journal of Heat and Technology|
|State||Published - Jan 1 1998|