Hot-wire anemometry measurements of simulated film cooling are presented to document the influence of the freestream turbulence intensity and film cooling hole length-to-diameter ratio on mean velocity and on turbulence intensity. Measurements are taken in the zone where the coolant and freestream flows mix. Flow from one row of film cooling holes with a streamwise injection of 35° and no lateral injection and with a coolant-to-freestream flow velocity ratio of 1.0 is investigated under freestream turbulence levels of 0.5% and 12%. The coolant-to-freestream density ratio is unity. Two length-to-diameter ratios for the film cooling holes, 2.3 and 7.0, are tested. The measurements document that under low freestream turbulence conditions, pronounced differences exist in the flowfield between L/D = 7.0 and 2.3. The differences between L/D cases are less prominent at high freestream turbulence intensities. Generally, short-L/D injection results in `jetting' of the coolant farther into the freestream flow and enhanced mixing. Other changes in the flowfield attributable to a rise in freestream turbulence intensity to engine-representative conditions are documented.
|American Society of Mechanical Engineers (Paper)
|Published - Dec 1 1996
|Proceedings of the 1996 ASME International Mechanical Engineering Congress & Exhibition - Atlanta, GA, USA
Duration: Nov 17 1996 → Nov 22 1996