Presented at the International Gas Turbine and Aeroengine Congress and Exposition, Houston, Texas - June 5-8, 1995.

Presented at the International Gas Turbine and Aeroengine Congress and Exposition, Houston, Texas - June 5-8, 1995.

Laser velocimetry was utilized to map the velocity field in a serpentine turbine blade cooling passage at Reynolds and Rotation numbers of up to 25.000 and 0.48. These results were used to assess the combined influence of passage curvature and Coriolis force on the secondary velocity field generated. A Navier-Stokes code (NASTAR) was validated against incompressible test data and then used to simulate the effect of buoyancy. The measurements show a net convection from the low pressure surface to high pressure surface. The interaction of the secondary flows induced by the turns and rotation produces swirl at the turns, which persisted beyond 2 hydraulic diameters downstream of the turns. The incompressible flow field predictions agree well with the measured velocities. With radially outward flow, the buoyancy force causes a further increase in velocity on the high pressure surface and a reduction on the low pressure surface. The results were analyzed in relation to the heat transfer measurements of Wagner et al. (1991). Predicted heat transfer is enhanced on the high pressure surfaces and in turns. The incompressible flow simulation underpredicts heat transfer in these locations. Improvements observed in compressible flow simulation indicate that the buoyancy force may be important. Tse, D. G. N. and Kreskovsky, J. P. and Shamroth, S. J. and Mcgrath, D. B. Unspecified Center BUOYANCY; CHANNEL FLOW; CONVECTIVE HEAT TRANSFER; COOLING; FLOW DISTRIBUTION; FLOW VELOCITY; TURBINE BLADES; COMPRESSIBLE FLOW; CORIOLIS EFFECT; INCOMPRESSIBLE FLOW; LASER DOPPLER VELOCIMETERS; NAVIER-STOKES EQUATION; REYNOLDS NUMBER; SECONDARY FLOW; VELOCITY DISTRIBUTION...