Computation of Heat Transfer In Turbine Rotor Blade Cooling Channels with Angled Rib Turbulators

Abstract

The effects of rotation and Reynolds number on heat transfer in rotating two-pass square and rectangular channels with smooth walls and walls with 45 degree angled and V-shaped rib turbulators were investigated numerically using an unstructured, incompressible, Reynolds-averaged Navier-Stokes flow solver. The influence of 45 degree angled ribs and channel orientation on the local Nusselt number ratios for leading and trailing surfaces in a two-pass square channel (AR=1) are compared to experimental data for Reynolds numbers from 5,000 to 25,000 and dimensionless rotation numbers from 0.0 to 0.118. The influence of V-shaped ribs and channel orientation on the local Nusselt number ratios for leading and trailing surfaces in a two-pass rectangular channel (AR=2) are compared to experimental data for Reynolds numbers from 5,000 to 40,000 and rotation numbers from 0.0 to 0.210. It is concluded that rotation causes significant changes to the local Nusselt number ratio distribution relative to stationary conditions. Generally, the first pass trailing and second pass leading surfaces have increased local Nusselt number ratios due to the secondary ow impingement induced by rotation. Alternatively, the first pass leading and second pass trailing surface Nusselt number ratios tend to decrease with increased rotation.