Rotating heat transfer investigations on a multi-pass cooling geometry

The effect of rotation on the heat transfer in a complex 3D multi-pass turbine blade cooling geometry is reviewed. The test rig, the experimental technique and the initial results are discussed in detail. Basic checks at zero rotational speed showed good agreement with data obtained earlier on this model using an alternative transient technique. Rotation was shown to have a significant effect on the heat transfer distribution (+ or - 30%) which when averaged over the gas washed surfaces showed a reduction to 90% of the static value. The effect of these changes on the blade predicted metal temperatures and lives are also reviewed. Investigations are continuing to fully evaluate the implications of both Coriolis and buoyancy effects on the heat transfer distributions in these complex 3D geometries.