Rotational Effects on Heat Transfer at Advanced Engine Conditions Free

Cooling of Gas turbine buckets to ensure adequate life margin with coolants at advanced engine conditions of pressure and temperature requires that the internal heat transfer as influenced by rotation be known with sufficient accuracy. The existing data base, comprised of information readily available in the open literature has limited advanced design applicability considering the range of geometric and fluid-thermal dimensionless parameters of interest. Further, studies conducted with the aid of computational fluid dynamics (CFD) have demonstrated that, as the range of such parameters is extended, the characteristics of the predicted heat transfer capability change significantly, to the extent that bucket coolant passage designs that are fully acceptable at state-of-the-art conditions are marginal or unacceptable at advanced conditions. The purpose of this paper is threefold, to: a) demonstrate the need for extending the current internal heat transfer data base, accounting for the effects of rotation, b) provide a physical understanding of the expected heat transfer characteristics at advanced conditions, and c) describe a test rig and test program focused on obtaining the data of interest.