Heat transfer over rotor surface in a pre-swirl rotating-disc system

Pre-swirl is often used in the internal cooling-air systems of gas turbines to reduce the temperature of the cooling air relative to the rotating turbine blades. In a "direct-transfer" system, the air passes axially across the wheel-space from stationary pre-swirl nozzles to receiver holes in the rotating turbine disc. This paper investigates heat transfer over rotating disc of such a system, using a 3D steady, incompressible turbulent flow in rotating frame of reference. Computed results are compared with measurements of static and total pressure coefficients and heat transfer coefficients obtained by [4]. There is mainly good agreement between computed and measured values of pressure coefficients. There are less agreement between measured and computed local hest transfer coefficients. The computed as well as measured local hest transfer coefficients shows axisymmetric distribution on rotor except near receiver cooling holes in which a small region of high heat transfer is observable.