Simultaneous Prediction of External Flow-Field and Temperature in Internally Cooled 3-D Turbine Blade Material

Abstract

A two-dimensional (2-D) and a three-dimensional (3-D) conjugate heat transfer (convection-conduction) prediction codes were developed where the compressible turbulent flow Navier-Stokes equations are solved simultaneously in the flow-field and in the solid material of the structure thus automatically predicting correct magnitudes and distribution of surface temperatures and heat fluxes. The only thermal boundary conditions are the convection heat transfer coefficients specified on the surfaces of the internal coolant flow passages and the coolant bulk temperature of internally cooled gas turbine blade. This approach eliminates the need to specify hot surface temperature or heat flux distribution. The conjugate codes use hybrid unstructured triangular/quadrilateral grids in 2-D and unstructured prismatic grids in 3-D throughout the flow-field and in the surrounding structure. The codes are capable of conjugate heat transfer prediction in arbitrarily shaped internally cooled configurations. The computer codes have been successfully tested on internally cooled turbine airfoil cascades and 3-D turbine blades by the conjugate solution of the flow-field and the temperature field inside the structure.