Investigation of the Conjugate Convective-Conductive Thermal Behavior of a Rib-Roughened Internal Cooling Channel

The proposed contribution concerns an experimental investigation of the conjugate thermal behavior of a rib-roughened cooling channel. Previous investigations mainly were focused on the convective aspects of the heat transfer; the scaled models were made of low conductivity material and the heat conduction was not representative of the behavior inside a real metallic airfoil. To overcome this limitation, a large-scale facility with a metallic ribbed wall was designed and tested. Infrared thermography was used to measure the temperature distribution on the wetted surface. Dedicated software was developed to correct the temperature field distortions and to apply the radiation-temperature calibration. The convection coefficient was calculated as a function of the measured wall temperature and computed wall heat flux. The code FLUENT^® was used to solve the energy equation into the metallic wall, providing the surface heat flux distribution. The complex contribution of the ribs, in terms of heat transfer, was highlighted.