Combined heat transfer and flow field analysis in rib-roughened cooling passages for turbine blades

The present study deals with a detailed experimental investigation of the turbulent flow inside a rib-roughened turbine blade cooling channel. The measurements are carried out by means of a 2D PIV technique in a stationary straight channel with 10% blockage ribs installed on one wall. They constitute the necessary complement to the already available heat transfer data. The present aerodynamic results are compared with available data on a similar channel but with a blockage ratio of 30 %. The main objective is to deepen the analysis and enhance the understanding of this complex flow field, particularly with respect to the definition of a mean flow model and to its aero-thermal characteristics. More precisely, the stream-wise/normal to the wall component of the Reynolds stress tensor is shown to be closely related to the heat transfer rate on the channel surfaces. A correlation to estimate the heat transfer field from the aerodynamic data, previously obtained for the high blockage rib roughened channel flow, is validated for this 10% blockage configuration.