CHARACTERIZATION OF THE VELOCITY AND HEAT TRANSFER FIELDS IN AN INTERNAL COOLING CHANNEL WITH HIGH BLOCKAGE RATIO

摘要

The present experimental study is dealing with a detailed aero/thermal investigation of the turbulent flow inside a rib-roughened turbine blade cooling channel by means of Particle Image Velocimetry (PIV) and Liquid Crystal Thermometry (LCT). The main objectives of the paper are to provide detailed information about the behaviour of such a complicated flow, useful for its understanding, and to create a wide and reliable data base for numerical code validation. The measurements are carried out at engine representative Reynolds number within a scaled up model of a stationary straight cooling channel, with turbulent promoters (or ribs) installed on one wall. The ribs have an angle of attack of 90 deg with respect to the "mean" flow direction; their blockage ratio is equal to 30%. Detailed wall heat transfer distributions are presented. The main time-averaged flow features are identified and quantified; a number of rms characteristics are put in evidence and compared to the heat transfer distributions.