Detailed heat/mass transfer measurements on stationary blade with various relative positions

The present study investigated the effect of relative position of the blade on turbine blade and shroud heat transfer. The experiments were conducted in a low speed wind tunnel with stationary annular turbine cascade and the test section has a single turbine stage. The chord length of the blade is 150 mm and the mean tip clearance of the blade is about 2.5% of the blade chord. The Reynolds number based on blade inlet velocity and chord length is 1.5×10 ⁵ and mean turbulence intensity is about 3%. To investigate the effect of relative position of blade, the detailed heat/mass transfer measurements were performed for the stationary blade at four different positions in a single pitch. A naphthalene sublimation technique was used to obtain detailed heat/mass transfer coefficients on the blade and shroud. The results show that the blade relative position changes the distributions of velocity magnitude and turbulence intensity and consequently affects heat transfer characteristics. Especially, the heat transfer pattern near the tip on the suction side surface varies significantly because the behavior of tip leakage flow changes.