Local mass (heat) transfer distribution over the concave surface of a turbine blade

This paper presents mass transfer results over the concave surface of a turbine blade using a naphthalene sublimation technique. An automated data acquisition system was employed to investigate the local mass transfer coefficient over a simulated turbine blade in a planar cascade. Results show a large variation along the spanwise direction in the local mass transfer distribution even in the two-dimensional flow region, possibly due to the effect of Taylor vortices. The average mass transfer distribution over the measured span has a sharp decrease in the leading edge region and a rapid increase during both the reattachment of the boundary layer flow and the trailing edge. A comparison with an earlier study using a direct heat transfer method is made and shows good agreement in the general trend of the heat transfer distribution.