Flow and heat transfer characters in the integral internal cooling channel of a turbine blade

Abstract

A scaled model of the integral internal cooling channel of a turbine blade was established for the experimental investigation. The model was made by Perspex for its transparency so that the thermochromic liquid crystal measurement could be used easily. The cooling channel is composed of 3 legs of ribbed channels. Rib with angle 45° was settled in both pressure side and suction side, which forms a cross-rib structure. Three legs were connected by two 180° turns. The main inlet and two addition inlets were arranged in the root of the model channel. Two discharge outlets were located in the tip. A row of outlet holes was distributed along the trailing edge. The channel area gradually decreases along the blade height direction, while bending and torsion occur because of the blade airfoil shape. The aspect shapes and connection methods of the channel were kept in accordance with the real blade. The inlet Reynolds number is from 10000 to 32000. Five outlet discharge ratios were alternated in this investigation. The detailed heat transfer distributions, both in the pressure side and suction side, were measured by transient liquid crystal technic. The characters of heat transfer distribution and pressure drop along the channel were displayed. The effects of flow discharge ratio on heat transfer and pressure coefficient were also described.