Experiment of heat transfer in internal cooling channel with tip and trailing edge outflows

Detailed local heat transfer distribution and average heat transfer trend at different inlet Reynold numbers with four discharge ratios were acquired by utilizing transient liquid crystal measurement. The purpose of this experimental study is to understand the effect on the heat transfer characteristic of a high pressure turbine blade internal cooling channel with different tip and trailing edge discharge ratios. The results show that: local heat transfer distributions are similar under different inlet Reynold numbers and the same discharge ratio; the discharge ratio has critical impact on local heat transfer distribution, especially in the second and third channels, where local and average heat transfer of these two channels have been weakened by outflow of the first tip hole. Different discharge ratios between the second tip holes and trailing edge have no obvious impact on local and average heat transfer of the first and second channels, but have critical impact on the third channel, while local and average heat transfer of this channel will be enhanced tremendously when the discharge ratio of trailing edge is raised.