Flow structure measurement in a trapezoid duct with incline impingement jets near the leading edge

The internal cooling cavities always had complicated geometry near the leading edge. A simplified trapezoidal duct was built up for experimental research. The primary objective was to visualize the flow structure and flow characteristics in the duct with combined complicated flow conditions. It would provide useful information for the design of highly effective internal cooling system. Experimental measurements were performed using a seven-hole probe. The effect of impingement, cross flow and outflow were considered. Important results of the research include: Impingement jets at high position impinged the target wall effectively, while those at low position contributed to inducing and impelling swirl flow, and the latter were accessible to cross flow influence. The counter-clockwise swirl flow was enhanced with the increasing power of cross flow, but the impingement was deteriorated. At higher impingement angle, the impact effect of the jets was enhanced but swirling strength of the vortex was decreased. The changes of mass flow rate and outflow position of film cooling holes had no distinct effect on the main flow structure in the passage.