Experimental Visualization of the Flow Structure for Jet in Crossflow with a Curved Hole Passage

Abstract

The objective of this paper is to investigate the influence of a hole curvature on the flow structure and characteristics downstream of JICF (jet in cross-Flow) by means of smoke visualization and particle image velocimetry (PIV). The experiment was performed in a low speed wind tunnel with Reynolds numbers of about 480 and 1000, based on the hole diameter and main flow speed. Two geometries were tested: a circular hole with 90° curvature and a circular straight hole for comparison, under blowing ratios 0.5 and 1.0. The measurements were done in the symmetric plane and four cross-sections. The results show that the curved hole could decrease the mixing behavior of jet flow with the main flow as the hole leading edge also increases the chance of transportingthecoolant to the wall surface and the transverse coverage. The curved hole shows a high potential to increase the cooling effectiveness once it is applied to the turbine blades.