A Swirl Cooling Flow Experimental Investigation on a Circular Chamber Using Three-Dimensional Stereo-Particle Imaging Velocimetry

Abstract

Abstract An experimental investigation is presented using three-dimensional (3-D) stereo-particle image velocimetry (stereo-PIV) of a swirl flow that models a gas turbine blade internal cooling configuration. The study is intended to provide an evaluation of the developments of the swirl cooling flow methodology utilizing the 3-D stereo-PIV. The objective is to determine the critical swirl number that has the potential to deliver the maximum axial velocity results. The swirl cooling flow methodology comprises cooling air channeling through the blade’s internal passages lowering the temperature; therefore, the experimental circular chamber is made of acrylic allowing detailed measurements and includes seven discrete tangential jets designed to create the swirl flow. An oil particle seeder (LAVision) is used to provide the particles for velocity measurements while the clear acrylic chamber allows visualization of the flow phenomena. The post-processed data are completed using davis, velocity calculations are conducted in matlab, and techplot is used for data visualization. The focus of this investigation is on the continuous swirl flow that must be sustained via continuous injection of tangential flow at three different Reynolds number, 7000, 14,000, and 21,000, where the swirl flow is generated with seven inlets. Important variations in the swirl number are present near the air inlets and decreases with downstream distance as predicted, since the second half of the chamber has no more inlets. The axial velocity reaches the maximum downstream in the second half of the chamber. The circumferential velocity decreases the downstream distance and reaches the highest toward the center of the chamber.