Temperature field measurements of thermal boundary layer and wake of moving hot spheres using interferometry

摘要

Highlights?Interferometry is used to obtain temperature fields of flow around a hot sphere.?Detailed methodology on the post-processing is presented.?The experimental temperature field is compared against a numerical one.?Excellent quantitative agreement is found in the vicinity of the sphere.AbstractThe methodology used to post-process a raw interferogram of a hot moving sphere falling in an inert nitrogen environment is presented. The steps taken to obtain the temperature field around the hot sphere are explained in detail. These are: (1) noise removal; (2) phase demodulation; (3) phase unwrapping; (4) bias removal; and (5) Abel transform inversion. All the typical features of the flow are revealed such as growth of the thermal boundary layer, shallower temperature gradients were the flow separates, and a hot wake in the recirculation zone. For validation of the methodology, the temperature field is compared again