Detailed Heat Transfer Measurements of Jet Impingement on Dimpled Target Surface Under Rotation

Abstract

The present study investigates the effects of Coriolis force and centrifugal buoyancy force on heat transfer due to jet impingement on dimpled target surface (DT). Detailed heat transfer measurements were carried out using transient liquid crystal (LC) thermography, where the target surface was modeled as one-dimensional (1D) semi-infinite solid. Three different configurations of DT surfaces have been studied. The flow and rotation conditions have been kept the same for all the configurations, where the average Reynolds number (based on jet hole hydraulic diameter: Rej) was 2500 and the rotational speed was 400 rpm (corresponding to Roj of 0.00274). Under nonrotating conditions, DT surface showed positive heat transfer enhancements compared to smooth target surfaces. Under rotating conditions, it was observed that rotation was helpful in enhancing heat transfer on leading and trailing sides for smooth target surface. However, for the DT surfaces, rotation proved to be detrimental to heat transfer enhancement.