An experimental investigation to analyse the heat transfer characteristics of hot surface by obliquely impinging liquid jet

Abstract

In the present study, an experimental investigation has been carried out to analyze the effect of jet inclination on the heat transfer characteristics of a vertical hot surface during circular free impinging liquid jet. A rectangular stainless steel foil (AISI-304, 0.15 mm thick), used as the target surface, was electrically heated to an initial temperature of 400 °C. A single-phase circular water jet of diameter 1.38 mm is allowed to impinge on the hot surface. Infrared thermal camera (A655sc, FLIR System) is used to record the thermal images of the target surface during liquid jet impingement. The distribution of heat flux on the target surface is evaluated from the thermal images, recorded during transient cooling experiments. Tests were performed for an initial surface temperature of 400 °C, Reynolds number (8893 ≤ Re ≤ 12847), and nozzle to plate distance (2.5 ≤ l/d ≤ 4.5) and jet inclination (0 ≤ α ≤ 45°). The heat flux is found to be maximum at stagnation point for the jet inclination of 30°. It is observed that the jet to plate spacing has minimal effect of stagnation point maximum heat flux.