Experimental Investigation of Heat Transfer Enhancement on Impinging Jet Cooling Using Surface Laser Treatment

Present paper gives detailed report about the unsteady heat transfer characteristics of bottom jet impingement on hot stainless steel plate. In particularly, the rewetting phenomena of 0.25 mm thickness of horizontally bottom faced stainless steel thin plate are studied by experimentally. Plate initial temperature is 300 °C taken for all the cases. FLIR system (A655sc) is used to predict the unsteady heat transfer characteristics SS sheet under bottom jet impingement. Reynolds number (Re) of bottom impinging jet ranges varied from 5000 to 10,000. The distance between jet and plate (z/d) is 10, and the nozzle diameter is 1 mm for all the cases. The thermal camera (FLIR) is used to capture the transient temperature variation on SS sheet. From the obtained results, the parameters effect on unsteady heat transfer has been obtained. The effect of laser power also is studied by varying power input on laser treatment. Laser power 35 W, laser speed s = 30 bits/ms are taken for present investigation. From the obtained results, it is concluded that the heat transfer is enhanced on jet impingement when laser treatment plate used.