Studies on influence of nozzle parameters and swirl on heat transfer in multi jet impingement cooling

Abstract

Jet impingement cooling finds application in many engineering newlineindustries due to its ability to produce high local heat transfer coefficients. newlineAnnealing of metal and plastic sheets, tempering of glass sheets, drying of newlinepaper and textiles, cooling of gas turbine blades, electronic components, newlinechemical vapour deposition and anti-icing of aircrafts are some of the newlineimportant applications. Detailed investigations on the characteristics of single newlinejet and the ways of improving its performance have been carried out by many newlineresearchers. As the area of influence of a single jet is limited to only a few newlinetimes its diameter, for cooling a larger area, multi-jet configuration is to be newlineused. Even though the multi-jet impingement cooling has been one of the newlineactive areas of research for the past twenty years, a comprehensive procedure newlineto design the system and to arrive at the optimum conditions are yet to be newlineestablished.This research work aims to study the effects of jet diameter, jet to newlinetarget space distance, swirl, cross section of the jet, number of jets and their newlinearrangement on heat transfer coefficient in multi-jet air impingement cooling. newlineAn electrically heated steel plate of size 150 mm x 100 mm has been used for newlinestudying the dissipation of a set value of heat flux of 7666.67 W/m2. An air newlineblower with necessary flow control and a plenum chamber is used for newlinesupplying the air to the jets. A hot wire anemometer was used to measure the newlinevelocity of air flow and K-type thermocouples (15 Pieces) for measuring the newlinetemperatures of the hot plate at different locations. A data logger and a PC newlinehave been used for recording the measured data. newline newline