P. Chandramohan - Misrimal Navajee Munoth Jain Engineering College, Chennai, Tamilnadu, India
S. N. Murugesan - Rajalakshmi Engineering College, Chennai, Tamilnadu, India
S. Arivazhagan - St. Joseph’s College of Engineering, Chennai, Tamilnadu, India

This experimental analysis encapsulates the influence of Reynolds number (Re), diameter of nozzle, height to diameter (H/D) ratio and position of nozzle such as in-line and staggered over the responses heat transfer coefficient, temperature and Nusselt number of a hot flat plate exposed to cooling by multi-jet air impingement. For this analysis, a ۱۵ x ۱۰ cm flat plate is being heated using a heating coil having a heat flux of ۷۶۶۶.۶۷ W/m۲ which is maintained as constant through entire experiment. An H/D ratio of ۲D, ۴D and ۶D is considered along with pipe diameters of ۴, ۶ and ۸ mm and Reynolds number are changed between ۱۸۰۰۰ to ۲۲۰۰۰. Experimental design was performed with response surface methodology based central composite design. For all output responses, a quadratic model is chosen for analysis and a second order mathematical model is evolved for predicting with a higher R۲ value. Desirability analysis is performed for multi-objective optimization and the optimum input parameters obtained are Reynolds no. of ۲۰۳۴۷, pipe diameter of ۸ mm, H/D ratio of ۲ and in-line nozzle position with the maximum heat transfer coefficient of ۱۸۹.۴۱۱ W/m۲ K, Nusselt number of ۲۸.۸۷۱۲ and minimum temperature of ۵۶.۹۸۳°C. Optimum condition-based confirmation experiments result in enhanced Nusselt number and heat transfer coefficient.

Jet impingement cooling, Staggered and inline position, Heat transfer, Response surface methodology, Nusselt number, Reynolds number