Experimental Investigation of Multi-Jet Air Impingement in Various Conditions and Analysis using Desirability Based Response Surface Methodology


1 Misrimal Navajee Munoth Jain Engineering College, Chennai, Tamilnadu, India

2 Rajalakshmi Engineering College, Chennai, Tamilnadu, India

3 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 15 x 10 cm flat plate is being heated using a heating coil having a heat flux of 7666.67 W/m2 which is maintained as constant through entire experiment. An H/D ratio of 2D, 4D and 6D is considered along with pipe diameters of 4, 6 and 8 mm and Reynolds number are changed between 18000 to 22000. 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 R2 value. Desirability analysis is performed for multi-objective optimization and the optimum input parameters obtained are Reynolds no. of 20347, pipe diameter of 8 mm, H/D ratio of 2 and in-line nozzle position with the maximum heat transfer coefficient of 189.411 W/m2 K, Nusselt number of 28.8712 and minimum temperature of 56.983°C. Optimum condition-based confirmation experiments result in enhanced Nusselt number and heat transfer coefficient.