Numerical and Experimental Analysis of Heat Transfer for Various Shapes of Dimple Surfaces

The vital application in the domain of cooling is to increase the rate of heat being transferred from the object. The heat transfer coefficient between the surface and its surroundings can be increased by augmenting surface area. Diverse methods are employed to enhance the rate of cooling from any application like a plate. The technique used can be either active or passive technique. The present work uses one of the passive methods of transfer of heat using various shapes of dimples on the surface. In this paper, an innovative technique of creating dimple surfaces on the given plate is used for increasing surface area. In the experiment, circular, semi-circular, and elliptical-shaped dimples are used in a forced convection environment for carrying out numerical as well as experimental investigation. The numerical result shows that circular shape dimples have a greater heat transfer rate compared to both semi-circular and elliptical shape dimples. Further, numerical analysis is carried out for circular dimple shapes by varying different process parameters like dimple depth, diameter, and velocity. Taguchi method is used for optimization. Process parameters are decided for optimization, and the orthogonal array is obtained for these levels. Taguchi technique tests pairwise combinations of different process parameters used within their levels. It allows the least amount of experimentation to determine which factors have the greatest impact on product quality, saving time and resources. Further numerical and experimental analysis is carried out for the optimized path obtained through the Taguchi method. Total heat transfer rates for numerical and experimental work match and thus is validated. The total heat transfer rate for numerical work is found to be 19.1054 W and for experimental work is 19.0068 W. In this research work, the k-ε model is used for computational analysis using ANSYS 18 software.