Experimental and numerical study of heat transfer and friction factor characteristics of an inclined elliptical dimple channel having inline and staggered pattern

Experimental and numerical studies were carried out to examine the effect of staggered and inline inclined elliptical dimpled plate on Nusselt number (Nu) and friction factor (f) for higher Reynolds number (Re) values. Dimple dimensions of different elliptical dimple pattern were kept constant to compare their thermal performance effectively with the dimple depth (d(e)) and dimple diameter (d(p)) kept as 3 mm and 10 mm respectively for the present study. The features, namely Nu, f and flow structure of the inclined elliptical dimpled plate were calculated for 'Re' values ranging from 11,300 to 62,000. The experiment showed that inclined elliptical dimple with staggered and inline arrangement has different effect on flow pattern and heat transfer characteristics. The staggered pattern has 24.8% greater heat transfer and 10.71% lower pressure drop corresponding to inline pattern. The three-dimensional numerical computations clearly show that different test plates have different vortex flow structures and these vortex flow patterns of dimpled plate result in improved heat transfer in comparison to flat plate.