Experimental and numerical investigations of fluid flow and heat transfer in a bioinspired surface enriched microchannel

In this paper, experimental and numerical studies of fluid flow and heat transfer characteristics of novel fish scale bioinspired structures on the bottom surface of microchannel to enhance heat transfer are presented. Deionized water is selected as the working fluid. A three-dimensional numerical model is developed to analyse conjugate heat transfer in the microchannel, and the model is validated with the experimental results obtained from a copper microchannel of hydraulic diameter of 193.5 μm and length of 20 mm for three different Reynolds numbers and a constant bottom heat flux of 50 W/cm2. Further the numerical model is extended to study the effect of several geometrical parameters on the thermohydraulic performance of microchannel. It is found that the bioinspired surface can enhance the convective heat transfer compared to the plain microchannel, whereas the pressure drop is found less for fish scale structure with dimensionless inclination height of 0.026. The friction factor for the fish scale inclination height of 0.026 reduces by maximum 5% and the Nusselt number increases by maximum 14% as compared to those quantities for the plain microchannel. Further increment in the inclination height increases the heat transfer rate and friction factor than the plain microchannel. The maximum value of the performance evaluation criteria is found as 1.75 at inclination height of 0.26 and Re = 1050. Correlations of Nusselt number and Poiseullie number are developed for this type of microchannel.