Numerical study of implemented eco-friendly nanofluid in the pinfin-equipped heatsinks with novel C-shaped and V-shaped patterns

C-shaped and V-shaped patterned pinfins over the heated surface in a microchannel geometry are investigated for the laminar flow regime. The working fluid in the simulations is water mixed with graphene nanoplatelet nanoparticles where three different concentrations of particles are considered. The effect of the inertia of the fluid is considered at three distinct values of specified inlet velocities. Three cross-sections including circular, square, and triangular cross-sections have been utilized to show individual pinfin effects on the flow field as well as the temperature distribution. User-defined function routine is developed for the fluid viscosity and thermal conductivity as a means of performing the nanoparticle concentration effect. The thermal resistance, temperature uniformity index, and average temperature all decrease with increasing inlet velocity and concentration. An increase in the convective heat transfer coefficient enhances the temperature distribution index and hence the uniformity. Higher growth of heat transfer coefficient over the pressure drop is obtained for the cases with nanofluid inclusion in comparison with pure water. Accordingly, greater than unity values for the figure of merit is reached. The triangular cross-sectioned pinfin with the C-shaped pattern reached better results in temperature uniformity index, convective heat transfer coefficient, and thermal resistance. For the triangular cross section, the value of thermal resistance decreased by 4.4 % for the C-shaped pattern in comparison with the V-shaped one at the highest defined concentration and the inlet velocity of 0.15 ms⁻¹. The figure of merit and pumping power reached the highest values for the square cross section with the C-shaped pattern.