The effect of step height of microscale backward-facing step on mixed convection nanofluid flow and heat transfer characteristics

Simulation of laminar mixed convective flow over a 3-D horizontal microscale backward-Facing step (MBFS) is presented to explore the effect of step height on the flow and heat transfer characteristics. The momentum and energy equations were discretized by means of a finite volume method (FVM). The SIMPLE algorithm scheme was used to link the pressure and velocity fields in the entire domain. Three values of step height were considered S = 350 μm, S = 450 μm and S = 550 μm. EG-SiO2 nanofluid was considered as the working fluid with 25 nm nanoparticle diameter, 0.04 volume fraction. The results revealed that the Nusselt number and skin friction coefficient increase with the increase of the step height. The Reynolds number and pressure drop were found to decrease with the increase of the step height.