Pulsating nanofluid flow in a wavy bifurcating channel under partially active uniform magnetic field effects

Abstract

Separated flow and thermal performance characteristics by combined utilization of surface corrugation, partially active magnetic field, nanoparticle loading in the base fluid and flow pulsations are analyzed numerically in a bifurcating channel by using finite element method. Size and number of vortices are affected by the variation corrugation height and wave numbers while the vortices are damped by using partially active magnetic field in different domains. When various methods are compared, by using corrugations highest heat transfer improvement is achieved followed by the flow pulsations and magnetic field. By utilization of nanofluids, thermal performance is further improved. When corrugation height is considered, enhancement up to 248.3% is obtained for wave number of 8 while variation in the average Nusselt number (Nu) becomes only 22.9% with varying wave number. The enhancement amount with pulsating flow amplitude depends upon the nanoparticle loading amount in the base fluid. At solid volume fraction of 0.02%, the average Nu increases by about 79.8% with pulsating flow at the highest amplitude as compared to steady flow case. Dynamic models with system identification are constructed for predictions of time dependent Nu variations for different pulsating amplitudes in the absence and presence of magnetic field for the bifurcating channel. The potential improvement of convective heat transfer in bifurcation channels is explored by combining different novel enhancement methods together. The results of the present analysis will be beneficial for performance improvement and optimization studies of bifurcating channel applications appeared in microelectromechanical systems, fuel cells and thermal management of diverse thermal systems.