numerical study of the effect of creating a triangular step on increasing the forced heat transfer coefficient in the tube containing nanofluid fe3o4 under the solar panel

In this two-dimensional numerical paper, the effect of increasing the heat transfer coefficient of forced displacement of fe3o4 nanofluid in a triangular perforated tube with a triangular perforated panel, under a constant heat flux placed around the tube, compared to a circular direct tube, fluid flow which is selected slowly by moving in the pipe and colliding with the pipe steps, the thermal boundary layer is disturbed and this has increased the heat transfer coefficient of fluid flow displacement. the results show that the creation of stairs inside the pipe increases turbulence with the fluid flow is transverse along the surface, which eventually results in a smoother temperature profile and a flatter temperature profile and a reduction in the thickness of the thermal boundary layer, which leads to an increase in heat transfer coefficient. therefore, by increasing the volume of nanofluid by 4.5%, the transfer heat transfer coefficient is optimized by 9.4% in a triangular hollow tube with a solar panel compared to a simple tube.