Investigating the thermal dynamics of two-layered immiscible fluids in corrugated curved channel with applied heat source

Abstract

The corrugated curved channels (CCs) in heat exchangers can enhance the heat transfer where two immiscible fluids are used, by promoting interfacial areas. The results of this study may inspire creative designs for thermal management systems, which could result in the creation of new applications and technology. The corrugations improve the energy collection and conversion efficiency. In solar thermal collectors, a heat source in corrugated curved channels is used to improve solar energy absorption to transfer it to a working fluid. On the other hand, the heat sinks are used to remove the heat that is not needed during the chemical separation processes. With this motivation, the main aim of this study is to analyze the heat transfer enhancement in two-layered immiscible viscous fluids (VFs) flow by using the heat source/sink phenomenon. The curved channel is divided into two regions. Both regions are occupied with VFs having different viscosities. The flow is caused by a constant pressure gradient. The analytical expressions for velocity and temperature are obtained through the perturbation series method (in terms of small corrugation amplitude $\epsilon \ll 1$) by solving the mathematical model of partial differential equations. The effect of different parameters on fluid and heat flow is analyzed through graphs and contours. Moreover, the shear stresses (SS) at the walls of CC with corrugated boundaries, rate of heat transport and volume flow rate (VFR) are also analyzed and discussed. The results show that the heat is more enhanced when a heat source is provided to the system whereas a heat sink causes a fall in heat through the immiscible VFs flow. So, to enhance the heat when necessary, a heat source can be used in corrugated CC. Furthermore, SS is decreased when the wavenumber is increased. The wavenumber implies a small corrugation wavelength which leads to a more undulating path. For this type of path, a larger amount of SS is needed for fluid to flow at walls.