Nanofluid flow and heat transfer from heated square cylinder in the presence of upstream rectangular cylinder under Couette-Poiseuille flow

摘要

A heated square cylinder (with height A*) is kept parallel to the cold wall at a fixed gap height 0.5A* from the wall. Another adiabatic rectangular cylinder (of same height A* and width 0.5A*) is placed upstream in an inline tandem arrangement. The spacing between the two cylinders is fixed at 3.0A*. The inlet flow is taken as Couette-Poiseuille flow based non-linear velocity profile. The conventional fluid (also known as base fluid) is chosen as water (W) whereas the nanoparticle material is selected as Al2O3. Numerical simulations are performed by using SIMPLE algorithm based Finite Volume approach with staggered grid arrangement. The dependencies of hydrodynamic and heat transfer characteristics of the cylinder on non-dimensional parameters governing the nanofluids and the fluid flow are explored here. A critical discussion is made on the mechanism of improvement/redaction (dale to the presence of the upstream cylinder) of heat transfer and drag coefficient, in comparison to those of an isolated cylinder. It is observed that the heat transfer increases with the increase in the non-linearity in the incident velocity profile at the inlet. For the present range studied, particle concentration has a negligible effect on heat transfer.