FLOW AND HEAT TRANSFER OF NON-NEWTONIAN FLUIDS IN CONFINED TRIANGULAR GEOMETRIES: A COMPUTATIONAL APPROACH

This study examines mixed convection heat transfer in a lid-driven triangular cavity containing three heated horizontal finned cylinders immersed in power-law fluids. The cavity features inclined sidewalls maintained at a cold temperature, while the top adiabatic lid moves at a uniform velocity. The objective is to analyze the fluid’s behavior and its influence on flow structure, heat transfer, and drag coefficients under varying conditions, including lid speed, thermal buoyancy intensity, and fluid viscosity characterized by the power-law index. The study employs numerical simulations based on the finite volume method to solve the governing equations, with the fluid’s rheological behavior modeled using Ostwald’s law. Results show that the heat transfer rate increases with Re, Ri, and n, with the bottom cylinder (C3) exhibiting the highest rate due to strong buoyancy and focused recirculation zones. The drag coefficient (CD) decreases with Re but varies significantly with n, leading to higher drag forces for shear-thinning fluids. These findings provide new insights into optimizing heat transfer and drag in non-Newtonian fluid systems.