Fluid–Structure Interaction With Mixed Convection in a Vented Trapezoidal Cavity Filled With Power‐Law Fluid

ABSTRACT Active cooling is resorted to enhance the heat removal from hot bodies when the ambient temperature is relatively high. The current problem benefits the fluid–structure interaction by introducing a flexible fin to modulate the non‐Newtonian coolant entering into a trapezoidal vented cavity, and investigates the roles of various Prandtl numbers (Pr = 2–10) and different fin specifications (based on inlet width H) such as its thickness ( ξ = 0.1–0.2), elasticity ( E = 10 4 –10 15 ), and proximity ( L = 1–2) to the coolant inlet. The numerical solution of the problem is conducted by FEM and supported by two numerical verifications. Power law model is adopted for the non‐Newtonian fluid ( n = 0.5, 1, 1.5) and laminar flow regime (Re = 100–500). The results show that the use of flexible fin modulates and guides the flow and promotes the average Nusselt number better than it was not used. The gain in Nu av number is about 17.6% for pseudoplastic fluid and 20.7% for Newtonian fluid, while for the dilatant fluid, the flexible fin is less beneficial. For better heat transfer, we propose a fin thickness of 0.1H and a fin location as close as 1H to the inlet port, where H is the width of the inlet and outlet ports. Also, the dimensionless elasticity property of the fin should be as low as 10 4 to obtain better convective heat transfer.