Three‐dimensional convective flow in a CNT‐Gallium nanoliquid‐filled cavity equipped with horizontal fins

Abstract The current study presents a detailed numerical investigation of buoyancy‐driven three‐dimensional heat transfer and fluid flow within a cubic cavity filled with Carbon nanotube (CNT)‐Gallium nanoliquid and equipped with horizontal fins. The finite volume method (FVM) is employed to solve the governing equations in an arrangement that includes a hot fin on the left wall and a cold fin on the opposite side while all other walls are adiabatic. This study examines the variation effects of fin lengths (0.1 to 0.4), Rayleigh numbers (10 3 to 10 5 ) and CNT nanoparticle concentrations (0 to 0.045) on convective heat transfer performance. Results demonstrate that fin length significantly affects fluid flow and heat exchange with the shortest fin ( W = 0.1) yielding the highest heat transfer rates. The maximum heat transfer enhancement is achieved at Ra = 10 5 and φ = 0.045 where the average Nusselt number increases by approximately 40% compared to the base fluid. Furthermore, increasing nanoparticle concentration enhances thermal conductivity and overall heat transfer while it also raises viscosity and consequently reduces the flow intensity. This investigation emphasizes the critical role of fin geometry and nanoparticle concentration in the thermal performance optimization for advanced heat exchange applications.