Optimizing thermal performance in shell-and-tube heat exchangers with tri-hybridised nanofluids: a numerical study of turbulent convection

This investigation explores heat transfer enhancement in shell and tube heat exchangers using a tri-hybrid nanofluid suspension consisting of copper (Cu), iron oxide (Fe₃O₄), and multiwall carbon nanotubes (MWCNT) dispersed in water as the base fluid. The numerical simulation employs a novel Galerkin finite element method (GFEM) to study turbulent convection influenced by Reynolds number, tube radius, and nanoparticle volume fraction. The complex interactions among these physical parameters are analyzed in terms of average Nusselt number, entropy generation, and flow behavior. Results demonstrate that increasing nanoparticle concentration and fluid velocity significantly improve heat exchanger efficiency. Visualization tools such as streamlines, entropy contours, and isotherms provide comprehensive insight into optimizing thermal management systems.