Sustainable Thermal Solutions: Enhancing Heat Transfer with Turbulators and Nanofluids

Actual performance of heat transfer devices significantly influences the general efficiency of the energy conversion systems. Among all active and passive techniques of heat transfer enhancement, the current review has been focused on turbulators and their integration with nanofluids due to cost-effectiveness and practicality. The turbulators like coiled tubes, extended fins, and swirl flow devices create local vortices to distort the fluid flow boundary layer, which results in an enhanced convective heat transfer process. Further, the use of nanofluids with improved thermophysical properties can also be considered to see the synergizing effect of turbulators for further enhancements in the heat transfer rates. The present review reflects that, among the different turbulators considered, the wire coil insertion offers better thermal efficiency with reduced pressure drops. Thus, the combined approach using nanofluids and turbulators has ample potential to attain higher heat transfer performance compared to conventional methods. Despite the great development, the full mechanism, especially with nanofluid interactions, is still not well elucidated. Current limitations and future research opportunities are highlighted in this review to emphasize that continuous studies are needed to optimize these techniques in order to have better energy systems.