The document reviews advancements in computational fluid dynamics (CFD) analysis of shell and tube heat exchangers utilizing nanofluids and twisted tape turbulators to enhance heat transfer efficiency. It highlights the potential of nanofluids to improve thermal conductivity and the role of twisted tape in altering flow dynamics, while addressing challenges like nanoparticle agglomeration and increased pressure drop. The findings illustrate the synergy of these technologies, presenting insights for optimizing heat exchanger designs in various industrial applications.