Numerical investigation of turbulent CuO–water nanofluid inside heat exchanger enhanced with double V-cut twisted tapes

This numerical investigation aims to study the turbulent characteristics and thermal enhancement parameter of CuO–water nanofluids through heat exchangers enhanced with double V-cut twisted tapes. The twist ratio of the twisted tapes is 5.25, and the cut ratio ( b / c ) is varied from 0 (conventional twisted tape) to 1.8. The Reynolds number is in the range of 5000–15,000, and nanoparticles volume fraction is in the range of 0 < ϕ < 1.5 % . The flow is fully turbulent, and (RNG) k − ϵ turbulent model is used for the numerical analysis. The results reveal that strong turbulent kinetic energy and additional vortex flow through the cuts of the modified twisted tapes are the main reason for better fluid mixing and heat transfer enhancement. The heat transfer enhances about 14.5% for the case of ϕ = 1.5 % . Furthermore, using double V-cut twisted tapes improves the Nusselt number of the nanofluid flow inside heat exchangers about 138% compared to conventional twisted tape without cuts. The maximum value of the thermal performance η = 1.99 is achieved by using nanofluid with ϕ = 1.5 % and b / c = 1.8 at Re = 5000.