Investigation of Thermo-Hydraulic Behavior of Flow in a Heat Exchanger Pipe using Double Perforated Twisted Tapes and Al2O3 Nano-Fluid

In this paper, Thermo-hydraulic behavior of flow in a heat exchanger pipe is investigated numerically and optimum geometry for the double perforated twisted tape turbulators and nano-fluid which produces the maximum thermal enhancement factor is determined. The analysis has been carried out for a flow range of Re= 10000 – 30000 and three different pitches with four different volume concentration of Al2O3 nano-fluid. Due to the twofold effect of turbulators on thermo-hydraulic behavior, thermal enhancement factor concepts are employed, which stands for both heat transfer rate and friction factor. Results show that maximum increase in Nu occurs at Re= 30000 and pitch ratio of 2.5 which is around 3% and the least increase occurs for pitch ratio of 4 at Re = 10000. The thermal enhancement factor decreases with increase of Re for all different pitch ratio and it is maximum value for pitch ration of 2.5, 3.25 and 4 are 1.72, 1.64 and 1.61 respectively. Also, thermal performance factor in creases with the increase of volume concentration of nanoparticles