Numerical Simulation of Fluid Flow and Heat Transfer in Enhance Twisted Elliptical Tubes

Abstract

This study is carried to find the thermal hydraulic efficiency of smooth twisted elliptical tubes and enhanced twisted elliptical tubes which has fins at both axes e.g. Major axis and the Mi-nor Axis of elliptical cross section of tubes. And each tube has five numbers of sub types with different values of twist pitch (e.g.62.5, 83.33, 125 and 150 mm). In this way a total 10 num-bers of tubes were generated. Water liquid is used as the working fluid. Reynolds number in this study ranges from 10000 to 50000. As flow is in turbulent regime, realizable K-ε turbu-lent model is used to simulate the flow in turbulent regime. Heat transfer mechanism is forced convection as the Test Section Wall has a constant outer temperature. Results shows that av-erage Nusselt number increase with increasing Reynolds number also Pressure drop increas-es. Enhanced twisted tube with 62.5 mm twist pitch shows the best thermal results compared to smooth elliptical tube. For Reynolds number 10000 to 20000 ETETB with 62.5mm pitch, for Reynolds number 20000 to 40000 ETETB with 83.33 mm and for 50000 Reynolds num-ber ETETB with 125mm pitch shows the best thermal hydraulic efficiency.