Thermal-hydrodynamic analysis for internally finned tubes: Experimental, numerical and performance evaluation study
Authors:O. H. Salem, Ahmed Hegazy, K. Yousef
Volume 11, Issue 2, Paper No. 110203
Abstract
The characteristics of heat transfer and fluid flow of an internally continuously finned tube were studied, experimentally and numerically, and a performance evaluation study was conducted. The numerical results were validated with the current experimental data as well as other published data, with a maximum deviation of 4.65%. The effect of different key parameters like fin height, number of fins, and fin thickness on the thermal-hydrodynamic performance was studied. The study reveals that increasing both fin height, which is the most effective parameter, and number of fins raises the heat transfer coefficient and friction factor values, but fin thickness negligibly affects the performance. Notably, the average heat transfer coefficient and friction factor values rise by 40.92 % and 18.4 %, respectively, if the fin height to diameter ratio is increased from 0.1786 to 0.4018, and by 35.4 % and 13.5 %, respectively, if the number of fins is increased from 2 to 6, compared to smooth tubes under a mass flow rate of 0.3 kg/s. Furthermore, the thermal enhancement factor, which is the ratio between the heat transfer coefficient and friction factor for the enhanced tube as opposed to the smooth one, increases by 33.27%, 48.64%, and 8.71% if the fin height, number of fins, and fin thickness increase by 125%, 300%, and 200%, respectively, under constant mass flow rate condition. While the thermal enhancement factor decreases by 22.89%, 74.53%, and 7.92% if the fin height, number of fins, and fin thickness increase by 125%, 300%, and 200%, respectively, under constant pressure drop condition. In the case of constant pumping power condition, the thermal enhancement factor hovers around unity for fin height and thickness, and it decreases by 23.89% if the number of fins increases by 300%.
Keywords: continuously finned tube, thermal-hydrodynamic performance,
heat transfer applications
110203_Salem