Heat transfer and fluid flow performance of an internally longitudinal finned tube: Numerical study and experimental validation

Abstract

The characteristics of heat transfer and fluid flow of an internally longitudinal finned tube were numerically studied. The results were validated with published experimental data, comparing the heat transfer coefficient (h) and friction factor (f) calculated in our numerical study with the corresponding values obtained from experimental data, with a highest deviation of 6.3%. Exploring a novel hollow longitudinal fin design to enhance heat transfer and reduce pressure drop, while investigating key parameters like fin angle (θ), inscribed diameter (dins), and fin thickness (δ). Through comprehensive analysis, valuable insights are offered into optimizing thermal performance compared to traditional smooth tube configurations. The study reveals that a rise in Re leads to a rise in heat transfer coefficient and a reduction in friction factor. Notably, in the case of internally finned tubes at θ=30⁰,dins=10mm,andδ=0.5mm, the handf are 0.32−0.9and0.34−0.43 times higher, respectively, compared to smooth tubes under a constant mass flow rate ranging from 10kg/hto60kg/h. Furthermore, variations in dins impact the handf for internally finned tubes, with a decrease in dins resulting in increased handf. Specifically, at D/dins = 8, the handf exceed those of smooth tubes by 0.357−1.16and1.097−1.608 times, respectively, under a constant mass flow rate across the same range. Additionally, the study investigates the effects of δ on internally finned tubes, showing that as the δ increases, the handf increase. In the case of θ=30⁰,dins=10mm,andδ=2.5mm, the handf increase to 1.51−1.75and1.29−1.87 times higher, respectively, compared to smooth tubes under a constant mass flow rate from 10 kg/h to 60 kg/h.