In the present work, a numerical study of the possibility of increasing the thermal-hydraulic performance of drop-shaped tube bundles was carried out by controlling the angle of attack θ from 0° to 360°. The Reynolds number Re ranged from 1780 to 18700. Ten cases of twenty-row circular and drop-shaped tube bundles in in-line and staggered arrangement were considered. The results of numerical simulation showed that the maximum values of the thermal-hydraulic performance can be achieved for a number of studied bundles, while the best ones were for the case 6 (θ_(1-5)=0°, θ_(6-10)=330°, θ_(11-15)=30°, θ_(16-20)=0°), which were greater by 65.9 – 71.54% and 63.18 – 75.93% than those for the case 3 (staggered drop-shaped tube bundle, θ_(1-20)=0°) and case 1 (staggered circular tube bundle), respectively. Formulas was developed for calculating the average Nusselt number and thermal-hydraulic performance for case 6 with a maximum deviation of 0.74% and 0.48%, respectively.
Повышение эффективности пучков каплевидных труб за счет управления углом атаки
В настоящей работе проведено численное исследование возможности повышения термогидродинамической эффективности пучков каплевидных труб за счет управления углом атаки θ от 0° до 360°. Исследование характеристик теплообмена проводилось в диапазоне чисел Рейнольдса от 1780 до 18700. Рассмотрены десять случаев пучков труб круглой и каплевидной формы с коридорным и шахматным расположением. Результаты численного моделирования показали, что максимальные значения общей теплогидродинамической эффективности могут быть достигнуты для ряда исследованных конфигураций, при этом наиболее удачные – для случая 6 (θ_(1-5)=0°, θ_(6-10)=330°, θ_(11-15)=30°, θ_(16-20)=0°) превышают на 65,9 – 71,54 % и 63,18 – 75,93 %, наименее удачные конфигурации, как в случае 3 (шахматный пучок каплевидных труб, θ_(1-20)=0°) и в случае 1 (шахматный пучок круглых труб), соответственно. Разработаны формулы для расчета среднего числа Нуссельта и эффективности для случая 6 с максимальным отклонением 0,74 % и 0,48%, соответственно.
1. Chatterjee D., Mondal B., “Unsteady mixed convection heat transfer from tandem square cylinders in cross flow at low Reynolds numbers,” Heat Mass Transfer, Vol. 49, 2013, P. 907–20. 2. Zhukauskas A., “Heat transfer from tubes in cross-flow,” Adv. Heat Transf., Vol. 8, 1972, Pp. 93–160. 3. Bahaidarah H.M.S., Anand N.K., Chen H.C., “A numerical study of fluid flow and heat transfer over a bank of flat tubes,” Num. Heat Trans. Part A: Appl., Vol. 48, 2005, P. 359–385. 4. Toolthaisong S., Kasayapanand N., “Effect of Attack Angles on Air Side Thermal and Pressure Drop of the Cross Flow Heat Exchangers with Staggered Tube Arrangement,” Energy Procedia, Vol. 34, 2013, Pp. 417-429. 5. Alawadhi E.M., “Laminar forced convection flow past an in-line elliptical cylinder array with inclination,” J. Heat Transfer, Vol. 132, 2010, 071701. 6. Zhukova Y.V., Теrekh A.М., Rudenko A.I., “Convective heat transfer and drag of two side-by-side tubes in the narrow channel at different Reynolds number,” Doklady of the National Academy of Sciences of Belarus, Vol. 62, Iss. 6, 2018, Pp. 756-762. 7. Deeb R., Sidenkov D.V., “Numerical analysis of heat transfer and fluid flow around circular and non-circular tubes,” IOP Conf. Series J. Phys, 2088, 2021, 012008. 8. Deeb R., “Effect of angle of attack on heat transfer and hydrodynamic characteristics for staggered drop-shaped tubes bundle in cross-flow,” Proceedings of the Russian higher school Academy of sciences, V.48, iss. 3, 2020, Pp. 21 – 36. 9. Sayed A. et al., “Effect of attack and cone angels on air flow characteristics for staggered wing shaped tubes bundle,” Heat and Mass Transfer, Vol. 51, 2015, Pp.1001–1016. 10. Deeb R., “Comparative analysis of the latest improvements in heat transfer and hydrodynamic characteristics of smooth tubes in cross flow,” Thermal processes in engineering, V.13, iss. 2, 2021, Pp. 50 – 69. 11. Deeb R., “The Effect of Angle-of-Attack on Heat Transfer Characteristics of a Single Drop-Shaped Tube,” Physical-Chemical Kinetics in Gas Dynamics, Vol. 22, iss. 5, 2021, Pp. 43-63. 12. Deeb R., “Thermal-aerodynamic characteristics of staggered mixed tubes bundle composed of circular and drop-shaped tubes,” Physical-Chemical Kinetics in Gas Dynamics, Vol. 23, iss. 2, 2022, Pp. 15-37. 13. Deeb R., “Numerical analysis of the effect of longitudinal and transverse pitch ratio on the flow and heat transfer of staggered drop-shaped tubes bundle,” Int. J. Heat Mass Transfer, Vol. 183, 2022, 122123. 14. Deeb R., “Prediction of Heat Transfer Characteristics of Single and Multi-Row Staggered Drop Tube Heat Exchangers,” Thermal processes in engineering, V.14, iss. 9, 2022, Pp. 410 – 419. 15. ANSYS Fluent Reference Guide. ANSYS. Inc. Release 16.0. 2015.
