Analysis of Convective Heat Transfer and Pressure Drop Characteristics with Various Installation Conditions of a Quarter-Circle Obstacle in an Air-Based Solar Collector

Hyeonseok Jeong; Geonyong An; Taehwan Choi; Kwangam Moon; Byeonghwa An; Hwiung Choi

doi:10.7836/kses.2025.45.6.011

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2025 Vol.45, Issue 6 Preview Page Next Page

Research Article

Analysis of Convective Heat Transfer and Pressure Drop Characteristics with Various Installation Conditions of a Quarter-Circle Obstacle in an Air-Based Solar Collector 공기식 태양열 집열기 내 사분원 저항체 설치 조건에 따른 대류 열전달 및 압력강하 특성 분석

30 December 2025. pp. 11-24

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Abstract

Air-based solar collectors are renewable systems that produce heated air using solar thermal energy. However, the thermal efficiency of these systems must be increased because of the low thermal conductivity of air. In this study, the heat transfer and pressure drop characteristics of a developed air-based solar collector with quarter-circle-shaped obstacles on the upper and lower surfaces of an air channel were investigated. Computational fluid dynamics (CFD) was used to analyze the effects of the obstacle installation conditions on the heat transfer and pressure drop. The quarter-circle-shaped obstacle produced a 2.53-fold increase in heat transfer; however, the friction factor also increased 41.38 times. Therefore, the performance factor, which considers heat transfer enhancement and pressure drop, was also evaluated. The performance factor was highest at a Reynolds number of 3000 with installation conditions of e/H = 0.10 and P/e = 40, yielding a value of 1.16. Furthermore, empirical correlations for the Nusselt number and friction factor were developed based on the Reynolds number and obstacle installation conditions. The average absolute percentage errors between the CFD results and the from the correlations were 2.98% and 7.5%, respectively, indicating high agreement between the values.

Keywords

Solar thermal system

Air-based solar collector

Computational fluid dynamics

Heat transfer

Quarter-circle obstacle

키워드

태양열 시스템

공기식 태양열 집열기

전산유체해석

열전달

사분원 저항체

References

Energy Institute, Statistical Review of World Energy, 2023. https://www.energyinst.org/__data/assets/pdf_file/0004/1055542/EI_Stat_Review_PDF_single_3.pdf. last accessed on the 23^rd September 2025.

Korea Energy Agency, KEA Energy Handbook, 2024. https://www.energy.or.kr/energy_issue/mail_vol240/pdf/2024_KEA_02.pdf. last accessed on the 23^rd September 2025.

Shin, J. H. and Boo, J. H., A Numerical Study on the Thermal Performance of a Solar Air Heater Depending on the Hole Configuration and Geometry in the Absorber Plate, Journal of the Korean Solar Energy Society, Vol. 35, No. 1, pp. 69-80, 2015, https://doi.org/10.7836/kses.2015.35.1.069.

10.7836/kses.2015.35.1.069

Choi, H. U., Kim, Y. B., Yoon, J. I., Son, C. H., and Choi, K. H., Research on the Heat Transfer and Pressure Drop by Installation Conditions of Rectangular Obstacle in a Solar Air Heater Based on CFD, Journal of the Korean Solar Energy Society, Vol. 39, No. 1, pp. 77-89, 2019, https://doi.org/10.7836/kses.2019.39.1.077.

10.7836/kses.2019.39.1.077

Lee, T. J., Jeong, H. J., and Shin, D. H., Optimization of the Rib-Fin Shape of Solar Air Heater by CFD, 2021 Autumn Conference of the Korean Society of Mechanical Engineers, Vol. 39, No. 1, pp. 383-388, November 2021, Gwangju, Republic of Korea.

Kim, S. B., Moon, K. A., Choi, H. U., An, B. W., and Choi, K. H., Analysis of the Heat Transfer and Pressure Drop by the Turbulator Having a Non-Uniform Triangular Cross-Section in Air-Type PV/T Collector, Journal of the Korean Solar Energy Society, Vol. 43, No. 4, pp. 1-18, 2023, https://doi.org/10.7836/kses.2023.43.4.001.

10.7836/kses.2023.43.4.001

Bekele, A., Mishra, M., and Dutta, S., Performance Characteristics of Solar Air Heater with Surface Mounted Obstacles, Energy Conversion and Management, Vol. 85, pp. 603-611, 2014, https://doi.org/10.1016/j.enconman.2014.04.079.

10.1016/j.enconman.2014.04.079

Singh, S., Singh, B., Hans, V. S., and Gill, R. S., CFD (Computational Fluid Dynamics) Investigation on Nusselt Number and Friction Factor of Solar Air Heater Duct Roughened with Non-Uniform Cross-Section Transverse Rib, Energy, Vol. 84, pp. 509-517, 2015, https://doi.org/10.1016/j.energy.2015.03.015.

10.1016/j.energy.2015.03.015

Chand, S., Chand, P., and Ghritlahre, H. K., Thermal Performance Enhancement of Solar Air Heater Using Louvered Fins Collector, Solar Energy, Vol. 239, pp. 10-24, 2022, https://doi.org/10.1016/j.solener.2022.04.046.

10.1016/j.solener.2022.04.046

Alam, T., Development of Correlations of Nusselt Number and Friction Factor of Solar Thermal Collector Equipped with Hybrid Rib Roughness, Solar Energy Materials and Solar Cells, Vol. 272, 112887, 2024, https://doi.org/10.1016/j.solmat.2024.112887.

10.1016/j.solmat.2024.112887

Taghavi, A. and Aghdam, A. H., Thermo-Hydrodynamic Analysis of Various Curved Solar Air-Heaters with Boot-Shaped Ribs: CFD Simulations Coupled with an Optimized Artificial Neural Network Model, Applied Thermal Engineering, Vol. 267, 125750, 2025, https://doi.org/10.1016/j.applthermaleng.2025.125750.

10.1016/j.applthermaleng.2025.125750

An, G. Y., Moon, K. A., An, B. H., and Choi, H. U., CFD Analysis on the Heat Transfer and Pressure Drop Characteristics with Different Installation Location and Shapes of Obstacle in a Solar Air Heater, Journal of the Korean Solar Energy Society, Vol. 45, No. 3, pp. 47-59, 2025, https://doi.org/10.7836/kses.2025.45.3.047.

10.7836/kses.2025.45.3.047

Kumar, R., Geol, V., and Kumar, A., A Parametric Study of the 2D Model of Solar Air Heater with Elliptical Rib Roughness Using CFD, Journal of Mechanical Science and Technology, Vol. 31, pp. 959-964, 2017, https://doi.org/10.1007/s12206-017-0148-7.

10.1007/s12206-017-0148-7

ASHRAE Standard 93, Method of Testing to Determine the Thermal Performance of Solar Collectors, American Society of Heat, Refrigeration and Air Conditioning Engineers, Atlanta, GA, USA, 2003.

Singh, I., Vardhan, S., Singh, S., and Singh, A., Experimental and CFD Analysis of Solar Air Heater Duct Roughened with Multiple Broken Transverse Ribs: A Comparative Study, Solar Energy, Vol. 188, pp. 519-532, 2019, https://doi.org/10.1016/j.solener.2019.06.022.

10.1016/j.solener.2019.06.022

Kumar, R., and Goel V., Unconventional Solar Air Heater with Triangular flow-Passage: A CFD Based Comparative Performance Assessment of Different Cross-Sectional Rib-Roughnesses, Renewable Energy, Vol. 172, pp. 1267-1278, 2021, https://doi.org/10.1016/j.renene.2021.03.068.

10.1016/j.renene.2021.03.068

Haldar, A., Varshney, L., and Verma, P., Effect of Roughness Parameters on Performance of Solar Air Heater Having Artificial Wavy Roughness Using CFD, Renewable Energy, Vol. 184, pp. 266-279, 2022, https://doi.org/10.1016/j.renene.2021.11.088.

10.1016/j.renene.2021.11.088

Mahanand, Y. and Senapati, H. R., Thermo-hydraulic Performance Analysis of a Solar Air Heater (SAH) with Quarter-circular Ribs on the Absorber Plate a Comparative Study, International Journal of Thermal Sciences, Vol. 161, 106747, 2021, https://doi.org/10.1016/j.ijthermalsci.2020.106747.

10.1016/j.ijthermalsci.2020.106747

Webb, R. L. and Gee, D. L., Forced Convection Heat Transfer in Helically Rib-roughened Tubes, International Journal of Heat and Mass Transfer, Vol. 23, pp. 1127-1136, 1980, https://doi.org/10.1016/0017-9310(80)90177-5

10.1016/0017-9310(80)90177-5

Information

Publisher :Korean Solar Energy Society
Publisher(Ko) :한국태양에너지학회
Journal Title :Journal of the Korean Solar Energy Society
Journal Title(Ko) :한국태양에너지학회 논문집
Volume : 45
No :6
Pages :11-24
Received Date : 2025-10-16
Revised Date : 2025-10-21
Accepted Date : 2025-10-29
DOI :https://doi.org/10.7836/kses.2025.45.6.011

Journal of the Korean Solar Energy Society ISSN:1598-6411(Print) 2508-3562(Online) 한국태양에너지학회 논문집

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