THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

Authors of this Paper

External Links

Yang Chen

,

Guofei Chen

,

Huijie Xu

,

Jianqiu Zhou

online first only

Numerical investigation of effect of fill ratio and inclination angle on a U-shaped elliptical gravity heat pipe thermal performance

ABSTRACT
As electronic devices become increasingly compact, effective thermal management is crucial for performance. This study establishes a model of a U-shaped elliptical gravity heat pipe with dual heating ends and a single cooling end. Through computational fluid dynamics (CFD) simulations, the impacts of filling ratio and inclination angle on the thermal transfer capacity for the heat pipe were investigated. The results indicate that the evaporator surface temperature and thermal resistance of the heat pipe initially decrease and then increase with an increasing filling ratio. Within the inclination range of 10° to 90°, the evaporator surface temperature and thermal resistance gradually decrease. The optimal filling ratio is found to be 65%, and the optimal inclination angle is 90°. Furthermore, it was observed that higher heat input intensifies the effects of filling ratio and inclination angle affecting heat pipe thermal performance. These findings highlight the critical role of these parameters in optimizing heat pipe performance under varying heat inputs.
KEYWORDS
U-shaped elliptical gravity heat pipe, filling ratio, inclination angle
PAPER SUBMITTED: 2024-11-13
PAPER REVISED: 2024-12-21
PAPER ACCEPTED: 2024-12-26
PUBLISHED ONLINE: 2025-02-16
DOI REFERENCE: https://doi.org/10.2298/TSCI241113023C
REFERENCES
  1. Du , S ., et al. , Simulation analysis on energy consumption and economy of CPU cooling system based on loop heat pipe for data center[J]. Thermal Science and Engineering Progress , 45( 2023 ) , 102115
  2. Wang , K . , et al. Numerical simulation on the heat transfer characteristics of two - phase loop thermosyphon with high filling ratios[J]. International Journal of Heat and Mass Transfer , 184( 2022 ) , 122311
  3. Alammar , A. A ., et al., Effect of inclination angle and fill ratio on geyser boiling phenomena in a two - phase closed thermosiphon - Experimental investigation[J]. Energy Conversion and Management , 156( 2018 ), pp. 150 - 166
  4. Li , G . , et al . Transient experimental and numerical st udy of thermosyphon under different heating fluxes and filling ratios[J]. Applied Thermal Engineering , 243( 2024 ) , 122514
  5. Kim , Y ., et al., Boiling and condensation heat transfer of inclined two - phase closed thermosyphon with various filling ratios[J]. Applied Thermal Engineering , 145( 2018 ) , pp. 328 - 342
  6. Alammar, A. A ., et al . , Numerical investigation of effect of fill ratio and inclination angle on a thermosiphon heat pipe thermal performance[J]. Applied Thermal Engineering , 108( 2016 ), pp. 1055 - 1065
  7. Xu , Z . , et al . , The influences of the inclination angle and evaporator wettability on the heat performance of a thermosyphon by simulation and experiment[J]. International Journal of Heat and Mass Transfer , 116( 2018 ) , pp. 675 - 684
  8. Anto , L. P . , Varghese , J . , Three - dimensional steady state numerical analysis of inclined two phase closed thermosyphon for solar applications[J]. Case Studies in Thermal Engineering , 30( 2022 ) , 101805
  9. Wu , Y . , et al . , Effect of the Inclination Angle on the Steady - State Heat Transfer Performance of a Thermosyphon[J]. Applied Sciences , 9( 2019 ), 3324
  10. Yuan , J . , et al. , Effect of non - condensable gas on thermal characteristics in two - phase closed thermosyphon[J]. Applie d Thermal Engineering , 173( 2020 ) , 115233
  11. Fadhl , B . , et al . , CFD modelling of a two - phase closed thermosyphon charged with R134a and R404a[J]. Applied Thermal Engineering , 78( 2015 ) , pp. 482 - 490
  12. Lu , J . , et al. , Experimental Study on Heat Transfer Characteristics of Thermosyphon with Methanol - Based Binary Working Fluid[J]. Iranian Journal of Science and Technology, Transactions of Mechanical Engineering , 2023 , pp. 1 - 13
  13. Amatachaya , P . , Srimuang , W . , Comparative heat transfer characteristics of a flat two - phase closed thermosyphon (FTPCT) and a conventional two - phase closed thermosyphon (CTPCT)[J]. International Communications in Heat and Mass Transfer , 37( 2010 ) , pp. 293 - 298
  14. Singh, R . R . , et al . , Effect of anodization on the heat transfer performance of flat thermosyphon[J]. Experimental Thermal and Fluid Science , 68 (2015), pp. 574 - 581
  15. Naresh , Y . , Balaji , C . , Experimental investigations of heat transfer from an internally finned two phase closed thermosyphon[J]. Applied Thermal Engineering , 112 (2017), pp. 1658 - 1666
  16. Emam , M . , et al. Performance improvement of single - junction photovoltaic systems using a n ew design of a heat pipe - based heat sink: Experimental study[J]. Applied Thermal Engineering , 219( 2023 ) , 119653
  17. Hussein ., H . M. S ., et al., Performance of wickless heat pipe flat plate solar collectors having different pipes cross sections geometries and filling ratios[J]. Energy Conversion and Management , 47( 2006 ) , pp. 1539 - 1549
  18. Tao , J . , et al . , Experimental study on liquid charging levels of elliptical gravity heat pipes [J]. Journal of Huazhong University of Science and Technology , 6 ( 1989 ) , pp. 7 - 11. (in Chinese language)
  19. Tao , J . , et al . , Study on the heat transfer characteristics of elliptical gravity heat pipes [J]. Journal of Huazhong University of Science and Technology , 3 ( 1990 ) , pp. 39 - 44. (in C hinese language)
  20. Brackbill , J. U. , et al., A continuum method for modeling surface tension[J]. Journal of Computational Physics , 100(1992), pp. 335 - 354
  21. Su, Z . , et al. , Investigation of improved VOF method in CFD simulation of sodium heat pipes using a multi - zone modeling method [J] . International Communications in Heat and Mass Transfer 157 (2024) , 107669. [2 2 ] Liu, H . , et al. , An assessment and analysis of phase change models for the simulation of vapor bubble condensation [J] . International Journal of Heat and Mass Transfer , 157 (202 0) , 119924
  22. Tang, J . , et al. , A machine - learning based phase change model for simulation of bubble condensation [J] . International Journal of Heat and Mass Transfer , 178 (2021) , 121620
  23. Wang, K., et al., Investigation of heat transfer and flow characteristics in two - phase loop thermosyphon by visualization experiments and CFD simulations [J] . International Journal of Heat and Mass Transfer 203 (2023), 123812
  24. Ding, L., et al., A modified dynamic Lee model for two - phase closed thermosyphon (T PCT) simulation [J] . Numerical Heat Transfer, Part B: Fundamentals , 85 (2024) , pp. 1041 - 1055
  25. Alizadehdakhel, A., et al., CFD modeling of flow and heat transfer in a thermosyphon[J]. International Communications in Heat and Mass Transfer , 37(2010), pp. 312 - 318. [2 7 ] Abdullahi, B., Development and Optimization of heat pipe based Compound Parabolic Collector [D] . University of Birmingham, 2015
PDF VERSION [DOWNLOAD]
Numerical investigation of effect of fill ratio and inclination angle on a U-shaped elliptical gravity heat pipe thermal performance