Numerical Solution of the Effect of Increasing the Wall Temperature on Flow and Heat Transfer in Pulsating Heat Pipe

Document Type : Mechanics article

Authors

1 Assistant Professor of Mechanical Engineering, Bu-Ali Sina University, Department of Mechanical Engineering, Hamedan, I. R. Iran

2 Graguated

Abstract

In this paper the effects of increasing the wall temperature and the amount of liquid charge on the oscillating flow in a U-shaped miniature tube, with a simple bend of diameter 1.5 mm and closed end investigated. The governing equations are obtained by applying the conservation of mass, momentum and energy for the liquid slug and the vapor plugs. A complete numerical simulation has been performed to investigate the effects of wall temperature and the amount of liquid charge on the heat pipe performance using explicit method. The obtained results show that by increasing the walls temperature difference, amplitude of oscillations of the liquid slug, sensible and latent heat transfer will be increased, as the temperature difference is increased by only ,oscillation amplitude of the liquid slug about 8 mm, the sensible heat transfer 4 watts and the latent heat transfer watts increases. Additionally, by increasing the charge rate, the oscillation amplitude and the sensible heat transfer are significantly reduced, for example, increasing the charge rate from 30 to 50% reduces the oscillation amplitude by about 65 mm as well as the sensible heat transfer by 87 watts reduces. In the charging ratio 90%, the heat pipe operation is stopped.

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[1] مسعود ضیائی راد، مریم بیگی هرچگانی، " مطالعه عددی انتقال حرارت و افت فشار در جریان اجباری نانوسیال داخل لوله دندانه دار "، نشریه مدل‌سازی در مهندسی، دوره 15، شماره 49، تابستان 1396، صفحه 65-76.
[2] قنبر علی شیخ زاده، سید پیام غفاری، " مدل سازی عددی اثر انتقال نانو ذرات در جریان جابه جایی ترکیبی نانوسیال با خواص متغیر در محفظه مربعی با درگاه ورود و خروج جریان"، نشریه مدل‌سازی در مهندسی، دوره 12، شماره 38، پاییز 1393، صفحه 102-83.
[3] مسعود ضیائی راد، پیمان الیاسی، " بررسی عددی جریان نوسانی نانوسیال در کانال مستطیلی شکل در حالت غیردائم "، نشریه مدل‌سازی در مهندسی، دوره 14، شماره 44، بهار 1395، صفحه 34-21.
[4] Y. Zhang, A. Faghri, "Advances and unsolved Issues in pulsating heat pipes", Heat Transfer Engineering, Vol. 29, No. 1, 2008, pp. 20-44.
[5] W. Shao, Y. Zhang, "Effects of capillary and gravitational forces on performance of an oscillating heat pipe", Frontiers in Heat Pipes (FHP), Vol. 2, No. 2, 2011, pp.1-7.
[6] T. N. Wong, B. Y. Tong, S. M. Lim, and K.T. Ooi, "Theoretical modeling of pulsating heat pipe", Proceeding of  11th International Heat Pipe Conference, Tokyo, Japan, 1999, pp. 159- 163.
[7] R. Dobson, T. Harms, "Lumped parameter analysis of closed and open oscillatory heat pipe", Proceeding of 11th International Heat Pipe Conference, Tokyo, Japan, 1999, pp. 137-142.
[8] Y. Zhang, A. Faghri, "Heat transfer in a pulsating heat pipe with open end", International Journal of Heat and Mass Transfer, Vol. 45, No. 4, 2002, pp. 755-764.
[9] M. Shaffi, A. Faghri, and Y. Zhang, "Thermal modeling of  unlooped and looped pulsating heat pipes", Journal of  Heat Transfer, Vol. 123, No. 6, 2001, pp. 1159–1172.
 [10] H. B. Ma, M. A. Hanlon, and C. L. Chen, "An Investigation of oscillating motions in a miniature pulsating heat Pipe", Microfluidics and Nanofluidics, Vol. 2, No. 2, 2006, pp. 171-179.
[11] V. M. Kiseev, K. A. Zolkin, "The influence of acceleration on the performance of oscillating heat pipe", Proceeding of 11th International Heat Pipe Conference, Tokyo, Japan, 1999, pp. 154-158.
[12] W. Shao, Y. Zhang, "Thermally- induced oscillatory flow and heat transfer in an oscillating heat pipe", Journal of Enhanced Heat Transfer, Vol. 18, No. 3, 2011, pp. 177-190.
[13] K. R. Narasimha, S. N. Sridhara, M. S. Rajagopal and K. N. Seetharamu, "Influence of heat input, working fluid and evacuation level on the performance of pulsating heat pipe", Journal do Applied Fluid Mechanics, Vol. 5, No. 2, 2012, pp. 33-42.
[14] M. Mameli, M. Marengo, and S. Khandekar, "Local heat transfer and thermo- fluid characterization of pulsating heat pipe' International Journal of Thermal Science, Vol. 75, 2014, pp.140-152.
[15] H. Alizadeh, R. Ghasempour, M. B. Shafii and M. H. Ahmadi, "Numerical simulation of PV cooling by using turn pulsating heat pipe" International Journal of Heat and Mass Transfer, Vol. 27, 2018, pp. 203-208.
[16] R. Nemati, M. B. Shafii, "Advanced heat transfer analysis of a U- shaped pulsating heat pipe considering evaporative liquid film trailing from its liquid slug" Applied Thermal Engineering, Vol. 138, 2018, pp. 475-489.
[17] M. Mobadersani, S. Jafarmadar and R. Rezavand "Modeling of a single turn pulsating heat pipe based on flow boiling and condensation phenomena" International Journal of Engineering, Vol. 32, No. 4, 2019, pp. 569-579.
[18] A. Bejan, Convection Heat Transfer, 2nd edition, John Wiley & Sons, Incorporated, New York, 1995.
[19] Y. Zhang, A. Faghri, and M. B. Shafii, "Analysis of liquid-vapor pulsating flow in a U-shaped miniature tube", International Journal of Heat and Mass Transfer, Vol. 45, No. 12, 2002, pp. 2501-2508.