A new approach to thermo- Fluid behavior through porous layer of heat pipes

Document Type : Article

Author

School of Mechanical Engineering, Sharif University of Technology, Tehran, Iran

Abstract

This paper developed a new mathematical model to investigate the heat transfer as well as wick thickness of a heat pipe. The model was set up by conservative equations of continuity, momentum and energy in the thermal boundary layer. Using the similarity variable, the governing equations have been changed to a set of ordinary differential equations and they were solved numerically by the forth order Runge-Kutta method. The flow variables such as velocity components, wick thickness and Nusselt number were obtained. The results show that the Nusselt number is proportional to the root square root of the Darcy-modified Rayleigh number and that the distance from the edge of the condenser surface.  Furthermore, the thickness of the wick material depends on the Jakob number and proportional to the heat transfer between the wall and the liquid film.

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References
1. Chi, S.W., Heat Pipe Theory and Practice: a Sourcebook
(Series in Thermal and Fluids Engineering),
McGraw-Hill Inc., USA (1976).
2. Peterson, G.P., An Introduction to Heat Pipes: Modeling,
Testing, and Applications, John Wiley & Sons,
Inc., New York (1994).
3. Chung, W.B., Hwang, S.H., Park, C.M., Kim, Y.S.
and Kim, S.S., Development of Loop Heat Pipes with
c Using Cold Isostatic Press Method, Joint 18th IHPC
and 12th IHPS, Jeju, Korea, June 12-16 (2016).
4. Byon, C. and Kim, S.J. Permeability of mono- and
bi-dispersed porous media", EPJ Web of Conferences,
45, 01018 (2013).
5. Yang, X., Lu, T.J. and Kim, T. An analytical model
for permeability of isotropic porous media", Physics
Letters A., 378(30-31), pp. 2308-2311 (2014).
6. Tang, Y., Hu, Z., Qing, J., Xie, Z., Fu, T., and Chen,
W. Experimental investigation on isothermal performance
of the micro-grooved heat pipe", Experimental
Thermal and Fluid Science, 47, pp. 143-149, (2013).
7. Lefevre, F., Conrardy, J.B., Raynaud, M., and Bonjour,
J. Experimental investigations of
at plate heat
pipes with screen meshes or grooves covered with
screen meshes as capillary structure", Applied Thermal
Engineering, 37, pp. 95-102, (2012).
8. Kempers, R., Ewing, D., and Ching, C.Y. E ect of
number of mesh layers and
uid loading on the performance
of screen mesh wicked heat pipes", Applied
Thermal Engineering, 26(5-6), pp. 589-595 (2006).
9. Jiang, L., Ling, J., Jiang, L., Tang, Y., Li, Y.,
Zhou, W., and Gao, J. Thermal performance of a
novel porous crack composite wick heat pipe", Energy
Conversion and Management, 81, pp. 10-18 (2014).
10. Hsieh, J.C., Huang, H.J., and Shen, S.C. Experimental
study of micro rectangular groove structure covered
with multi mesh layers on performance of
at plate
heat pipe for LED lighting module", Microelectronics
Reliability, 52(6), pp. 1071-1079 (2012).
11. Dai, X., Famouri, M., Abdulagatov, A.E., Yang, R.,
Lee, Y.C., George, S.M., and Li, C. Capillary evaporation
on micro membrane-enhanced microchannel
wicks with atomic layer deposited silica", Applied
Physics Letters, 103(15), p. 151602 (2013).
12. Huang, G., Abdulshaheed, A., Chang, W., and Li,
C. An evaluation of hybrid wick design on high
performance copper-ethanol heat pipes", Joint 18th
IHPC and 12th IHPS, Jeju, Korea, June 12-16 (2016).
13. Reilly, S., and Catton, I. Utilization of pore-size
distributions to predict thermophysical properties and
performance of biporous wick evaporators", Journal of
Heat Transfer, ASME, 136(6), 061501, (2014).
14. Carey, V.P. Liquid-Vapor Phase-Change Phenomena,
Hemisphere, New York (1992).
15. Ren, C., Wu, Q.S., and Hu, M.B. Heat transfer with

ow and evaporation in loop heat pipe's wick at low
or moderate heat
uxes", Int. J. of Heat Mass Trans.,
Elsevier, 50(11-12), pp. 2296-2308 (2007).