การเปรียบเทียบลักษณะการถ่ายเทความร้อนบนพื้นผิวของแผ่นครีบธรรมดาและโค้งงอ

Ibroheng  Piya; Chayut  Nuntadusit

Authors

Ibroheng Piya Department of Mechanical Engineering, Faculty of Engineering, Princess of Naradhiwas University, Mueang Narathiwat District, Narathiwat 96000
Chayut Nuntadusit Department of Mechanical and Mechatronics Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla, 90110

Keywords:

Plain fins, Bending fin baffles, Thermo liquid crystal sheet, Heat transfer enhancement.

Abstract

This article presents an experimental investigation into the heat transfer characteristics on the surface of Plain Fins and Bending Fin Baffles, both having a total length of 2H and a thickness of 2 mm. Here, H represents the fin height, which is equal to the channel height (32 mm). The fins were designed with equal length and height dimensions, while the curved fin was bent at an angle of 120°. The fins were installed with longitudinal spacings of W = 64 mm and W = 32 mm between the upstream and downstream edges, respectively. A staggered arrangement of the fins was employed. The experiments were conducted within a Reynolds number range of Re_H = 10,000–24,000. In this study, the heat transfer distribution on the surface was measured using Thermo Liquid Crystals (TLCs) to visualise and determine the local Nusselt number (Nu) distribution. Pressure taps were also installed along the sidewalls of the channel to measure the pressure drop, which was subsequently used to calculate the friction factor and the thermal performance factor (TPF). The results indicated that the curved fin configuration enhanced the Nusselt number compared with the plain fin arrangement, and the overall thermal performance factor was found to be greater than 1 in all cases.

References

Z. H. Ayub, “Plate heat exchanger literature survey and new heat transfer and pressure drop correlations for refrigerant evaporators,” Heat Transfer Engineering, vol. 24, no. 5, 3–16, 2003, doi.org/10.1080/01457630304056

S. S. Mehendale, A. M. Jacobi, and R. K. Shah, “Fluid flow and heat transfer at micro- and meso-scales with application to heat exchanger design,” Applied Mechanics Reviews, vol. 53, no. 7, 175–193, 2000, doi.org/10.1115/1.3097347

S. G. Kandlikar, S. Garimella, D. Li, S. Colin, and M. R. King, Heat transfer and fluid flow in mini-channels and microchannels, 2nd ed., Elsevier, 2014.

B. X. Wang and X. F. Peng, “Experimental investigation on liquid forced-convection heat transfer through microchannels,” International Journal of Heat and Mass Transfer, vol. 37, no. 1, 73–82, 1994, doi.org/ 10.1016/0017-9310(94)90011-6

X. F. Peng and G. P. Peterson, “The effect of thermos fluid and geometrical parameters on convection of liquids through rectangular microchannels,” International Journal of Heat and Mass Transfer, vol. 38, no. 4, 755–758, 1995, doi.org/10.1016/0017-9310(95)93010-F

X. F. Peng and G. P. Peterson, “Convective heat transfer and flow friction for water flow in microchannel structures,” International Journal of Heat and Mass Transfer, vol. 39, no. 12, 2599–2608, 1996, doi.org/10.1016/0017 -9310(95)00327-4

A. R. Wieting, “Empirical correlations for heat transfer and flow friction characteristics of rectangular offset-fin plate-fin heat exchangers,” ASME Journal of Heat Transfer, vol. 97, no. 3, 488–490, 1975, doi.org/10.1115/1. 3450412

S. Mochizuki, Y. Yagi, and W. J. Yang, “Transport phenomena in stacks of interrupted parallel-plate surfaces,” Experimental Heat Transfer, vol. 1, no. 2, 127–140, 1987, doi.org/10.1080/0891615870894 6336

R. M. Manglik and A. E. Bergles, “Heat transfer and pressure drop correlations for the rectangular offset strip fin compact heat exchanger,” Experimental Thermal and Fluid Science, vol. 10, no. 2, 171–180, 1995, doi.org/ 10.1016/0894-1777(94)00096-Q

R. Song, M. Cui, and J. Liu, “A correlation for heat transfer and flow friction characteristics of the offset strip fin heat exchanger,” International Journal of Heat and Mass Transfer, vol. 115, 695–705, 2017, doi.org/10. 1016/j.ijheatmasstransfer.2017.08.054

N. C. DeJong and A. M. Jacobi, “Local flow and heat transfer behavior in convex-louver fin arrays,” ASME Journal of Heat Transfer, vol. 121, no. 1, 136–147, 1999, doi.org/10.1115/ 1.2825926

C. J’oen, A. M. Jacobi, and M. De Paepe, “Flow visualisation in inclined louvered fins,” Experimental Thermal and Fluid Science, vol. 33, no. 4, 664–674, 2009, doi.org/10.1016/j.exp thermflusci.2009.01.003

S. Chingulpitak, H. S. Ahn, L. G. Asirvatham, and S. Wongwises, “Fluid flow and heat transfer characteristics of heat sinks with laterally perforated plate fins,” International Journal of Heat and Mass Transfer, vol. 138, 293–303, 2019, doi.org/10.1016/j.ijheatmasstransfer. 2019.04.027

H. M. Joshi and R. L. Webb, “Heat transfer and friction in the offset strip fin heat exchanger,” International Journal of Heat and Mass Transfer, vol. 30, no. 1, 69–84, 1987, doi.org/ 10.1016/0017-9310(87)90061-5