Thermal characterization in circular tube inserted with diamond-shaped rings

Main Article Content

P. Promthaisong
S. Skullong

Abstract

The article presents the influence of diamond-shaped rings (DRs) mounted repeatedly in a uniform heat-fluxed heat exchanger tube on flow resistance and thermal behaviors. In the current study, the DR elements used for producing the longitudinal vortex flows were placed in the tube by employing two small rods to connect the DRs together. Effects of three relative ring-pitches or pitch ratios (RP = P/D = 0.5, 1.0, 2.0) and three ring blockage ratios (RB = b/D = 0.1, 0.15 and 0.2) at the attack angle of 45° on Nusselt number (Nu), friction factor (f) and thermal enhancement factor (TEF) in turbulence regimes, Reynolds number (Re) between 4220–25,800 are examined. The results have shown that the heat transfer and pressure loss increase considerably with raising RB but with the decline of RP. The maximum Nu and f obtained at RB = 0.2 and RP = 0.5 are, respectively, about 3.21–4.18 and 11.73–32.85 times above the smooth tube. The highest TEF around 1.57 is seen at RB = 0.10 and RP = 1.0. Furthermore, empirical correlations for Nu, f and TEF were established and found to fit the experimental data with deviations within ±8%, ±9% and ±5%, respectively.

Downloads

Download data is not yet available.

Article Details

How to Cite
Promthaisong, P., & Skullong, S. (2019). Thermal characterization in circular tube inserted with diamond-shaped rings. Journal of Research and Applications in Mechanical Engineering, 7(1), 1–10. Retrieved from https://ph01.tci-thaijo.org/index.php/jrame/article/view/174289
Section
RESEARCH ARTICLES

References

[1] Sneha, P., Subrahmanyam T. and Naidu S.V. A comparative study on the thermal performance of water in a circular tube with twisted tapes, perforated twisted tapes and perforated twisted tapes with alternate axis, Int. J. Therm. Sci., Vol. 136, 2019, pp. 530-538.

[2] Keklikcioglu, O. and Ozceyhan, V. Experimental investigation on heat transfer enhancement in a circular tube with equilateral triangle cross sectioned coiled-wire inserts, Appl. Therm. Eng., Vol. 131, 2018, pp. 686-695.

[3] Skullong, S., Promvonge, P., Jayranaiwachira, N. and Thianpong, C. Experimental and numerical heat transfer investigation in a tubular heat exchanger with delta-wing tape inserts, Chem. Eng. Process. Process Intensif., Vol. 109, 2016, pp. 164-177.

[4] Suwannapan, S., Skullong, S. and Promvonge, P. Thermal characteristics in a heat exchanger tube fitted with zigzag‐winglet perforated‐tapes, J. Res. Appl. Mech. Eng., Vol. 3, 2015, pp. 29-36.

[5] Skullong, S., Promvonge, P., Thianpong, C. and Pimsarn, M. Heat transfer and turbulent flow friction in a round tube with staggered-winglet perforated-tapes, Int. J. Heat Mass Transf., Vol. 95, 2016, pp. 230-242.

[6] Promvonge, P., Koolnapadol, N., Pimsarn, M. and Thianpong, C. Thermal performance enhancement in a heat exchanger tube fitted with inclined vortex rings, Appl. Therm. Eng., Vol. 62, 2014, pp. 285-292.

[7] Chingtuaythong, W., Promvonge, P., Thianpong, C. and Pimsarn, M. Heat transfer characterization in a tubular heat exchanger with V-shaped rings, Appl. Therm. Eng., Vol. 110, 2017, 1164-1171.

[8] Promvonge, P. Thermal performance in circular tube fitted with coiled square wires, Energy Convers. Manage., Vol. 49, 2008, pp. 980-987.

[9] Chiu, Y.W. and Jang, J.Y. 3D numerical and experimental analysis for thermal–hydraulic characteristics of air flow inside a circular tube with different tube inserts, Appl. Therm. Eng., Vol. 29, 2009, pp. 250-258.

[10] Promvonge, P., Pethkool, S., Pimsarn, M. and Thianpong, C. Heat transfer augmentation in a helical-ribbed tube with double twisted tape inserts, Int. Commun. Heat Mass Transf., Vol. 39, 2012, pp. 953-959.

[11] Hong, Y., Du, J. and Wang, S. Turbulent thermal, fluid flow and thermodynamic characteristics in a plain tube fitted with overlapped multiple twisted tapes, Int. J. Heat Mass Transf., Vol. 115, 2017, pp. 551-565.

[12] Man, C., Lv, X., Hu, J., Sun, P. and Tang, Y. Experimental study on effect of heat transfer enhancement for single-phase forced convective flow with twisted tape inserts, Int. J. Heat Mass Transf., Vol. 106, 2017, pp. 877-883.

[13] Kongkaitpaiboon, V., Nanan, K. and Eiamsa-ard, S. Experimental investigation of convective heat transfer and pressure loss in a round tube fitted with circular-ring turbulators, Int. Commun. Heat Mass Transf., Vol. 37, 2010, pp. 568-574.

[14] Promvonge, P., Tamna, S., Pimsarn, M. and Thianpong, C. Thermal characterization in a circular tube fitted with inclined horseshoe baffles, Appl. Therm. Eng., Vol. 75, 2015, pp. 1147-1155.

[15] Skullong, S., Promvonge, P., Thianpong, C., Jayranaiwachira, N. and Pimsarn, M. Thermal performance of heat exchanger tube inserted with curved-winglet tapes, Appl. Therm. Eng., Vol. 129, 2018, pp. 1197-1211.

[16] ANSI/ASME, Measurement uncertainty, PTC 19.1-1985, Part I, 1986, ASME, New York.

[17] Skullong, S., Promvonge, P., Thianpong, C., Jayranaiwachira, N., Pimsarn, M. Heat transfer augmentation in a solar air heater channel with combined winglets and wavy grooves on absorber plate, Appl. Therm. Eng., Vol. 122, 2017, pp. 268-284.

[18] Incropera, F. and Dewitt, P.D. Fundamentals of heat and mass transfer, 6th edition, 2007, Wiley, USA.