Enhanced heat transfer in the convergent rectangular channels with ∧/∨-shaped ribs on one wall Lee, Myung-Sung; Yu, Ji-Ui; Jeong, Hee-Jae; Choi, Dong-Geun; Ha, Dong-Jun; Go, Jin-Su; Ahn, Soo-Whan;
The effect of the rib angle-of-attack on heat transfer in the convergent channel with -shaped ribs was examined experimentally. Four differently angled ribs (a = , , , and ) were placed to only the one sided wall. The ribbed wall was manufactured with a fixed rib height (e) of 10 mm and rib spacing (p)-to-height (e) ratio of 10. The convergent channel had a length of 1,000 mm and a cross-sectional areas of at inlet and at exit. The measurement was conducted for the Reynolds numbers ranging from 22,000 to 75,000. The results show that the Nusselt number is generally higher at higher Reynolds number and that an angle-of-attack of at the -shaped rib produces the greatest Nusselt number.
S. W. Ahn, H. K. Kang, S. T. Bae, and D. H. Lee, "Heat transfer and friction factor in a square channel with one, two, and four ribbed walls," ASME Journal of Turbomachinery, vol. 130, 034501-5, pp. 1-5, 2008.
J. C. Han, S. Ou, J. S. Park, and C. Lei, "Augmented heat transfer in rectangular channels of narrow aspect ratios with rib turbulators," International Journal of Heat and Mass Transfer, vol. 32, no. 9, pp. 1619-1630, 1989.
A. E. Momin, J. Saini, and S. Solanki, "Heat transfer and friction in solar air heater duct with V-shaped rib roughness on absorber plate," International Journal of Heat and Mass Transfer, vol. 45, no. 16, pp. 3383-3396, 2002.
J. C. Han, Y. Zhang, and C. Lee, "Augmented heat transfer in square channels with parallel, crossed, and V-shaped angled ribs," ASME Journal of Heat Transfer, vol. 113, no. 3, pp. 590-596, 1991.
B. Wang, W. Q. Tao, Q. W. Wang, and T. T. Wong, "Experimental study of developing turbulent flow and heat transfer in ribbed convergent/divergent square ducts," International Journal of Heat and Fluid Flow, vol. 22, no. 6, pp. 603-613, 2001.
M. S. Lee, S. S. Jeong, S. W. Ahn, and J. C. Han, "Effects of angled ribs on turbulent heat transfer and friction factors in a rectangular divergent channel," International Journal of Thermal Sciences, vol. 84, pp. 1-8, 2014.
M. S. Lee and S. W. Ahn, "Effects of rib angles on heat transfer in a divergent square channel with ribs on one wall," Journal of the Korean Society of Marine Engineering, vol. 39, no. 6, pp. 609-613, 2015.
S. J. Kline and F. A. McClintock, "Describing uncertainty in single sample experiments," Mechanical Engineering, vol. 75, pp. 3-8, 1953.
F. W. Dittus and L. M. K. Boelter, "Heat transfer in automobile radiators of the tubular type," University of California (Berkeley), Publication of Engineering, vol. 2, p. 443, 1930.
M. S. Lee, S. S. Jeong, S. W. Ahn, and J. C. Han, "Turbulent heat transfer and friction in rectangular convergent/divergent channels with ribs," AIAA Journal of Thermophysics and Heat Transfer, vol. 27, no. 4, pp. 660-667, 2013.
F. P. Incorpera and D. P. Dewitt, Fundamental of Heat and Mass Transfe", 4th ed., John Willy and Sons, Inc., p. 424, 1996.