THERMAL SCIENCE

International Scientific Journal

TURBULENCE AND PRESSURE DROP BEHAVIORS AROUND SEMICIRCULAR RIBS IN A RECTANGULAR CHANNEL

ABSTRACT
The article represents an experimental investigation on friction and turbulent flow characteristics of free airflow through a rectangular duct fitted with semicircular ribs of uniform height (e = 3.5 mm) on one principle wall. The aspect ratio of the rectangular duct was AR= 5 where the duct height (H) was 30 mm. Four different rib pitches (P) of 28 mm, 35 mm, 42 mm and 49 mm were examined with constant rib height to hydraulic diameter ratio (e/Dh = 0.07) and constant rib height to channel height ratio (e/H = 0.116). The experimental results show some significant effects of pressure drop as well as turbulent characteristics at various configurations among different numbers of rib arrangements varying Reynolds number in the range of 15000 to 30000. Experimental results have been compared with numerical analysis and it can be seen a good agreement. The result explains the phenomena elaborately between two periodic ribs and enables to optimize the rib pitch ratio in terms of turbulence kinetic energy for maximum heat transfer. [This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (No. 2012-0004544)]
KEYWORDS
PAPER SUBMITTED: 2011-10-22
PAPER REVISED: 2012-07-01
PAPER ACCEPTED: 2012-07-11
DOI REFERENCE: https://doi.org/10.2298/TSCI111022142N
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2014, VOLUME 18, ISSUE Issue 2, PAGES [419 - 430]
REFERENCES
  1. Webb, R. L., Eckert, E. R. G., and Goldstein. R. J., Heat Transfer and Friction in Tubes with Repeated-Rib Roughness, International Journal of Heat and Mass Transfer, 14 (1971) , pp. 601-617
  2. Hanjalic, K., Launder, B.E., Fully Developed Asymmetric Flow in a Plane Chanel, Journal of Fluid Mechanics, 51(1972), pp. 301- 335
  3. G. Tanda, Heat transfer in rectangular channels transverse and V-shaped broken ribs, International Journal of Heat and Mass Transfer, 47(2004) , pp. 229-243
  4. J. C. Han, Y. M. Zhang, High performance heat transfer duct with parallel and V-shaped broken rib, International Journal of heat and mass transfer, 35 (1992), pp. 513-523
  5. P.R. Chandra, C.R. Alexander, J.C. Han, Heat transfer and friction behavior in rectangular channel with varying number of ribbed walls, International Journal of Heat and Mass Transfer, 46 (2003) , pp. 481-495
  6. M. Huh, Y.H. Liu, J.C. Han, S. Chopra, Effect of Rib Spacing on Heat Transfer in a Two-pass Rectangular Channel (AR = 1:4) with a Sharp Entrance at High Rotation Numbers, ASME Paper no. GT2008-50311, 2008
  7. Khudheyer S. MUSHATET, Simulation of turbulent flow and heat transfer over a backward -facing step with ribs turbulators, Thermal Science, 15 (2011), 1, pp. 245-255
  8. Hwang, J. J., Heat transfer-friction characteristic comparison in rectangular ducts with slit and solid ribs mounted on the wall, ASME J. Heat Transfer, 120 (1998), 3, Pp. 709-716
  9. Wilcox, D. C., Turbulent modeling for CFD, DCW Inc, 1993
  10. Menter, F. R., Zonal two-equation k-ω turbulence model for aerodynamic flow, AIAA Paper, pp. 1993-2906, 1993
  11. Durbin, P. A., A Reynolds stress model for near-wall turbulence, J. Fluid Mechanics, 249 (1993), pp. 456-498,
  12. Vukman BAKI, Martin SCHMID and Branislav STANKOVI, Experimental investigation of turbulent structures of flow around a sphere, Thermal Science, 10 (2006), 2, pp. 97-112
  13. Fluent 6.3 user's guide. Fluent Inc; 2003.
  14. Frank P. Incropera, David P. DeWitt, Introduction to Heat Transfer, Second Edition, Page no. 408
  15. Kline, S. J. and McClintock, F. A., Describing Uncertainties on Single Sample Experiments, Mechanical Engineering, 57 (1953)

© 2022 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence