Commenced in January 2007
Paper Count: 30309
A Computational Study of Very High Turbulent Flow and Heat Transfer Characteristics in Circular Duct with Hemispherical Inline Baffles
Abstract:This paper presents a computational study of steady state three dimensional very high turbulent flow and heat transfer characteristics in a constant temperature-surfaced circular duct fitted with 900 hemispherical inline baffles. The computations are based on realizable k-ɛ model with standard wall function considering the finite volume method, and the SIMPLE algorithm has been implemented. Computational Study are carried out for Reynolds number, Re ranging from 80000 to 120000, Prandtl Number, Pr of 0.73, Pitch Ratios, PR of 1,2,3,4,5 based on the hydraulic diameter of the channel, hydrodynamic entry length, thermal entry length and the test section. Ansys Fluent 15.0 software has been used to solve the flow field. Study reveals that circular pipe having baffles has a higher Nusselt number and friction factor compared to the smooth circular pipe without baffles. Maximum Nusselt number and friction factor are obtained for the PR=5 and PR=1 respectively. Nusselt number increases while pitch ratio increases in the range of study; however, friction factor also decreases up to PR 3 and after which it becomes almost constant up to PR 5. Thermal enhancement factor increases with increasing pitch ratio but with slightly decreasing Reynolds number in the range of study and becomes almost constant at higher Reynolds number. The computational results reveal that optimum thermal enhancement factor of 900 inline hemispherical baffle is about 1.23 for pitch ratio 5 at Reynolds number 120000.It also shows that the optimum pitch ratio for which the baffles can be installed in such very high turbulent flows should be 5. Results show that pitch ratio and Reynolds number play an important role on both fluid flow and heat transfer characteristics.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1107327Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1785
 Cengel, Y. A., Ghajar, A. J., Heat and Mass Transfer Fundamentals and Applications, McGraw Hill, New York, USA, 2011.
 Al-Arabi, M., Turbulent Heat Transfer in the Entrance Region of a Tube, Heat Transfer Engineering, 3 (1982), 3-4, pp. 76-83.
 El-Sayed, S. A., et al., Experimental Study of Turbulent Flow Inside a Circular Tube with Longitudinal Interrupted Fins in the Streamwise Direction, Experimental Thermal and Fluid Science, 15 (1997), 1, pp. 1- 15.
 Akansu, S. O., Heat Transfers and Pressure Drops for Porous-Ring Turbulators in a Circular Pipe, Applied Energy, 83 (2006), 3, pp. 280- 298.
 Tijing, L. D., et al., A Study on Heat Transfer Enhancement Using Straight and Twisted Internal Fin Inserts, International Communications in Heat and Mass Transfer, 33 (2006), 1, pp. 719-726.
 Nieckele, A. O., Saboya, F. E. M., Turbulent Heat Transfer and Pressure Drop in Pinned Annular Regions, Journal of the Brazilian Society of Mechanical Sciences, 22 (2000), 1, pp. 119-132.
 Yucel, N., Dinler, N., Numerical Study of Laminar and Turbulent Flow Through a Pipe with Fins Attached, Numerical Heat Transfer Part A, 49 (2006), 2, pp. 195-214.
 Dinler, N., Yucel, N., Flow and Heat Transfer in a Pipe with a Fin Attached to Inner Wall, Heat and Mass Transfer, 43 (2007), 8, pp. 817- 825.
 Abraham, J. P., Sparrow, E. M., Tong, J. C. K., Heat Transfer in all Pipe Flow Regimes: Laminar, Transitional/Intermittent, and Turbulent, International Journal of Heat and Mass Transfer, 52 (2009), 3-4, pp. 557-563.
 Raj, R. T. K., Ganne, S., Shell Side Numerical Analysis of a Shell and Tube Heat Exchanger Considering the Effects of Baffle Inclination on Fluid Flow, Thermal Science, 16 (2012), 4, pp. 1165-1174.
 Selvanaj, P., Sarangan, J., Suresh, S., Computational Fluid Dynamics Analysis on Heat Transfer and Friction Factor Characteristics of a Turbulent Flow for Internally Grooved Tubes, Thermal Science, 17 (2013), 4, pp. 1125-1137.
 Oguz Turgut, Erkan Kizilirmak, Effects of Reynolds number, Baffle Angle, and Baffle Distance on Three-dimensional Turbulent Flow and Heat Transfer in a Circular Pipe, Thermal Science (2014), pp. 01-20.
 P.Promovonge, S.Sripattanipipat, Numerical Analysis of Laminar Flow Heat Transfer in Square Duct with V-Shaped Baffles, Chiang Mai University International Conference, vol 1, (2011), No 1, pp. 83-92.
 P,Promovonge,S. Tamna,M. Pimsarn,C. Thianpong, Thermal Characterization in a Circular Tube Fitted with Inclined Horseshoe Baffles, Applied Thermal Engineering, 75 (2015),pp. 1147-1155.