A Computational Study of Very High Turbulent Flow and Heat Transfer Characteristics in Circular Duct with Hemispherical Inline Baffles
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.
[1] Cengel, Y. A., Ghajar, A. J., Heat and Mass Transfer Fundamentals and
Applications, McGraw Hill, New York, USA, 2011.
[2] Al-Arabi, M., Turbulent Heat Transfer in the Entrance Region of a Tube,
Heat Transfer Engineering, 3 (1982), 3-4, pp. 76-83.
[3] 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.
[4] Akansu, S. O., Heat Transfers and Pressure Drops for Porous-Ring
Turbulators in a Circular Pipe, Applied Energy, 83 (2006), 3, pp. 280-
298.
[5] 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.
[6] 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.
[7] 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.
[8] 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.
[9] 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.
[10] 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.
[11] 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.
[12] 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.
[13] 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.
[14] 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.
[1] Cengel, Y. A., Ghajar, A. J., Heat and Mass Transfer Fundamentals and
Applications, McGraw Hill, New York, USA, 2011.
[2] Al-Arabi, M., Turbulent Heat Transfer in the Entrance Region of a Tube,
Heat Transfer Engineering, 3 (1982), 3-4, pp. 76-83.
[3] 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.
[4] Akansu, S. O., Heat Transfers and Pressure Drops for Porous-Ring
Turbulators in a Circular Pipe, Applied Energy, 83 (2006), 3, pp. 280-
298.
[5] 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.
[6] 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.
[7] 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.
[8] 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.
[9] 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.
[10] 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.
[11] 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.
[12] 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.
[13] 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.
[14] 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.
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:70287", author = "Dipak Sen and Rajdeep Ghosh", title = "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.", keywords = "Friction factor, heat transfer, turbulent flow, circular
duct, baffle, pitch ratio.", volume = "9", number = "6", pages = "1046-6", }