0
Research Papers

Numerical Investigation of Heat Transfer Enhancement Using Hybrid Vortex Generator Arrays in Fin-and-Tube Heat Exchangers

[+] Author and Article Information
Shubham Agarwal

Department of Mechanical Engineering,
Birla Institute of Technology,
Mesra,
Ranchi 835215, India
e-mail: Shubham10507.12@bitmesra.ac.in

R. P. Sharma

Professor
Department of Mechanical Engineering,
Birla Institute of Technology,
Mesra,
Ranchi 835215, India

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS. Manuscript received October 22, 2015; final manuscript received February 28, 2016; published online April 19, 2016. Assoc. Editor: Amir Jokar.

J. Thermal Sci. Eng. Appl 8(3), 031007 (Apr 19, 2016) (9 pages) Paper No: TSEA-15-1302; doi: 10.1115/1.4033213 History: Received October 22, 2015; Revised February 28, 2016

This is a novel study for assessing the heat transfer enhancement in a multi-row inline-tube heat exchanger using hybrid vortex generator (VG) arrays, i.e., rectangular winglet pairs (RWPs) with different geometrical configurations installed in coherence for enhanced heat transfer. The three-dimensional numerical study uses a full scale seven-tube inline heat exchanger model. The effect of roll of rectangular winglet VG on heat transfer enhancement is analyzed and optimized roll angle is determined for maximum heat transfer enhancement. Four different configurations are analyzed and compared in this regard: (a) single RWP (no roll); (b) 3RWP-inline array(alternating tube row with no roll of VGs); (c) single RWP (with optimized roll angle VGs); and (d) 3RWP-inline array(alternating tube row with all VGs having optimized roll angle). It was found that the inward roll of VGs increased the heat transfer from the immediately downstream tube but reduced heat transfer enhancement capability of other VG pairs downstream. Further, four different hybrid configurations of VGs were analyzed and the optimum configuration was obtained. For the optimized hybrid configuration at Re = 670, RWP with optimized roll angle increased heat transfer by 17.5% from the tube it was installed on and by 42% from the immediately downstream tube. Increase in j/ƒ of 36.7% is obtained by use of hybrid VGs in the optimized hybrid configuration. The deductions from the current study are supposed to well enhance the performance of heat exchangers with different design configurations.

FIGURES IN THIS ARTICLE
<>
Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Taylor, H. D. , 1947, “ The Elimination of Diffuser Separation by Vortex Generators,” United Aircraft Corporation Report No. R-4012-3.
Gad-el-Hak, M. , and Brushnell, D. , 1991, “ Separation Control: Review,” ASME J. Fluids Eng., 113(1), pp. 5–30. [CrossRef]
Kuya, Y. , Takeda, K. , Zhang, X. , Beeton, S. , and Pandaleon, T. , 2009, “ Flow Separation Control on a Racecar Wing With Vortex Generators,” ASME J. Fluids Eng., 131(12), p. 121103. [CrossRef]
Aoki, K. , Muto, K. , and Okanaga, H. , 2010, “ Aerodynamic Characteristics and Flow Pattern of a Golf Ball With Rotation,” Procedia Eng., 2(2), pp. 2431–2436. [CrossRef]
Schubauer, G. B. , and Spangenberg, W. G. , 1960, “ Forced Mixing in Boundary Layers,” J. Fluid Mech., 8(01), pp. 10–12. [CrossRef]
Jacobi, A. M. , and Shah, R. K. , 1995, “ Heat Transfer Surface Enhancement Through the Use of Longitudinal Vortices: A Review of Recent Progress,” Exp. Therm. Fluid Sci., 11(3), pp. 295–309. [CrossRef]
Fiebig, M. , Valencia, A. , and Mitra, N. , 1993, “ Wing-Type Vortex Generators for Fin-and-Tube Heat Exchangers,” Exp. Therm. Fluid Sci., 7(4), pp. 287–295. [CrossRef]
Joardar, A. , and Jacobi, A. M. , 2008, “ Heat Transfer Enhancement by Winglet-Type Vortex Generator Arrays in Compact Plain-Fin-and-Tube Heat Exchangers,” Int. J. Refrig., 31(1), pp. 87–97. [CrossRef]
Biswas, G. , Torii, K. , Fujji, D. , and Nishino, K. , 1996, “ Numerical and Experimental Determination of Flow Structure and Heat Transfer Effects of Longitudinal Vortices in a Channel Flow,” Int. J. Heat Mass Transfer, 39(16), pp. 3441–3451. [CrossRef]
Russell, C. M. B. , Jones, T. V. , and Lee, G. H. , 1986, “ Heat Transfer Enhancement Using Vortex Generators,” Eighth International Heat Transfer Conference, Vol. 6, pp. 2909–2913.
Turk, A. Y. , and Junkhan, G. H. , 1986, “ Heat Transfer Enhancement Downstream of Vortex Generators on a Flat Plate,” Eighth International Heat Transfer Conference, Vol. 6, pp. 2903–2908.
Fiebig, M. , Kallweit, P. , Mitra, N. , and Tiggelbeck, S. , 1991, “ Heat Transfer Enhancement and Drag by Longitudinal Vortex Generators in Channel Flow,” Exp. Therm. Fluid Sci., 4(1), pp. 103–114. [CrossRef]
Fiebig, M. , 1995, “ Embedded Vortices in Internal Flow. Heat Transfer and Pressure Loss Enhancement,” Int. J. Heat Fluid Flow, 16(5), pp. 376–388. [CrossRef]
Biswas, G. , Mitra, N. K. , and Feibig, M. , 1994, “ Heat Transfer Enhancement in Fin-Tube Exchangers by Winglet Type Vortex Generators,” Int. J. Heat Mass Transfer, 37(2), pp. 283–291. [CrossRef]
Deb, P. , and Biswas, G. , 1995, “ Heat Transfer and Flow Structure in Laminar and Turbulent Flows in a Rectangular Channel With Longitudinal Vortices,” Int. J. Heat Mass Transfer, 38(13), pp. 2427–2444. [CrossRef]
Fiebig, M. , Grosse-Gorgemann, A. , and Mitra, N. K. , 1995, “ Conjugate Heat Transfer of a Finned Tube Part A: Heat Transfer Behaviour and Occurrence of Heat Transfer Reversal,” Numer. Heat Transfer, Part A, 28(2), pp. 133–146. [CrossRef]
Fiebig, M. , Chen, Y. , Grosse-Gorgemann, A. , and Mitra, N. K. , 1995, “ Conjugate Heat Transfer of a Finned Tube Part B: Heat Transfer Augmentation and Avoidance of Heat Transfer Reversal by Longitudinal Vortex Generators,” Numer. Heat Transfer, Part A, 28(2), pp. 147–155. [CrossRef]
Tutar, M. , and Akkoca, A. , 2004, “ Numerical Analysis of Fluid Flow and Heat Transfer Characteristics in Three Dimensional Plate Fin-and-Tube Heat Exchangers,” Numer. Heat Transfer, Part A, 46(3), pp. 301–321. [CrossRef]
Joardar, A. , and Jacobi, A. M. , 2007, “ A Numerical Study of Flow and Heat Transfer Enhancement Using an Array of Delta-Winglet Vortex Generators in Fin-and-Tube Heat Exchanger,” ASME J. Heat Transfer, 129(9), pp. 1156–1167. [CrossRef]
Wu, J. M. , and Tao, W. Q. , 2012, “ Effect of Longitudinal Vortex Generator on Heat Transfer in Rectangular Channels,” Appl. Therm. Eng., 37, pp. 67–72. [CrossRef]
Chu, P. , He, Y. L. , and Tao, W. Q. , 2009, “ Three-Dimensional Numerical Study of Flow and Heat Transfer Enhancement Using Vortex Generators in Fin-and-Tube Heat Exchangers,” ASME J. Heat Transfer, 131(9), p. 091903. [CrossRef]
He, Y.-L. , Chu, P. , Tao, W. Q. , Zhang, Y. , and Tao, X. , 2012, “ Analysis of Heat Transfer and Pressure Drop for Fin-and-Tube Heat Exchangers With Rectangular Winglet Type Vortex Generators,” Appl. Therm. Eng., 61, pp. 770–783. [CrossRef]
Salviano, L. O. , Dezan, D. J. , and Yanagihara, J. I. , 2015, “ Optimization of Winglet-Type Vortex Generator Positions and Angles in Plate-Fin Compact Heat Exchanger: Response Surface Methodology and Direct Optimization,” Int. J. Heat Mass Transfer, 82, pp. 373–387. [CrossRef]
Ferrouillat, S. , Tochon, P. , Garnier, C. , and Peerhossaini, H. , 2006, “ Intensification of Heat-Transfer and Mixing in Multifunctional Heat Exchangers by Artificially Generated Streamwise Vorticity,” Appl. Therm. Eng., 26(16), pp. 1820–1829. [CrossRef]
Torii, K. , Kwak, K. , and Nishino, K. , 2002, “ Heat Transfer Enhancement Accompanying Pressure-Loss Reduction With Winglet-Type Vortex Generators for Fin-and-Tube Heat Exchanger,” Int. J. Heat Mass Transfer, 45(18), pp. 3795–3801. [CrossRef]

Figures

Grahic Jump Location
Fig. 2

(a) Computational domain with 1RWP at leading tube, (b) and (c) VG placement with respect to the tube, and (d) effect of roll angle on VG orientation

Grahic Jump Location
Fig. 1

Schematic of core region of seven-tube inline heat exchanger model with 3RWPs

Grahic Jump Location
Fig. 3

Numerical and experimental comparison of (a) pressure drop and (b) overall heat transfer coefficient

Grahic Jump Location
Fig. 4

Baseline and RWP enhanced configurations (with and without roll): (a) baseline, (b) 1RWP pair leading edge, and (c) 3RWP on alternate tube

Grahic Jump Location
Fig. 6

Area-averaged total tube surface heat flux for baseline and VG enhanced configurations with and without VG roll at inlet face velocity of 1.4 ms−1

Grahic Jump Location
Fig. 10

Local temperature distributions on midplane for (a) baseline, (b) 3RWP (without roll), and (c) 3RWP (with roll) configurations

Grahic Jump Location
Fig. 7

Pressure drop across the heat exchanger in baseline and VG enhanced configurations

Grahic Jump Location
Fig. 8

Numerically generated pathlines for winglet enhanced configurations: (a) 3RWP (without roll), (b) 3RWP (with roll), and (c) zoom in view to visualize the flow swirl

Grahic Jump Location
Fig. 9

Local velocity distributions on midplane for (a) 3RWP (without roll) and (b) 3RWP (with roll) configurations

Grahic Jump Location
Fig. 5

Area-averaged heat flux with varying VG roll angle for (a) tube1 and (b) tube2

Grahic Jump Location
Fig. 11

Various hybrid configurations with ORWP and BRWP pairs

Grahic Jump Location
Fig. 14

(a) Variation in overall heat transfer coefficient in various configurations versus Re and (b) overall performance j/ƒ versus Re

Grahic Jump Location
Fig. 12

Area-averaged tube surface heat flux in hybrid and baseline configurations

Grahic Jump Location
Fig. 13

Span-averaged tube surface heat flux along tube circumference in baseline and VG enhanced configurations

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In