Performance Evaluation of Vortex Generator of Finite Thickness to Augment Heat Transfer in a Compact Heat Exchanger

Bhupender Sharma, Dr. Gulshan Sachdeva, Dr. Gian Bhushan


The effect of non dimensional thickness of a winglet type vortex generator is investigated in terms of heat transfer rate, stream-wise vortices and flow losses in a plate fin heat exchanger with triangular inserts as secondary fins. The winglet type vortex generators are mounted alternatively on the upper and lower plates of the heat exchanger to disrupt the flow in the triangular domain formed by the inserts. The fluid flow within the duct is considered to be confined and laminar. While the hydrodynamic flow is fully developed, the thermal characteristics are assumed to be in developing stage under isothermal boundary conditions. The winglet is located in the duct where the flow is fully developed (Xi = 2.765 w.r.t. leading edge) at an angle of 27o with respect to the bulk flow direction. The aforesaid performance characteristics are computed numerically by solving the mass continuity, momentum and energy equations. Computational results clearly show an enhancement of 12.91% in the heat transfer rate (quantified as Num/ Nuo) for an increase in non dimensional thickness c/2H from 0.00 to 0.05. Besides, the pressure drop penalty is found to be only 3.8% at Re = 150. The results have also been substantiated by carrying out experiments on a scaled model configuration. Three dimensional velocity components are verified behind the winglet to ensure the stable flow field for non dimensional thickness of winglet c/2H=0.05 and Reynolds number of 350.

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Biswas et al., (1996). Numerical and Experimental Determination of Flow Structure and Heat Transfer Effects of Longitudinal Vortices in a Channel flow. International Journal of Heat and Mass Transfer, 39, pp. 3441–3451.

Brockmeier, U., Guentermann, T .H., Fiebig, M., (1993) Performance Evaluation of a Vortex Generator Heat Transfer Surface and Comparison with Different High Performance Surfaces, International Journal of Heat Mass Transfer, Vol-36, pp. 2575-2586.

Deb, P., Biswas, G., Mitra, N.K., (1995). Heat Transfer and Flow Structure in Laminar and Turbulent Flows in a Rectangular Channel with Longitudinal Vortices. International Journal of Heat Mass Transfer, 38, pp. 2427-2444.

Fiebig, M. & Mitra, N.K., (1998). Experimental and Numerical Investigation of Heat Transfer Enhancement with Wing-type Vortex Generators. International series on Development in Heat Transfer; Computer simulations in Compact Heat Exchangers, Computational Mechanics Publication, USA, 1, pp. 227-254.

Gupta, M., Kasana, K.S., Vasudevan, R., (2009). Numerical Study of Effect on Flow Structure and Heat Transfer with a Rectangular Winglet Pair in a Plate-Fin Heat Exchanger. Journal of Mechanical Engineering Science, I MechE U.K., 223, pp. 2109-2115.

Harlow, F. H. and Welch, J. E., (1965). Numerical Calculation of Time-Dependent Viscous Incompressible Flow of Fluid with Free Surfaces. The Physics of Fluids, 8, pp. 2182-2188.

Hiravennavar, S.R., Tulapurkara, E.G., Biswas, G. A., (2007). Note on the Flow and Heat Transfer Enhancement in a Channel with Built-in Winglet Pair. International Journal of Heat and Fluid Flow, 28, pp. 299–305.

Hirt, C. W., Nichols, B. D., Romero, N. C., (1975). SOLA—A Numerical Solution Algorithm for Transient Fluid Flows, Los Alamos Scientific Lab Report LA, pp.5652.

Orlanski, I., (1976) A Simple Boundary Condition for Unbounded Flows. Journal of Computational Physics, 21, pp. 251-269,241.

Kataoka, K., et al., (1977). Heat/Mass Transfer in Taylor Vortex Flow with Constant Axial Flow Rates. International Journals of Heat Mass Transfer, 20, pp. 57-63.

Pesteei et al., (2005). Experimental Study of the Effect of Winglet Location on Heat Transfer Enhancement and Pressure Drop in Fin-Tube Heat Exchangers. International Journals of Applied Thermal Engineering, 25, pp. 1684–1696.

Sachdeva, G., Vasudevan, R., Kasana, K. S., (2010). Computation of Heat Transfer Enhancement in a Plate- Fin Heat exchanger with Triangular Inserts and Delta Wing Vortex Generator. International Journal for Numerical Methods in Fluids, 63, pp. 1031–1047.

Sohankar, A., Davidson, L., (2003). Numerical Study of Heat and Fluid Flow in a Plate-Fin Heat Exchanger with Vortex Generators. Turbulence Heat and Mass Transfer, 4, pp. 1155–1162.

Tigglebeck et al., (1992). Flow Structure and Heat Transfer in a Channel with Multiple Longitudinal Vortex Generator. Experiment Thermal and Fluid Science, 5, pp. 425-436.

Torri et al., (1989). The Effects of Longitudinal Vortices on Heat Transfer of Laminar Boundary. International Journal Series-II JSME, 32, pp.359-402.

Turk, A.Y., Junkhan, G.H., (1986). Heat Transfer Enhancement Downstream of Vortex Generators on a Flat Plate. Proceedings of the Eighth International Heat Transfer Conference, 6, pp. 2903–2908.

Vasudevan, R., Eswaran, V. and Biswas, G., (2000). Winglet-type Vortex Generators for Plate Fin Heat Exchangers using Triangular Fins (Part-A). Numerical Heat Transfer, An International Journal of Computation and Methodology, 58, pp. 533-555.

Yang, J. S., Seo, J. K., Lee, K. B., (2001). A Numerical Analysis on Flow Field and Heat Transfer by Interaction between a Pair of Vortices in Rectangular Channel Flow. Current Applied Physics, 1, pp. 393-405.

Yang, J. S., Lee, D. W., Choi, G. M., (2008). Numerical Investigation of Fluid Flow and Heat Transfer Characteristics by Common Flow Up. International Journal of Heat and Mass Transfer, 51, pp. 6332-6336.

Yanagihara, J.I., Torii, K., (1993). Heat Transfer Augmentation by Longitudinal Vortices Rows. Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, 1, pp. 560–567.

Zhang, L. Z., (2007). Laminar Flow and Heat Transfer in Plate-Fin Triangular Ducts in Thermally Developing Entry Region. International Journal of Heat Mass Transfer, 50, pp. 1637-1640.

Zhu, J. X., Mitra, N. K., Fiebig, M., (1993). Effects of Longitudinal Vortex Generators of Heat Transfer and Flow Loss in Turbulent Channel Flows. International Journal of Heat Mass Transfer, 36, pp. 2339-2347.

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