年間 8 号発行
ISSN 印刷: 1065-5131
ISSN オンライン: 1563-5074
Indexed in
HEAT TRANSFER AND PRESSURE DROP CHARACTERISTICS FOR FLOW THROUGH SQUARE CHANNEL WITH DELTA WING VORTEX GENERATOR ELEMENTS ON TWO OPPOSITE WALLS
要約
Experimental results for friction factor and heat transfer coefficients for flow through a square duct with delta wing vortex generators on two opposite walls are reported. The effects of geometrical parameters such as pitch-to-height ratio, aspect ratio, and height-to-duct hydraulic diameter ratio on the heat transfer coefficient and pressure drop were studied. Comprehensive results for a single vortex generator and limited data for two vortex generators in the spanwise direction at a given axial location are presented. Detailed local heat transfer distributions are presented for selected configurations. High heat transfer coefficients were observed both underneath and between successive vortex generator elements. The magnitudes of average heat transfer coefficients on the smooth walls adjacent to the roughened walls were only about 10% lower than those for the roughened walls. The ratio of Nusselt number and friction factor with and without the delta wing vortex generators for constant Reynolds number conditions are presented. The Nusselt number ratios at constant pumping power condition are also reported; the highest values for a single and two vortex generators at an axial location were observed to be 2.8 and 3.1, respectively. Semi-empirical correlations for heat transfer and friction factor, developed on the basis of available methodologies for roughened ducts, predict the measured data to within an error of about 15%.
-
Akbari, M.M., Murata, A., Mochizuki, S., Saito, H, and lwamoto, K., Effects of Vortex Generator Arrangements on Heat Transfer Enhancement over a Two-Row Fin-and-Tube Heat Exchanger, J. Enhanced Heat Transf., vol. 16, no. 4, pp. 315-329,2009.
-
Bekele, A., Mishra, M., and Dutta, S., Heat Transfer Augmentation in Solar Air Heater using Delta Shaped Obstacles Mounted on the Absorber Plate, Int. J. Sustainable Energy, vol. 32, no. 1, pp. 53-69,2011.
-
Bekele, A., Mishra, M., and Dutta, S., Performance Characteristics of Solar Air Heater with Surface Mounted Obstacles, Energy Conversion Manag., vol. 85, pp. 603-611,2014.
-
Biswas, G. and Chattopadhyay, H., Heat Transfer in a Channel with in-Built Wing Type Vortex Generators, Int. J. Heat Mass Transf., vol. 35, no. 4, pp. 803-814,1992.
-
Biswas, G., Torii, K., Fuji, D., and Nishino, K., Numerical and Experimental Determination of Flow Structure and Heat Transfer Effects of Longitudinal Vortices in a Channel Flow, Int. J. Heat Mass Transf., vol. 39, no. 16, pp. 3441-3451,1996.
-
Caliskan, S., Experimental Investigation of Heat Transfer in a Channel Flow with New Winglet-Type Vortex Generators, Int. J. Heat Mass Transf., vol. 78, pp. 604-614,2014.
-
Chamoli, S., Lu, R., and Yu, P., Thermal Characteristic of Turbulent Flow through a Circular Tube Fitted with Perforated Vortex Generator Inserts, Appl. Thermal Eng., vol. 121, pp. 1117-1134,2017.
-
Edwards, F.J. and Alker, C.J.R., The Improvement of Forced Convection Surface Heat Transfer using Pro-trusions in the Form of Cubes and Vortex Generators, Proc. 5th Int. Heat Trans. Conf., JSME, Tokyo, vol. 2, no. 3, pp. 244-248,1974.
-
Eiamsa-Ard, S. and Promvonge, P., Influence of Double-Sided Delta-Wing Tape Insert with Alternate-Axes on Flow and Heat Transfer Characteristics in a Heat Exchanger Tube, Chinese J. Chem. Eng., vol. 19, no. 3, pp. 410-423,2011.
-
Fiebig, M., Brockmeier, U., Mitra, N.K., and Guntermann, T., Structure of Velocity and Temperature Fields in Laminar Channel Flows with Longitudinal VGs, Numer. Heat Trans., Part A, vol. 15, pp. 281-302, 1989.
-
Fiebig, M., Kallweit, P., and Mitra, N.K., Wing Type Vortex Generators for Heat Transfer Enhancement, Proc. 8th Int. Heat Trans. Conf., New York: Hemisphere, vol. 6, pp. 2909-2913,1986.
-
Fiebig, M., Kallweit, P., Mitra, N.K., and Tiggelbeck, S., Heat Transfer Enhancement and Drag by Longitudinal Vortex Generators in Channel Flow, Exp. Thermal Fluid Sci., vol. 4, pp. 103-114,1991.
-
Fiebig, M., Valencia, A., and Mitra, N.K., Wing-Type Vortex Generators for Fin-and-Tube Heat Exchangers, Exp. Thermal Fluid Scl, vol. 7, pp. 287-295,1993.
-
Gentry, M.C. and Jacobi, A.M., Heat Transfer Enhancement by Delta-Wing Generated Tip Vortices in Flat-Plate and Developing Channel Flows, ASME J. Heat Transf., vol. 124, pp. 1158-1168,2002.
-
Gentry, M.C. and Jacobi, A.M., Heat Transfer Enhancement by Delta-Wing Vortex Generators on a Flat Plate: Vortex Interactions with the Boundary Layer, Exp. Thermal Fluid Sci., vol. 14, pp. 231-242, 1997.
-
Gnielinski, V., New Equations for Heat Transfer and Mass Transfer in Turbulent Pipe and Channel Flow, Int. Chem. Eng., vol. 16, no. 2, pp. 359-368,1976.
-
Han, J.C. and Park, J.S., Developing Heat Transfer in Rectangular Channels with Rib Turbulator, Int. J. Heat Mass Transf., vol. 31, no. 1, pp. 183-195,1988.
-
Han, J.C., Heat Transfer and Friction in Channels with Two Opposite Rib-Roughened Walls, ASME J. Heat Transf., vol. 106, no. 4, pp. 774-781,1984.
-
Han, J.C., Huang, J. J., and Lee, C.P, Augmented Heat Transfer in Square Channels with Wedge-Shaped and Delta-Shaped Turbulence Promoters, J. Enhanced Heat Transf., vol. 1, no. 1, pp. 37-52,1994.
-
Hu, W., Su, M., Wang, L., Zhang, Q., Chang, L., Liu, S., and Wang, L., The Optimum Spacing of Circular Bank Fin Heat Exchanger with Vortex Generator, Heat Mass Transf., vol. 49, no. 9, pp. 1271-1285, 2013.
-
Jacobi, A.M. and Shah, R.K., Heat Transfer Surface Enhancement through the Use of Longitudinal Vortices: A Review of Recent Progress, Exp. Thermal Fluid Sci., vol. 11, pp. 295-303,1995.
-
Joardar, A. and Jacobi, A.M., Impact of Leading Edge Delta-Wing Vortex Generators on the Thermal Performance of a Flat Tube, Louvered-Fin Compact Heat Exchanger, Int. J. Heat Mass Transf., vol. 48, pp. 1480-1493,2005.
-
Lei, Y., Zheng, F., Song, C., and Lyu, Y., Improving the Thermal Hydraulic Performance of a Circular Tube using Punched Delta Winglet Vortex Generators, Int. J. Heat Mass Transf., vol. 111, pp. 299-311,2017.
-
Lemenand, T., Habchi, C., Valle, D.D., and Peerhossaini, H., Vorticity and Convective Heat Transfer Down¬stream of a Vortex Generator, Int. J. Thermal Sci., vol. 125, pp. 342-349,2018.
-
Liou, T., Chen, C., and Tsai, T., Heat Transfer and Fluid Flow in a Square Duct with 12 Different Shaped Vortex Generators, ASME J. Heat Transf., vol. 122, pp. 327-335,2000.
-
Nalawade, M., Heat Transfer Enhancement in Ducts with Delta Wing Vortex Generators, PhD thesis, Indian Institute of Technology Bombay, 2007.
-
Qi, C., Min, C., Xie, S., and Kong, X., Experimental Study of Fluid Flow and Heat Transfer in a Rectangular Channel with Novel Longitudinal Vortex Generators, J. Enhanced Heat Transf., vol. 17, no. 4, pp. 301— 311,2010.
-
Singh, P. and Ekkad, S., Experimental Study of Heat Transfer Augmentation in a Two Pass Channel Fea¬turing V-Ribs and Cylindrical Dimples, Appl. Thermal Eng., vol. 116, pp. 205-216,2017.
-
Skullong, S. and Promvonge, P., Experimental Investigation on Turbulent Convection in Solar Air Heater Channel Fitted with Delta Winglet Vortex Generator, Chinese J. Chem. Eng., vol. 22, no. 1, pp. 1-10, 2014.
-
Skullong, S., Promvonge, P., Jayranaiwachira, N., and Thianpong, C., Experimental and Numerical Heat Transfer in a Tubular Heat Exchanger with Delta Wing Inserts, Chem. Eng. Proc.: Proc. Intensif., vol. 109, pp. 164-177,2016.
-
Tang, L.H., Chu, W.X., Ahmed, N., and Zeng, M, A New Configuration of Winglet Vortex Generator to Enhance Heat Transfer in a Rectangular Channel, Appl. Thermal Eng., vol. 104, pp. 74-84,2016.
-
Tiggelbeck, S ., Mitra, N.K., and Fiebig, M., Experimental Investigations of Heat Transfer Enhancement and Flow Losses in a Channel with Double Rows of Longitudinal Vortex Generators, Int. J. Heat Mass Transf., vol. 36, no. 9, pp. 2327-2337,1993.
-
Tiggelbeck, S., Mitra, N.K., and Fiebig, M., Flow Structure and Heat Transfer in a Channel with Multiple Longitudinal Vortex Generators, Exp. Thermal Fluid Sci., vol. 5, pp. 425-436,1992.
-
Turk, A Y. and Junkhan, G.H., Heat Transfer Enhancement Downstream of Vortex Generators on a Flat Plate, Proc. 8th Int. Heat Trans. Conf., Hemisphere, New York, vol. 6, pp. 2903-2908,1986.
-
Wang, C.C., Lo, J., Lin, Y.T., and Wei, C.S., Flow Visualization of Annular and Delta Winglet Vortex Generators in Fin-and-Tube Heat Exchanger Application, Int. J. Heat Mass Transf., vol. 45, pp. 3803- 3815,2002a.
-
Wang, L.B., Zhang, Y.H., Su, Y.X., and Gao, S.D., Local and Average Heat/Mass Transfer over a Flat Tube Bank Fin Mounted In-Line Vortex Generators with Small Longitudinal Spacing, J. Enhanced Heat Transf., vol. 9, no. 2, pp. 77-87,2002b.
-
Webb, R.L. and Eckert, E.R.G., Application of Rough Surfaces to Heat Exchanger Design, Int. J. Heat Mass Transf., vol. 15, pp. 1647-1658,1972.
-
Wu, J.M. and Tao, W.Q., Effect of Longitudinal Vortex Generator on Heat Transfer in Rectangular Chan¬nels, Appl. Thermal Eng., vol. 37, pp. 67-72,2012.
-
Xu, Z., Han, Z., Wang, J., and Liu, Z., The Characteristics of Heat Transfer and Flow Resistance in a Rectangular Channel with Vortex Generators, Int. J. Heat Mass Transf., vol. 116, pp. 61-72,2018.
-
Zhu, J.X., Mitra, N.K., and Fiebig, M., Effects of Longitudinal Vortex Generators of Heat Transfer and Flow Loss in Turbulent Channel Flows, Int. J. Heat Mass Transf., vol. 36, no. 9, pp. 2339-2347,1993.