Abstract
The Complex turbulent water flow in a strongly curved turn-around duct has been studied. The turn-around duct had an aspect ratio of 10∶1 and the ratio of the channel height to the mean radius was 1.0. Extensive measurements throughout the curved duct including wall static pressures and mean velocities were made using Laser Doppler Velocimeter for a Reynolds number of 210,000 based on the height of the channel and the average velocity. Analytical calculations of the potential flow were made using Green’s function and the Rayleigh-Ritz method. Based on the turbulence mechanism and stability consideration, a simplified physical model for the outer layer near the start, of the turn along the inner convex wall was hypothesized. This physical model leads to a system of non-linear equations represented in orthogonal curvilinear coordinates. These equations were solved numerically using an iteration method. Comparison of the measured data with the calculated values reveals that the present flow shows the characteristics of an inertial dominated, developing curved flow. The outer layer in a quasi-laminar flow was governed by inviscid-rotational motion. The numerical solution for this region was verified by comparing the calculated and measured flow results. Near the turn exit along the inner wall, a large flow reversal was observed. Spanwise measurements showed that the present turn-around duct flow was approximately two-dimensional. The local mean velocity profiles in the turn for different flow rates were similar when normalized by the average velocity.
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References
Badrinarayanan, M. A. and Ramjee, A., 1969, “On the Criteria for Reverse Transition in a Two Dimensional Boundary Flow,”J. Fluid Mech., Vol. 35, p. 225.
Barlow, R. S. and Johnston, J. P., 1988, “Structure of Turbulent Boundary Layer on a Concave Surface,”J. Fluid Mech., Vol. 191, p. 137.
Clauser, F. H., 1956, “Turbulent Boundary Layer,”Advances in Applied Mechanics by H. L. Dryden, Vol. 4, Academic Press Inc.
Ellis, L. B. and Joubert, P. N., 1974, “Turbulent Shear Flow in a Curved Duct,”J. Fluid Mech., Vol. 62, p. 65.
Eskinazi, S. and Yeh, H., 1956, “An Investigation on Fully Developed Turbulent Flows in a Curved Channel,”J. Aero. Sci., Vol. 23, p. 23.
Gibson, M. M., Verriopoulos, C. A. and Vlachos, N. S., 1984, “Turbulent Boundary Layer on a Midly Curved Convex Surface,”Exp. in Fluids. Vol. 2, p. 17.
Gillis, J. C. and Johnston, J. P., 1983, “Turbulent Boundary Layer Flow and Structure on a Convex Wall and its Redevelopment on a Flat Wall,”J. Fluid Mech., Vol. 135, p. 123.
Hunt, I. A. and Joubert, P. N., 1979, “Effects of Small Streamline Curvature on Turbulent Duct Flow,”J. Fluid Mech., Vol. 91, p. 633.
Lau, J., 1966, “Recalculation of Incompressible Flow in Two-Dimensional Bends,”Canadian Aeronautics and Space Journal, Sep.
Launder, B. E., 1963, “The Turbulent Boundary Layer in a Strongly Negative Pressure Gradient,”M.I.T. Gas Turbine Lab. Rep. No. 71.
Meroney, R. N. and Bradshaw, P., 1975, “Turbulent Boundary Layer Growth over a Longitudinally Curved Surface,”AIAA J., Vol. 13, p. 1448.
Monson, D. J., Seegmiller, H. L. and McConnaughey, P. K., 1989, “Comprison of LDV Measurements and Navier-Stokes Solutions in a Two-Dimensional 180-Degree Turn-Around Duct,”27th Aerospace Sciences Meeting, Jan. 9–12, 1989/Reno, Nevada.
Muck, K. C., Hoffmann, P. H. and Bradshaw, P., 1985, “The Effect of Convex Surface Curvature on Turbulent Boundary Layers,”J. Fluid Mech., Vol. 161, p. 347.
Patankar, S. V., 1980,Numerical Heat Transfer and Fluid Flow, McGraw Hill Book Company, New York, NY.
Patel, V. C. and Head, M. R., 1968, “Reversion of Turbulent to Laminar Flow,”J. Fluid Mech., Vol. 34, p. 371.
Press, W. H., Flannery, B. P., Teukolsky, S. A. and Vettering, W. T., 1986,Numerical Recipes, Cambridge University Press, New York, New York.
Ramaprian, B. R. and Shivaprasad, B. G., 1978, “The Structure of Turbulent Boundary Layers Along Mildly Curved Surfaces,”J. Fluid Mech., Vol. 85, p. 273.
Rayleigh, J. W. S., 1917, “On the Dynamics of Revolving Fluids,”Pro. of the Roy. Soc. of London, Vol. 93, Serial A, p. 148.
So, R. M. C. and Mellor, G. L., 1972, “An Experimental Investigation of Turbulent Boundary Layers Along Curved Surfaces,”NASA CR-1940.
Wattendorf, F. L., 1935, “A Study of the Effect of Curvature on Fully Developed Turbulent Flow,”Pro. Roy. Soc., A 148, p. 565.
Wilcken, H., 1930, “Effect of Curved Surfaces on Turbulent Boundary Layers,”NASA TT-F-11421.
Yamaguchi, H., 1987, “Fundamental Studies on the Control of Turbulent Boundary Layers: Experimental Investigations of the Effect of Convex Curvature on Boundary Layer Characteristics,” Nippon Kikai Gakkai Ronbunshu, B-Hen, Vol. 53, N489, May, p. 1505–1510.
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Shin, JC. Experiments on the turbulent shear flow in a turn-around duct(I)—The mean flow characteristics. KSME Journal 8, 444–459 (1994). https://doi.org/10.1007/BF02944716
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DOI: https://doi.org/10.1007/BF02944716