LES and RANS Studies of Oscillating Flows over Flat Plate
Publication: Journal of Engineering Mechanics
Volume 126, Issue 2
Abstract
Oscillatory flows over a flat plate are studied by using Large Eddy Simulation (LES) and Reynolds-Average Navier-Stokes (RANS) methods. A dynamic subgrid scale (SGS) model is employed in LES, while the Saffman's turbulence model in RANS. The mean velocity profile, the turbulence intensity, and the wall shear stress are computed and compared with earlier experimental and numerical works. The results indicate that the flow behaviors are quite different during the accelerating and decelerating phases of the oscillating cycle. The transition from laminar to turbulent is also investigated as a function of the Reynolds number, R, which represents the square of the ratio of the oscillation amplitude at free stream to the thickness of the Stokes layer at the plate. The present results both from LES and RANS show that the transition occurs in the range of 5 × 104 < R < 5 × 105. The evolution of the flow structure in the Stokes layer during the transition from laminar to turbulent is clearly demonstrated from the numerical results. The friction coefficient of the amplitude of oscillatory surface shear stress varies as R−0.5 with a phase angle of 45° in laminar regime and transition to R−0.23 with a phase angle of about 10° in turbulence regime. These variations in the surface shear stress with the Reynolds number are in excellent agreement with the earlier experimental results of Kamphuis and the numerical results of Blondeaux. The excellent agreement between the LES and RANS demonstrated that Saffman's turbulence model, as originally intended by Saffman, is applicable for unsteady flows.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Blondeaux, P. (1987). “Turbulent boundary layer at the bottom of gravity waves.” J. Hydro. Res., 25, 447–461.
2.
Eckelmann, H. (1974). “The structure of the viscous sublayer and the adjacent wall region in a turbulent channel flow.” J. Fluid Mech., Cambridge, U.K., 65, 439.
3.
Galperin, B., and Orszag, S. A. (1993). Large eddy simulation of complex engineering and geophysical flows. Cambridge University Press, Cambridge, U.K.
4.
Germano, M., Piomelli, U., Moin, P., and Cabot, W. H. (1991). “A dynamic subgrid-scale eddy viscosity model.” Phys. Fluids, 3, 1760–1765.
5.
Hino, M., Kashiwayanagi, M., Nakayama, A., and Hara, T. (1983). “Experiments on the turbulence statistics and the structure of a reciprocating oscillatory flow.” J. Fluid Mech., Cambridge, U.K., 131, 363–400.
6.
Jacobs, S. J. (1984). “Mass transport in a turbulent boundary layer under a progressive water wave.” J. Fluid Mech., Cambridge, U.K., 146, 303–312.
7.
Kamphuis, J. W. (1975). “Friction factor under oscillatory waves.”J. Wtrwy., Harb. and Coast. Engrg. Div., ASCE, 101, 135.
8.
Kim, J., Moin, P., and Moser, R. (1987). “Turbulence statistics in fully developed channel flow at low Reynolds number.” J. Fluid Mech., Cambridge, U.K., 177, 133–166.
9.
Kleiser, L., and Zang, T. A. (1991). “Numerical simulation of transition in wall-bounded shear flows.” Ann. Rev. Fluid Mech., 23, 495–537.
10.
Kreplin, H., and Eckelmann, H. (1979). “Behavior of the three fluctuating velocity components in the wall region of a turbulent channel flow.” Phys. Fluids, 22, 1233.
11.
Liu, P. L.-F., Davis, M. H., and Downing S. (1996). “Wave-induced boundary layer flows above and in a permeable bed.” J. Fluid Mech., Cambridge, U.K., 325, 195–218.
12.
Lu, X. Y., Dalton, C., and Zhang, J. (1997). “Application of large eddy simulation to an oscillating flow past a circular cylinder.” J. Fluids Engrg., 119, 519–525.
13.
Perng, C.-Y., and Street, R. L. (1989). “Three-dimensional unsteady flow simulations: alternative strategies for a volume-averaged calculation.” Int. J. Numer. Methods Fluids, 9, 341–362.
14.
Piomelli, U., and Zang, T. A. (1991). “Large-eddy simulation of transitional channel flow.” Comp. Phys. Comm., 65, 224–230.
15.
Saffman, P. G. (1970). “A model for inhomogeneous turbulent flow.” Proc. Roy. Soc. London A, 317, 417–433.
16.
Saffman, P. G., and Wilcox, P. C. (1974). “Turbulence model predictions for turbulent boundary layers.” AIAA J., 12, 541–546.
17.
Sato, S., Shimosako, K., and Watanabe, A. (1987). “Measurements of oscillatory turbulent boundary layer flow above ripples with a laser-Doppler velocimeter.” Coast. Engrg. in Japan, Tokyo, 30, 89–98.
18.
Smagorinsky, J. (1963). “General circulation experiments with the primitive equations, I. The basic experiment.” Mon. Weather Rev., 91, 99–164.
19.
Yuan, L. L., Street, R. L., and Ferziger, J. H. (1999). “Large eddy simulations of a round jet in a crossflow.” J. Fluid Mech., Cambridge, U.K., 379, 71–104.
20.
Zang, Y., Street, R. L., and Koseff, J. R. (1993). “A dynamic mixed subgrid-scale model and its application to turbulent recirculating flows.” Phys. Fluids, 5, 3186–3196.
21.
Zang, Y., Street, R. L., and Koseff, J. R. (1994). “A non-staggered grid, fractional step method for time-dependent imcompressible Navier-Stokes equations in curvilinear coordinates.” J. Comp. Phys., 114, 18–33.
Information & Authors
Information
Published In
History
Received: Nov 3, 1998
Published online: Feb 1, 2000
Published in print: Feb 2000
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.