CHARACTERIZATION OF TRANSITION TO TURBULENCE IN SOLITARY WAVE BOUNDARY LAYER

Bambang Winarta, Hitoshi Tanaka, Hiroto Yamaji

Abstract


This paper reports on continues an experimental investigation of characterizing transition to turbulence for solitary wave boundary layer in a smooth bed condition. A series of experiments have been carried out by means of a closed conduit solitary wave generation system over the Reynolds number (Re) range 5.64 x 105 – 7.34 x 105. Additionally, the instantaneous velocities were measured by using a Laser Doppler Veloci-meter (LDV) over 50 wave numbers and at 17 to 22 points in the vertical direction. The turbulence intermittency has been analyzed based on experimental data. Moreover, momentum method has been employed for calculating bottom shear stress for all cases. And then, the turbulence intensity is plotted to give clearly description how turbulence generated in the various values of Re. The phase difference and wave friction factor obtained from the present experiment has an excellent agreement with the result of previous studies. Inconsistency critical Reynolds number (Recr) can be found in solitary wave case in terms of phase difference and wave friction factor, this observable fact is difference with sinusoidal wave case which has consistency in Recr.

Keywords


solitary wave; bottom boundary layer; transition to turbulence; turbulence intermittency; bottom shear stress; turbulence intensity; phase difference; wave friction factor

References


Blondeaux, P. and Vittori, G. 2012. RANS modeling of the turbulent boundary layer under a solitary wave. Coastal Eng., 60, 1-10.http://dx.doi.org/10.1016/j.coastaleng.2011.07.005

Ippen, A.T. and Kulin, G. 1957. The effects of boundary resistance on the solitary wave. La Houille Blance, 3, 390-407.http://dx.doi.org/10.1051/lhb/1957038

Jensen, B., Sumer, B.M. and Fredsøe, J. 1989. Turbulent oscillatory boundary layer at high Reynolds number. J. Fluid Mech., 206, 265-297http://dx.doi.org/10.1017/S0022112089002302

Keulegan, G. H. 1948. Gradual damping of solitary waves. U.S. Department of Commerce, National Bureau of Standards. RP1895, 40, 487-498.

Liu, P. L. -F., Simarro, G., Vandever, J. and Orfila, A. 2006. Experimental and numerical investigation of viscous effectcs on solitary wave propagatation in a wave tank. Coastal Eng., 53, 181-190.http://dx.doi.org/10.1016/j.coastaleng.2005.10.008

Liu, P. L. -F., Park, Y. S. and Cowen, E. A. 2007. Boundary layer flow and bed shear stress under a solitary wave. J. Fluid Mech., 574, 449-463.http://dx.doi.org/10.1017/S0022112006004253

Naheer, E. 1978. The damping of solitary waves. J. Hydraul. Res., 16 (3), 235-248.http://dx.doi.org/10.1080/00221687809499619

Sleath, J.F.A. 1987. Turbulent oscillatory flow over rough beds. J. Fluid Mech., 182, 369-409.http://dx.doi.org/10.1017/S0022112087002374

Sumer, B. M., Jensen, P. M., Sørensen, L. B., Fredsøe, J., Liu, P. L.-F. and Cartesen, S. 2010. Coherent structures in wave boundary layers. Part 2. Solitary motion. J. Fluid Mech., 646, 207-231.http://dx.doi.org/10.1017/S0022112009992837

Suntoyo., and Tanaka, H. 2009b. Numerical study on boundary layer flows under solitary wave, Journal of Hydro-Environ Res., 3(3), 129-137

Tanaka, H., Sumer, B. M. and Lodahl, C. 1998. Theoretical and experimental investigation on laminar boundary layers under cnoidal wave motion. Coastal Eng., 40(1), 81-98.http://dx.doi.org/10.1142/S0578563498000066

Tanaka, H., Bambang Winarta., Suntoyo and Yamaji, H. 2012. Validation of a new generation system for bottom boundary layer beneath solitary wave, Coastal Eng., 59, 46-56http://dx.doi.org/10.1016/j.coastaleng.2011.07.003

Vittori, G. and Blondeaux, P. 2008. Turbulent boundary layer under a solitary wave. J. Fluid Mech., 615, 433-443.http://dx.doi.org/10.1017/S0022112008003893

Vittori, G. and Blondeaux, P. 2011. Characteristics of the boundary layer at the bottom of a solitary wave. Coastal Eng., 58, 206-213.http://dx.doi.org/10.1016/j.coastaleng.2010.09.005


Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.