Mixing of Stratified Flow around Bridge Piers in Steady Current
Publication: Journal of Hydraulic Engineering
Volume 144, Issue 8
Abstract
This paper presents the results of an experimental and numerical investigation of the mixing of stratified flow around bridge pier structures. In this study, which was carried out in connection with the Fehmarnbelt Fixed Link environmental impact assessment, the mixing processes of two-layer stratification was studied in which the lower level had a higher salinity than the upper layer. The physical experiments investigated two different pier designs. A general study was made regarding forces on the piers in which the effect of the current angle relative to the structure was also included. This was done in uniform flow with no stratification. Following this, a study was performed in which the mixing efficiency was investigated in the case of a stratified flow. The numerical investigations supplemented the findings of the physical experiments and gave information on scale effects, drag coefficients for low velocities, and natural background mixing. The present study provided a general understanding and knowledge about the mixing processes around bridge piers as well as a direct measure of the impact of the proposed designs on the natural stratification.
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Acknowledgments
The research was partly supported by the Femern Bælt A/S, Fehmarnbelt Fixed Link under the reference number ENV010010 and partly by the FP7-OCEAN-2011 project “Innovative Multi-purpose offshore platforms: planning, Design and operation,” MERMAID, 288710, under the call “Ocean of Tomorrow.”
References
Achenbach, E., and E. Heinecke. 1981. “On Vortex shedding from smooth and rough cylinders in the range of Reynolds numbers to .” J. Fluid Mech. 109: 239–251. https://doi.org/10.1017/S002211208100102X.
Arneborg, L., V. Fiekas, L. Umlauf, and H. Burchard. 2007. “Gravity current dynamics and entrainment: A process study based on observations in the Arkona basin.” J. Phys. Oceanogr. 37 (8): 2094–2113. https://doi.org/10.1175/JPO3110.1.
Britter, R. E., J. C. R. Hunt, G. L. Marsh, and W. H. Snyder. 1983. “The effects of stable stratification on turbulent diffusion and the decay of grid turbulence.” J. Fluid Mech. 127: 27–44. https://doi.org/10.1017/S0022112083002591.
Castro, I. P., W. H. Snyder, and P. G. Baines. 1990. “Obstacle drag in stratified flow.” Proc. R. Soc. London A 429 (1876): 119–140. https://doi.org/10.1098/rspa.1990.0054.
Christensen, E. D. 2006. “Large eddy simulation of spilling and plunging breakers.” Coastal Eng. 53 (5–6): 463–485. https://doi.org/10.1016/j.coastaleng.2005.11.001.
de Villiers, E. 2006. “The potential of large eddy simulation for the modeling of wall bounded flows.” Ph.D. thesis. Imperial College of Science, Technology and Medicine.
Fennel, W., and M. Sturm. 1992. “Dynamics of the western Baltic.” J. Mar. Syst. 3 (1–2): 183–205. https://doi.org/10.1016/0924-7963(92)90038-A.
Fernando, H. J. S. 1991. “Turbulent mixing in stratified fluids.” Ann. Rev. Fluid Mech. 23 (1): 455–493. https://doi.org/10.1146/annurev.fl.23.010191.002323.
Fofonoff, N. P., and R. C. Millard Jr. 1983. Algorithms for computation of fundamental properties of saltwater. Paris: UNESCO.
Grubert, J. P. 1989. “Interfacial mixing in stratified channel flows.” J. Hydraul. Eng. 115 (7): 887–905. https://doi.org/10.1061/(ASCE)0733-9429(1989)115:7(887).
Hoerner, S. F. 1965. Fluid dynamic drag. Bricktown, NJ: Hoerner Fluid Dynamics.
Holford, J. M., and P. L. Linden. 1999. “Turbulent mixing in a stratified fluid.” Dyn. Atmos. Oceans 30 (2–4): 173–198. https://doi.org/10.1016/S0377-0265(99)00025-1.
Holmboe, J. 1962. “On the behavior of symmetric waves in stratified shear layers.” Geofys. Publik., Geophysica Norvegica 24: 67–114.
Ivey, G. N., and J. Imberger. 1991. “On the nature of turbulence in a stratified fluid. Part I: The energetics of mixing.” J. Phys. Oceanogr. 21 (5): 650–658. https://doi.org/10.1175/1520-0485(1991)021%3C0650:OTNOTI%3E2.0.CO;2.
Jackson, P. R., and C. R. Rehmann. 2003. “Kinematic effects of differential transport on mixing efficiency in a diffusively stable, turbulent flow.” J. Phys. Oceanogr. 33 (1): 299–304. https://doi.org/10.1175/1520-0485(2003)033%3C0299:KEODTO%3E2.0.CO;2.
Jakobsen, F., I. S. Hansen, N.-E. Ottesen Hansen, and F. Østrup-Rasmussen. 2010. “Flow resistance in the Great Belt, the biggest strait between the North Sea and the Baltic Sea.” Estuarine Coastal Shelf Sci. 87 (2): 325–332. https://doi.org/10.1016/j.ecss.2010.01.014.
Jürgensen, C. 1989. Entrainment introduced by piers, dams, and ships in a stratified channel flow. Lyngby, Denmark: Technical Univ. of Denmark.
Lass, H. U., V. Mohrholz, M. Knoll, and H. Prandke. 2008. “Enhanced mixing downstream of a pile in an estuarine flow.” J. Mar. Syst. 74 (1–2): 505–527. https://doi.org/10.1016/j.jmarsys.2008.04.003.
Linden, P. F. 1979. “Mixing in stratified fluids.” Geophys. Astrophys. Fluid Dyn. 13 (1): 3–23. https://doi.org/10.1080/03091927908243758.
Linden, P. F. 1980. “Mixing across a density interface produced by grid turbulence.” J. Fluid Mech. 100 (4): 691–703. https://doi.org/10.1017/S002211208000136X.
Menon, S., P.-K. Yeung, and W.-W. Kim. 1996. “Effect of subgrid models on the computed interscale energy transfer in isotropic turbulence.” Comput. Fluids 25 (2): 165–180. https://doi.org/10.1016/0045-7930(95)00036-4.
Miller, J. L., and A. Valle-Levinson. 1996. “The effect of bridge piles on stratification in lower Chesapeake bay.” Estuaries 19 (3): 526. https://doi.org/10.2307/1352515.
Møller, J. S., and N.-E. Ottesen Hansen. 1997. “Mixing in startified flow caused by obstacles.” J. Mar. Environ. Eng. 4: 97–111.
Pedersen, F. B. 1986. Environmental hydraulics: Stratified flows. Berlin: Springer.
Peltier, W. R., and C. P. Caulfield. 2003. “Mixing efficiency efficiency in stratified shear flows.” Ann. Rev. Fluid Mech. 35: 135–167. https://doi.org/10.1146/annurev.fluid.35.101101.161144.
Rehmann, C. R. 2004. “Scaling for the mixing efficiency of stratified grid turbulence.” J. Hydraul. Res. 42 (1): 35–42. https://doi.org/10.1080/00221686.2004.9641181.
Rehmann, C. R., and J. R. Koseff. 2004. “Mean potential energy change in stratified grid turbulence.” Dyn. Atmos. Oceans 37 (4): 271–294. https://doi.org/10.1016/j.dynatmoce.2003.09.001.
Rennau, H., S. Schimmels, and H. Burchard. 2012. “On the effect of structure-induced resistance and mixing on inflows into the Baltic Sea: A numerical model study.” Coastal Eng. 60: 53–68. https://doi.org/10.1016/j.coastaleng.2011.08.002.
Rouse, H., and J. Dodu. 1955. “Turbulent diffusion across a density discontinuity.” La Houille Blanche 10 (4): 522–532. https://doi.org/10.1051/lhb/1955050.
Sagaut, P. 2006. Large Eddy simulation for incompressible flows: An introduction. Berlin: Springer.
Smyth, W. D., and K. B. Winters. 2003. “Turbulence and mixing in Holmboe waves.” J. Phys. Oceanogr. 33 (4): 694–711. https://doi.org/10.1175/1520-0485(2003)33%3C694:TAMIHW%3E2.0.CO;2.
Strang, E. J., and H. J. S. Fernando. 2001. “Entrainment and mixing in stratified shear flows.” J. Fluid Mech. 428: 349–386. https://doi.org/10.1017/S0022112000002706.
Trafikministeriet. 1999. Femer bælt-forbindelsen, Forundersøgelser—Resumérapport. København, Denmark: Trafikministeriet.
Turner, J. S. 1968. “The influence of molecular diffusivity on turbulent entrainment across a density interface.” J. Fluid Mech. 33 (4): 639–656. https://doi.org/10.1017/S002211206800159X.
Turner, J. S. 1973. Buoyancy effects in fluids. London: Cambridge University Press.
Yoshizawa, A. 1986. “Statistical theory for compressible turbulent shear flows, with the application to subgrid modeling.” Phys. Fluids 29 (7): 2152–2164. https://doi.org/10.1063/1.865552.
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©2018 American Society of Civil Engineers.
History
Received: Aug 7, 2017
Accepted: Jan 5, 2018
Published online: May 18, 2018
Published in print: Aug 1, 2018
Discussion open until: Oct 18, 2018
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