Abstract
The object of present study is to investigate the bed shear stress on a slope under regular breaking waves by a novel instrument named Micro-Electro-Mechanical System (MEMS) flexible hot-film shear stress sensor. The sensors were calibrated before application, and then a wave flume experiment was conducted to study the bed shear stress for the case of regular waves spilling and plunging on a 1:15 smooth PVC slope. The experiment shows that the sensor is feasible for the measurement of the bed shear stress under breaking waves. For regular incident waves, the bed shear stress is mainly periodic in both outside and inside the breaking point. The fluctuations of the bed shear stress increase significantly after waves breaking due to the turbulence and vortexes generated by breaking waves. For plunging breaker, the extreme value of the mean maximum bed shear stress appears after the plunging point, and the more violent the wave breaks, the more dramatic increase of the maximum bed shear stress will occur. For spilling breaker, the increase of the maximum bed shear stress along the slope is gradual compared with the plunging breaker. At last, an empirical equation about the relationship between the maximum bed shear stress and the surf similarity parameter is given, which can be used to estimate the maximum bed shear stress under breaking waves in practice.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Barnes, M.P., O’Donoghue, T., Alsina, J.M. and Baldock, T.E., 2009. Direct bed shear stress measurements in bore-driven swash, Coastal Engineering, 56(8), 853–867.
Boers, M., 2005. Surf Zone Turbulence, Ph.D. Thesis, Delft University of Technology, Netherlands.
Carstensen, S., Sumer, B.M. and Fredsøe, J., 2010. Coherent structures in wave boundary layers. Part 1. Oscillatory motion, Journal of Fluid Mechanics, 646, 169–206.
Cox, D.T., Kobayashi, N. and Okayasu, A., 1996. Bottom shear stress in the surf zone, Journal of Geophysical Research, 101(C6), 14337–14348.
Deigaard, R., Mikkelsen, M.B. and Fredsøe, J., 1991. Measurements of the Bed Shear Stress in A Surf Zone, Prog. Rep. 73, Institute of Hydrodynamics and Hydraulic Engineering, Technical University of Denmark, Lyngby, 21–30.
Fredsøe, J. and Deigaard, R., 1992. Mechanics of Coastal Sediment Transport, World Scientific Publishing Company, Singapore.
Fredsøe, J., Sumer, B.M., Kozakiewicz, A., Chua, L.H.C. and Deigaard, R., 2003. Effect of externally generated turbulence on wave boundary layer, Coastal Engineering, 49(3), 155–183.
Galvin, C.J.Jr., 1968. Breaker type classification on three laboratory beaches, Journal of Geophysical Research, 73(12), 3651–3659.
Hanratty, T.J. and Campbell, J.A., 1996. Measurement of wall shear stress, in: Goldstein, R.J. (ed.), Fluid Mechanics Meaurements, 2nd ed., Taylor & Francis, Washington, D.C., 575–648.
Huang, H.L., Zuo, Q.H., Zhou, Y.R., Shen, Y.S. and Li, L.X., 2016. Design of measuring instrument with whole direct method for bed shear stress under two-dimensional water-flow co-action, China Ocean Engineering, 30(6), 916–925.
Hultmark, M. and Smits, A.J., 2010. Temperature corrections for constant temperature and constant current hot-wire anemometers, Measurement Science and Technology, 21(10), 105404.
Huo, G., Wang, Y.G., Yin, B.S. and You, Z.J., 2007. A new measure for direct measurement of the bed shear stress of wave boundary layer in wave flume, Journal of Hydrodynamics, Ser. B, 19(4), 517–524.
Jensen, B.L., Sumer, B.M. and Fredsøe, J., 1989. Turbulent oscillatory boundary layers at high Reynolds numbers, Journal of Fluid Mechanics, 206, 265–297.
Knight, D.W., Demetriou, J.D. and Hamed, M.E., 1984. Boundary shear in smooth rectangular channels, Journal of Hydraulic Engineering, 110(4), 405–422.
Ma, B.H., Ren, J.Z., Deng, J.J. and Yuan, W.Z., 2010. Flexible thermal sensor array on PI film substrate for underwater applications, Proceedings of the 23rd International Conference on Micro Electro Mechanical Systems (MEMS), IEEE, Wanchai, Hong Kong, 679–682.
Mirfenderesk, H. and Young, I.R., 2003. Direct measurements of the bottom friction factor beneath surface gravity waves, Applied Ocean Research, 25(5), 269–287.
Musumeci, R.E., Marletta, V., Andò, B., Baglio, S. and Foti, E., 2015. Measurement of wave near-bed velocity and bottom shear stress by ferrofluids, IEEE Transactions on Instrumentation and Measurement, 64(5), 1224–1231.
Pujara, N. and Liu, P.L.F., 2014. Direct measurements of local bed shear stress in the presence of pressure gradients, Experiments in Fluids, 55, 1767.
Schlichting, H. and Gersten, K., 2017. Boundary-layer Theory, 9th ed., Springer, Berlin.
Seelam, J.K., Guard, P.A. and Baldock, T.E., 2011. Measurement and modeling of bed shear stress under solitary waves, Coastal Engineering, 58(9), 937–947.
Soulsby, R., 1997. Dynamics of Marine Sands: A Manual for Practical Applications, Thomas Telford, London.
Sumer, B.M., Arnskov, M.M., Christiansen, N. and Jørgensen, F.E., 1993. Two-component hot-film probe for measurements of wall shear stress, Experiments in Fluids, 15(6), 380–384.
Sumer, B.M., Sen, M.B., Karagali, I., Ceren, B., Fredsøe, J., Sottile, M., Zilioli, L. and Fuhrman, D.R., 2011. Flow and sediment transport induced by a plunging solitary wave, Journal of Geophysical Research, 116(C1), C01008.
Sumer, B.M., Guner, H., Hansen, N.M., Fuhrman, D.R. and Fredsøe, J., 2013. Laboratory observations of flow and sediment transport induced by plunging regular waves, Journal of Geophysical Research: Oceans, 118(11), 6161–6182.
Xu, H., Xia, Y.F., Ma, B.H., Hao, S.Y., Zhang, S.Z. and Du, D.J., 2015. Research on measurement of bed shear stress under wave-current interaction, China Ocean Engineering, 29(4), 589–598.
Yüksel, Y., Çevik, E.Ö. and Kapdansli, S., 1998. Bed shear stress distribution over beach profiles, Journal of Coastal Research, 14(3), 1044–1053.
You, Z.J. and Yin, B.S., 2007. Direct measurement of bottom shear stress under water waves, Journal of Coastal Research, 50, 1132–1136.
Acknowledgments
The authors gratefully acknowledge the research team of Prof. MA Bing-he from Northwestern Polytechnical University for providing the MEMS flexible hot-film shear stress sensor and the engineering prototype. We would like to thank Prof. Jørgen Fredsøe and Dr. Nilas Mandrup Hansen for providing some of the literature.
Author information
Authors and Affiliations
Corresponding author
Additional information
Foundation item: This study was financially supported by the National Key Scientific Instrument and Equipment Development Project (Grant No. 2013YQ04091108) and the National Natural Science Foundation of China (Grant No. 51309158).
Rights and permissions
About this article
Cite this article
Hao, Sy., Xia, Yf. & Xu, H. Experimental study on the bed shear stress under breaking waves. China Ocean Eng 31, 308–316 (2017). https://doi.org/10.1007/s13344-017-0036-z
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13344-017-0036-z