Shan-Hwei Ou, Tai-Wen Hsu, Jian-Feng Lin, Jian-Wu Lai, Shih-Hsiang Lin, Chen-Chen Chang, Yuan-Jyh Lan


A laboratory measurement on the flow field, turbulence and wave energy of spilling breakers over artificial reefs is presented. Instantaneous velocity fields of propagating breaking waves on artificial reefs were measured using Particle Image Velocimeter (PIV) and Bubble Image Velocimeter (BIV). Variations of water surface elevation were observed by using Charge Coupled Device (CCD) cameras with horizontal posture. The experimental results showed that the initial bubble velocity in the aerated region is faster than phase speed with a factor of 1.26. The velocity profiles are identical to the shallow water theory. It is found that a low flow velocity exists due to an opposite but equal onshore and offshore velocity. Significant turbulent kinetic energy and turbulent Reynolds stress are produced by breaking waves in the front of aerated region, then move offshore and decay. The calculated total energy dissipation rate was compared to that based on a bore approximation.


DIP; PIV; BIV; Breaking wave

Full Text:



Chang, K. A. and Liu, P. F., 1998, Velocity, Acceleration and Vorticity under a Breaking Wave, Physical of Fluids, Vol. 10, pp. 327–329. http://dx.doi.org/10.1063/1.869544

Chang, K. A., Hsu, T. J. and Liu, P. F., 2001, Vortex Generation and Evolution in Water Waves Propagating over a Submerged Rectangular Obstacle, Part I. Solitary Waves, Coastal Engineering, Vol. 44, pp. 13-36. http://dx.doi.org/10.1016/S0378-3839(01)00019-9

Greated, C. A. and Emarat, N., 2000, Optical Studies of Wave Kinematics, Advances in Coastal and Ocean Engineering, Vol. 6, ed P L-F Liu (Singapore: World Scientific) pp 185–223.

Govender, K., Mocke, G.P. and Alport, M.J., 2002, Videoimaged surf zone wave and roller structures and flow fields, Journal of Geophysical Research, 107(C10), 3177.

Hassan, Y. A., Schmidl, W. D. and Ortiz-Villafuerte, J., 1998, Investigation of Three-dimensional Two-phase Flow Structure in a Bubbly Pipe, Measurement Science Technology, Vol. 9, pp.309–326. http://dx.doi.org/10.1088/0957-0233/9/3/003

Jansen, P. C. M., 1986, Laboratory Observations of the Kinematics in the Aerated Region of Breaking Waves, Coastal Engineering, Vol.9, pp. 453–477. http://dx.doi.org/10.1016/0378-3839(86)90008-6

Lindken, R. and Merzkirch, W., 2002, A Novel PIV Technique for Measurements in Multi-Phase Flows and Its Application to Two-Phase Bubbly Flows, Experiments in Fluids, Vol. 33, pp.814-825.

Nishino, K., Kato, H. and Torii, K., 2000, Stereo Imaging for Simultaneous Measurement of Size and Velocity of Particles in Dispersed Two-Phase Flow, Measurement Science Technology, Vol. 11,pp.633–645. http://dx.doi.org/10.1088/0957-0233/11/6/306

Perlin, M., He, J. and Bernal, L. P., 1996, An Experimental Study of Deep Water Plunging Breakers, Physics of Fluids, Vol. 8, pp.2365–2274. http://dx.doi.org/10.1063/1.869021

Petti, M., Quinn, P. A., Liberatore, G. and Easson, W. J., 1994, Wave Velocity Field Measurement over a Submerged Breakwater, Proceeding 24th International Conference Coastal Engineering, Japan, ASCE, pp. 525-539.

Ryu, Y., Chang, K. A. and Lim, H. J., 2005, Use of Bubble Image Velocimetry for Measurement of Plunging Wave Impinging on Structure and Associated Greenwater, Measurement Science and Technology, Vol. 16, pp.1945-1953. http://dx.doi.org/10.1088/0957-0233/16/10/009

Takashi, Y., Hidenmi, M. and Natsuki, M., 1997, Kinematics of Overturning Solitary Waves and Their Relations to Breaker Types, Coastal Engineering, Vol. 29, pp. 317-346. http://dx.doi.org/10.1016/S0378-3839(96)00032-4

Ting, F. C. K. and Kim, Y. K., 1994, Vortex Generation in Water Waves Propagation over a Submerged Obstacle, Coastal Engineering, Vol. 24, pp.23-49. http://dx.doi.org/10.1016/0378-3839(94)90025-6

Ting, F. C. K. and Kirby, J. T., 1994 Observation of Undertow and Turbulence in a Laboratory Surf Zone, Coastal Engineering, Vol. 24, pp.51–80. http://dx.doi.org/10.1016/0378-3839(94)90026-4

Ting, F. C. K. and Kirby, J. T., 1995, Dynamics of Surf-Zone Turbulence in a Strong Plunging Breaker, Coastal Engineering, Vol. 24, pp.177–204. http://dx.doi.org/10.1016/0378-3839(94)00036-W

Yasuda, T., Mutsuda, H. and Mizutani, 1997, N., Kinematics of overturning solitary waves and their relations to breaker types, Coastal Engineering, pp. 317-346. http://dx.doi.org/10.1016/S0378-3839(96)00032-4

DOI: http://dx.doi.org/10.9753/icce.v32.waves.17