APPLICATION OF SMOOTHED PARTICLE HYDRODYNAMICS (SPH) IN NEARSHORE MIXING: A COMPARISON TO LABORATORY DATA

Soroush Abolfathi, Jonathan Pearson

Abstract


A weakly compressible smoothed particle hydrodynamics (WCSPH) method is used to simulate the nearshore flow hydrodynamics. The wave induced dispersion and diffusion are determined for monochromatic waves with significant wave height of 0.12 m and the wave period of 1.2 sec (Sop=5%) based on WCSPH wave dynamics. The hydrodynamics of WCSPH model are compared to the laboratory results obtained from series of LDA measurements. The overall mixing coefficients across the nearshore are determined from WCSPH hydrodynamics. The mixing coefficients obtained are compared with the values determined from a series of fluorometric studies performed in a large-scale facility in DHI, Denmark. The results show that the wave profiles are in good agreement with the experimental data. The WCSPH model is proven to be well capable of estimating the dispersion across the nearshore.

Keywords


WCSPH; Dispersion; Diffusion; nearshore mixing; LDA

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References


Abolfathi, S. 2017. Nearshore Mixing due to the effects of waves and current. PhD thesis, University of Warwick.

Abolfathi, S. and J. M. Pearson. 2014. Solute dispersion in the nearshore due to oblique waves, Proceedings of 14th International Conference on Coastal Engineering, ASCE, 1(34), waves 49.

Bowen, A. J. & D. L. Inman, 1974. Nearshore mixing due to waves and wave-induced currents. Rapp. P.-v. Reun. Cons. int. Explor. Mer, 167: 6-12.

Chikwendu S. C. 1986. Calculation of longshore shear dispersivity using an N-zone model, J. Fluid Mech., 167, 19-30.

Clark D. B., L. Lenain, F. Feddersen, E. Boss, and R. T. Guza. 2014. Aerial imaging of fluorescent dye in the nearshore, J. Atmos. Oceanic Tech., 31, 1410-1421.

Feddersen, F. 2007. Breaking wave induced cross-shore tracer dispersion in the surfzone: Model results and scalings, J. Geophys. Res.,112, C0912.

George, R., R. E. Flick, R. T. GUZA. 1994. Observations of turbulence in the surf zone. J. Geophys. Res., 99, 801–810.

Goring D. G., V. I. Nikora, 2002. Despiking acoustic Doppler velocimeter data. J. of Hydraulic Eng., vol. 128, 117 – 126.

Gotoh, H., Shibahara, T. & T. Sakai, 2001. Sub-particle-scale turbulence model for the MPS method Lagrangian flow model for hydraulic engineering, J. Comp. Fluid Dyn. 9(4), 339- 347.

Grant S. B., J. H. Kim, B. H. Jones, S. A. Jenkins, J. Wasyl, C. Cudaback. 2005. Surf zone entrainment, along-shore transport, and human health implications of pollution from tidal outlets. Journal of Geophysical Research., 110 (C10).

Harris, T. F. W., Jordan, J. M., W. R. McMurry, C. J. Verwey, F. P. Anderson, 1963. Mixing in the surf zone. Int. J. Air Wat. Pollut., 7: 649-67.

Inman D. L., F. J. Tait & C. E. Nordstrom. 1971. Mixing in the surf zone. J. geophys. Res., 76: 3493.

List E. J., G. Gartrell, C. D. Winant, 1990. ‘Diffusion and Dispersion in Coastal Waters’, Journal of Hydraulic Engineering, 116(10), 1158-1179

Madsen, O. S. 1971. On the generation of long waves, Journal of Geophysical Research, 76(36).

Monaghan, J.J. 1994. Simulating free surface flows with SPH. Comp. Physics. 110, 399 - 406.

Nadaoka, K., T. Kondoh, 1982. Laboratory measurements of velocity field structure in the surf zone by LDV. Coastal Engng. Japan, 25,125-145.

Pearson, J. M., I. Guymer, L. E. Coastes, J. R. West. 2002. Effect of wave height on on-off shore solute mixing. J. Wtrwy., Port, Coast., and Oc. Engng., ASCE. 1-11.

Pearson, J. M., I. Guymer, L. E. Coastes, J. R. West. 2009. On-off shore Solute Mixing in the Surf-Zone. J. Wtrwy., Port, Coast., and Oc. Engng., ASCE. Vol 135, No. 4.

Pearson, J. M., I. Guymer, T. V. Karambas., O. S. Petersen. 2006. Laboratory investigation of Mixing in the Nearshore. Proc. 30th Int. Conf. Coastal Eng. San Diego

Spydell M., F. Feddersen, R. T. Guza, W. Schmidt., 2007. Observing surfzone dispersion with drifters, J. Phys. Oceangraphy., 37, 2920-2939.

Svendsen, I. A. & U. Putrevu. 1994. Near-shore mixing and dispersion. Proc. R. Soc. London, Ser. A, 445, 561-576.

Takewaka, S., S. Misaki, T. Nakamura, 2003. Dye diffusion experiment in a longshore, current field, Coastal Engineering Journal, World Scientific Publishing Company and Japan Society of Civil Engineers. 45(3), 471-487.

Taylor G. I., 1954. The dispersion of matter in a turbulent flow through a pipe. Proc. R. Soc. London, Ser. A, 223, 446-468.

Tseng R. S., 2001. ‘On the Dispersion and Diffusion near Estuaries and around Islands’, Estuarine Coastal and Shelf Science, v54, 89-100.

Trowbridge J., S. Elgars., 2001. Turbulence measurements in the surfzone, J. Phys.Oceanogr.,31.2403.

Yeganeh-Bakhtiary, A., H. Houshangi, F. Hajivalie, and S. Abolfathi. 2017. A Numerical Study on the Hydrodynamics of Standing Waves in front of Caisson Breakwaters by a WCSPH Model. Coastal Engineering Journal, Volume 59(2): 1750005.




DOI: https://doi.org/10.9753/icce.v35.currents.16