A SIMPLE AND ACCURATE NONLINEAR METHOD FOR RECOVERING THE SURFACE WAVE ELEVATION FROM PRESSURE MEASUREMENTS

  • Philippe Bonneton
  • Arthur Mouragues
  • David Lannes
  • Kevin Martins
  • Hervé Michallet

Abstract

Near-bottom-mounted pressure sensors have long been used for measuring surface wave in the nearshore. The commonly used practice is to recover the wave field by means of a transfer function based on linear wave theory (e.g. Guza and Thornton, 1980; Bishop and Donelan, 1987). However, wave nonlinearities can be strong in the shoaling zone, especially in the region close to the onset of breaking, and thus the use of a linear theory can be questioned. Martins et al. (2017) and Bonneton (2017, 2018) have shown that the linear reconstruction fails to describe the peaky and skewed shape of nonlinear waves prior to breaking, with wave height errors up to 30%. Such measurement errors are problematic for many coastal applications. For instance, studies on wave overtopping and submersion require accurate measurements of the highest wave crests. Furthermore, a correct description of wave asymmetry and skewness is of paramount importance for understanding sediment dynamics. Finally, an accurate description of the wave elevation field is also crucial for the validation of the new generation of fully-nonlinear phase-resolving wave models.

References

Bishop, C. T., and Donelan, M. A. (1987). Measuring waves with pressure transducers. Coastal Engineering, 11(4), 309-328.

Bonneton, P., and Lannes, D. (2017). Recovering water wave elevation from pressure measurements. Journal of Fluid Mechanics. 833, 399-429.

Bonneton, P., Lannes, D, Martins, K. and Michallet, H. (2018). A nonlinear weakly dispersive method for recovering the surface wave elevation from pressure measurements. In press in Coastal Eng.

Guza, R. T., and Thornton, E.B. (1980), Local and shoaled comparisons of sea surface elevations, pressures, and velocities, J. Geophys. Res., 85(C3), 1524-1530

Martins, K., Blenkinsopp, C.E, Almar, R., Zang, Z., (2017). On the influence of swash-based reflection on surf zone hydrodynamics: a wave-by-wave approach. Coastal Eng., 122, 27-43.

Michallet, H., Barthélemy, E., Lammens, A., Marin, G. and Vaudelin, G. (2017). Bed motion under waves: plug and sheet flow observations. Coastal Dynamics 2017.

Published
2018-12-30
How to Cite
Bonneton, P., Mouragues, A., Lannes, D., Martins, K., & Michallet, H. (2018). A SIMPLE AND ACCURATE NONLINEAR METHOD FOR RECOVERING THE SURFACE WAVE ELEVATION FROM PRESSURE MEASUREMENTS. Coastal Engineering Proceedings, 1(36), waves.46. https://doi.org/10.9753/icce.v36.waves.46