Fully Nonlinear Potential Flow Simulations of Wave Shoaling Over Slopes: Spilling Breaker Model and Integral Wave Proper
- PDF / 2,149,229 Bytes
- 35 Pages / 439.37 x 666.142 pts Page_size
- 59 Downloads / 172 Views
Fully Nonlinear Potential Flow Simulations of Wave Shoaling Over Slopes: Spilling Breaker Model and Integral Wave Properties Stephan T. Grilli1
· Juan Horrillo2 · Stéphan Guignard3
Received: 1 April 2019 / Accepted: 23 September 2019 © Springer Nature Switzerland AG 2019
Abstract A spilling breaker model (SBM) is implemented in an existing two-dimensional (2D) numerical wave tank (NWT), based on fully nonlinear potential flow (FNPF) theory and the boundary element method (BEM), in which an absorbing surface pressure is specified over the crest of impending breaking waves (detected based on a maximum front slope criterion) to simulate the power dissipated during breaking. The latter is calibrated to match that of a hydraulic jump of parameters identical to local wave properties (height, celerity, . . .). Although this model is not aimed at being fully physical in the surfzone, it allows more accurately simulating properties of fully nonlinear shoaling waves than standard empirical absorbing beaches (AB). After assessing the convergence with the discretization of 2D-NWT results for strongly nonlinear shoaling waves, simulations are first validated based on laboratory experiments for non-breaking and breaking waves, shoaling up a mild slope; a good agreement is found between both. The NWT is then used to compute fully nonlinear local (height, celerity, asymmetry) and integral (mean-water-level, radiation stress) properties of periodic waves shoaling over mild slopes. Discrepancies with standard results of wave theories are discussed in light of fully nonlinear effects modeled in the NWT. While only periodic waves are considered here, the SBM could be applied to shoaling irregular waves, for which the breaking point location will constantly vary, which would be advantageous compared to an AB fixed in space. For such cases, besides its more physical energy absorption, the SBM would allow better preventing wave overturning that may occur far from shore due to nonlinear wave–wave interactions and otherwise interrupt the FNPF–NWT simulations. Keywords Nonlinear nearshore wave transformations · Wave shoaling and breaking · Numerical wave tank · Breaker model · Boundary element method Abbreviations 2D Two-dimensional
Extended author information available on the last page of the article
123
S. T. Grilli et al.
3D AB AP BEM BIE BM BP FNPF FSWT LWT MII MWL NWT RMS SBM SFW VOF WM
Three-dimensional Absorbing beach Absorbing piston wavemaker Boundary element method Boundary integral equation Boussinesq model Breaking point Fully nonlinear potential flow Fourier steady wave theory Linear wave theory Middle interval interpolation Mean water level (wave-period averaged) Numerical wave tank Root mean square Spilling breaker model Stream function waves Volume of fluid Wavemaker
1 Introduction Since the seminal work of Longuet-Higgins and Cokelet [75], increasingly efficient and generic numerical models were developed to simulate nonlinear ocean waves based on fully nonlinear potential flow (FNPF) equations, i.e., Euler equati
Data Loading...
