| Summary: | <br xmlns:etd="http://www.ouls.ox.ac.uk/ora/modsextensions"><strong>Background: </strong>Focused wave groups offer a means for coastal engineers to determine extreme run-up and overtopping events.</br><br xmlns:etd="http://www.ouls.ox.ac.uk/ora/modsextensions"><strong>Research purpose: </strong>This work examines numerically the importance of second-order accurate laboratory wave generation for New Wave-type focused wave groups generated by a piston-type paddle generator, and interacting with a plane beach and a seawall in a wave basin.</br><br xmlns:etd="http://www.ouls.ox.ac.uk/ora/modsextensions"><strong>Methods: </strong>The numerical wave tank is based on the Boussinesq equations for non-breaking waves, and the non-linear shallow water equations for broken waves. During the model validation, good agreement is achieved between the numerical predictions and laboratory measurements of free surface elevation, run-up distances andovertopping volumes for the test cases driven by linear paddle signals. Errors in run-up distance and overtopping volume, arising from linear wave generation, are then assessed numerically by repeating the test cases using second-order accurate paddle signals.</br><br xmlns:etd="http://www.ouls.ox.ac.uk/ora/modsextensions"><strong>Results: </strong>Focused wave groups generated using first-order wave-maker theory are found to be substantially contaminated by a preceding long error wave, resulting in erroneously enhanced run-up distances and overtoppingvolumes.</br><br xmlns:etd="http://www.ouls.ox.ac.uk/ora/modsextensions"><strong>Conclusions: </strong>Thus, the use of second-order wave-maker theory for wave group run-up and overtopping experiments is instead recommended.</br>
|
|---|