A new formulation for vegetation-induced damping under combined waves and currents

• Published in: Coastal engineering (Amsterdam) Vol. 107; pp. 1 - 13
• Main Authors: Losada, Iñigo J., Maza, Maria, Lara, Javier L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-01-2016
• Subjects: Analytical formulation; Combined waves and currents; Damping; Drag; Exact solutions; Fluid flow; Mathematical analysis; Mathematical models; Plants (organisms); Puccinellia; Real vegetation; Spartina anglica; Vegetation; Wave damping by vegetation; Wave propagation; Analytical formulation; Wave damping by vegetation; Drag; Real vegetation; Combined waves and currents
• ISSN: 0378-3839; 1872-7379
• DOI: 10.1016/j.coastaleng.2015.09.011

Based on energy conservation a new analytical formulation for the evaluation of wave damping under the combined effect of waves and both following and opposing currents is presented. The formulation obtained for regular and random waves allows the derivation of analytical expressions for the vegetation drag coefficient as a function of wave damping parameters. These parameters are calibrated using a unique experimental set obtained in a large-scale wave basin considering the interaction of waves and currents with real vegetation representative of salt marshes, namely Spartina anglica and Puccinellia maritime. Comparisons show the quality of the analytical formulation under different hydrodynamic conditions, vegetation species and various Reynolds numbers formulated in terms of plant characteristics such as the deflected plant length accounting for the flow-induced bending of the vegetation. The new formulation can be useful to be implemented in phase averaged and phase resolving numerical models of wave propagation.
•Vegetation induced damping under the combined effect of waves (regular and random) and following and opposing currents.•3-D experiments in a large-scale basin using two real saltmarsh vegetation species.•Analytical expressions of the vegetation drag coefficients.•Deflection length concept.•New Reynolds number considering vegetation characteristics.