Next Article in Journal
A Study on the Wind Energy Potential in the Romanian Coastal Environment
Next Article in Special Issue
Stochastic Modeling of Forces on Jacket-Type Offshore Structures Colonized by Marine Growth
Previous Article in Journal
Effect of Girder Spacing and Depth on the Solitary Wave Impact on Coastal Bridge Deck for Different Airgaps
Previous Article in Special Issue
Towing Operation Methods of Offshore Integrated Meteorological Mast for Offshore Wind Farms
Open AccessArticle

Numerical Analyses of Wave Generation and Vortex Formation under the Action of Viscous Fluid Flows over a Depression

1
Department of Information Management, Ling-Tung University, Taichung 408, Taiwan
2
Natural Science Division in General Education Center, Ling-Tung University, Taichung 408, Taiwan
J. Mar. Sci. Eng. 2019, 7(5), 141; https://doi.org/10.3390/jmse7050141
Received: 21 March 2019 / Revised: 4 May 2019 / Accepted: 4 May 2019 / Published: 12 May 2019
(This article belongs to the Special Issue Marine Structures)
Transient free-surface deformations and evolving vortices due to the passage of flows over a submerged cavity are simulated. A two-dimensional stream function–vorticity formulation with a free-surface model is employed. Model results are validated against the limiting case of pure lid-driven cavity flow with comparisons of the vortical flow pattern and velocity profiles. The verification of the free-surface computations are also carried out by comparing results with published potential flow solutions for cases of flows over a depressed bottom topography. The agreements are generally good. Investigations are extended to other viscous flow conditions, where the cavity is set to have the normalized dimension of one by one when scaled by the still water depth. The free-surface elevations and streamline patterns for cases with Froude numbers ranging from 0.5 to 1.1 and different Reynolds numbers (Re = 5000 and 500) are calculated. At the condition of near-critical flow (Fr ≈ 1.0), the phenomenon of upstream advancing solitons is produced. Viscous effects on the free-surface profile reveal that at a lower value of Re (e.g., Re = 500) larger advancing solitary waves are generated. Vortical flow patterns in the cavity are examined for the cases with Fr = 1.0 and various values of Re. When Re = 5000, the vortex pattern includes a primary and a weak, but dominated secondary vortices at the time reaching a nearly quasi-steady motion. For the case of lower Re (e.g., Re = 500), a steady-state vortex pattern can be established with a clockwise primary vortex mostly occupied inside the cavity. View Full-Text
Keywords: solitons; free-surface flow; depressed bottom; viscous fluid flow; vortical flow solitons; free-surface flow; depressed bottom; viscous fluid flow; vortical flow
Show Figures

Figure 1

MDPI and ACS Style

Chang, C.-H. Numerical Analyses of Wave Generation and Vortex Formation under the Action of Viscous Fluid Flows over a Depression. J. Mar. Sci. Eng. 2019, 7, 141.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop