Experimental study of two kinds of hard marine growth effects on the hydrodynamic behavior of a cylinder submitted to wave and current loading
|Author(s)||Marty Antoine1, Schoefs Franck2, Damblans G.3, Facq Jean-Valery1, Gaurier Benoît1, Germain Gregory1|
|Affiliation(s)||1 : Ifremer, Marine Structure Laboratory, 150 Quai Gambetta 62200 Boulogne sur Mer, France
2 : GeM, UMR CNRS 6183, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes, France
3 : France Energies Marines, 525 Avenue Alexis de Rochon, 29280 Brest, France
|Source||Ocean Engineering (0029-8018) (Elsevier BV), 2022-11 , Vol. 263 , P. 112194 (14p.)|
|WOS© Times Cited||2|
|Keyword(s)||Cable, Marine growth, Roughness, Drag coefficient, Coral, Mussel|
The presence of marine growth increases submarine structures diameter and roughness and thus the hydrodynamic loading due to wave and current excitation. In this paper, two kinds of hard roughness (mussels and corals) are studied experimentally. In order to cover a wide range of the dimensionless numbers (Reynolds number, Keulegan–Carpenter number and reduced speed), three kind of trials are carried out: current only, forced motions and a combination of forced motions and current. Two equivalent diameters are used for the calculation of the hydrodynamic coefficients: an equivalent diameter corresponding to the closed volume of the system, where no fluid is permitted, and an equivalent diameter based on the projected area of the colonized structure for the drag coefficient, and on the total volume for inertia coefficients.
Results show that these coefficients are up to 4 times higher than those obtained for a reference cylinder. The use of a different specific diameter for inertia and drag coefficient leads to fit all results with the reference cylinder results. This standardization prove that the knowledge of the volume and the projected surface of the cylindrical structure could simplify the forces estimation applied on the system just by knowing the corresponding smooth one.