|
|
|
|
|
| Bouhoubeiny, Elkhadim; Germain, Gregory; Druault, Philippe. |
| Flow field measurements past a fixed rigid cod-end structure and past a porous fishing net structure are conducted using Time-Resolved PIV method. The rigid cod-end is first used to characterize finely the wake flow. Proper Orthogonal Decomposition (POD) is then applied in order to extract the large scale energetic vortices of the flow from the measured velocity field. It is then observed that the first POD modes are associated to the Karman's type flow structure of vortex shedding. It is shown that the characteristics of the wake flow behind the rigid cod-end flow configuration compare quite well with previous ones obtained from bluff cylinder or sphere wake analyzes. Second, PIV measurements are performed around a non-rigid bottom trawl which is free to... |
| Tipo: Text |
Palavras-chave: Fishing gear; PIV measurements; Vortex shedding; Proper Orthogonal Decomposition. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00027/13820/11046.pdf |
| |
|
|
| Resseguier, Valentin; Memin, Etienne; Chapron, Bertrand. |
| In large-scale Fluids Dynamics systems, the velocity lives in a broad range of scales. To be able to simulate its large-scale component, the flow can be de- composed into a finite variation process, which represents a smooth large-scale velocity component, and a martingale part, associated to the highly oscillating small-scale velocities. Within this general framework, a stochastic representation of the Navier-Stokes equations can be derived, based on physical conservation laws. In this equation, a diffusive sub-grid tensor appears naturally and gener- alizes classical sub-grid tensors. Here, a dimensionally reduced large-scale simulation is performed. A Galerkin projection of our Navier-Stokes equation is done on a Proper Orthogonal De- composition basis.... |
| Tipo: Text |
Palavras-chave: Stochastic calculus; Uid dynamics; Large eddy simulation; Proper Orthogonal Decomposition; Reduced order model; Uncertainty quantification. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00320/43080/42607.pdf |
| |
|
|
|
