FN Archimer Export Format
PT J
TI Experimental investigation of the turbulent wake past real seabed elements for velocity variations characterization in the water column.
BT 
AF Ikhennicheu, Maria
   Germain, Gregory
   Druault, Philippe
   Gaurier, Benoit
AS 1:1;2:1;3:2;4:1;
FF 1:PDG-REM-RDT-LCSM;2:PDG-REM-RDT-LCSM;3:;4:PDG-REM-RDT-LCSM;
C1 Ifremer, Marine Structure Laboratory, 150 Quai Gambetta Boulogne sur Mer 62200, France
   Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 7190, Institut Jean Le Rond d’Alembert, Paris F-75005, France
C2 IFREMER, FRANCE
   UNIV PARIS 06, FRANCE
SI BOULOGNE
SE PDG-REM-RDT-LCSM
IN WOS Ifremer UPR
   copubli-france
   copubli-univ-france
IF 2.073
TC 17
UR https://archimer.ifremer.fr/doc/00502/61356/64997.pdf
LA English
DT Article
DE ;Turbulence;Experimental trials;Wall-mounted obstacles;PIV;LDV;Marine energy
AB In high flow velocity areas like those suitable for marine energy application, bathymetry variations create strong velocity fluctuations in the water column. It is therefore essential to characterize the turbulence evolution in the wake of seabed elements which may impact the loads on tidal turbines. For that purpose, experiments are carried out in a flume tank with Re as high as achievable in Froude similitude, with bathymetry variations experimentally represented with various wall-mounted square elements of height H: a cylinder or a cube as unitary obstacles and combinations of these elements followed by an inclined floor to resemble smooth bathymetry changes. The onset flow is a simple boundary layer profile with height 1.3 H and a low turbulence intensity. PIV and LDV measurements are used to investigate the wake past all test cases in order to distinguish high floor elevation cases (unitary obstacles) from mean roughness effect (obstacle combinations). Results show that the obstacle combinations produce a wake less extended than for a single wide cylinder that produces an extended wake and very energetic turbulent events. With a single cube, no downstream development of large turbulent events exist and the wake reduces by a factor of 3 compared to the wake cylinder case. An inclined floor downstream of a single wall-mounted obstacle reduces its wake length but does not alter the turbulent structures shed. Turbulent velocity profiles extracted from every wake topology investigated are also compared. The general conclusion is that: for small aspect ratio cases, the obstacle will not affect the water column. On the contrary, strong energetic turbulent events are emitted from large aspect ratio obstacles. Combinations cases stand in-between. 
PY 2019
PD AUG
SO International Journal Of Heat And Fluid Flow
SN 0142-727X
PU Elsevier BV
VL 78
UT 000478708700010
DI 10.1016/j.ijheatfluidflow.2019.108426
ID 61356
ER

EF