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Deparday, Julien; Bot, Patrick; Hauville, Frédéric; Augier, Benoit; Rabaud, Marc; Motta, Dario; Le Pelley, David. |
While sailing offwind, the trimmer typically adjusts the downwind sail “on the verge of luffing”, occasionally letting the luff of the sail flap. Due to the unsteadiness of the spinnaker itself, maintaining the luff on the verge of luffing requires continual adjustments. The propulsive force generated by the offwind sail depends on this trimming and is highly fluctuating. During a flapping sequence, the aerodynamic load can fluctuate by 50% of the average load. On a J/80 class yacht, we simultaneously measured time-resolved pressures on the spinnaker, aerodynamic loads, boat data and wind data. Significant spatio-temporal patterns were detected in the pressure distribution. In this paper we present averages and main fluctuations of pressure distributions... |
Tipo: Text |
Palavras-chave: Full scale experiment; Instrumented boat; Spinnaker; Fluid structure interaction; POD; Unsteady. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00597/70918/69156.pdf |
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Aubin, Nicolas; Augier, Benoit; Sacher, Matthieu; Bot, Patrick; Hauville, Frédéric; Flay, Richard G.j.. |
An experiment was performed in the Yacht Research Unit’s Twisted Flow Wind Tunnel (University of Auckland) to test the effect of dynamic trimming on three IMOCA 60 inspired mainsail models in an upwind (βAW = 60°) unheeled configuration. This study presents dynamic fluid structureinteractionresultsinwellcontrolledconditions(wind,sheetlength)withadynamictrimming system. Trimming oscillations are done around an optimum value of CFobj previously found with a static trim. Different oscillation amplitudes and frequencies of trimming are investigated. Measurements are done with a 6 component force balance and a load sensor giving access to the unsteady mainsail sheet load. The driving CFx and optimization target CFobj coefficient first decrease at low reduced... |
Tipo: Text |
Palavras-chave: Wind tunnel; Upwind; Unsteady; Fluid-structure interaction. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00597/70919/69157.pdf |
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