Full-scale flying shape measurement of offwind yacht sails with photogrammetry
TypeArticles dans des revues avec comité de lecture
Yacht downwind sails are complex to study due to their non-developable shape with high camber and massively detached flow around thin and flexible membranes. Numerical simulations can now simulate this strong fluid-structure interaction, but need experimental validation. It remains complex to measure spinnaker flying shapes partly because of their inherent instability, like luff flapping. This work presents full-scale experimental investigation of spinnaker shapes with simultaneous measurement of aerodynamic loads on the three sail corners, with navigation and wind data. The experimental set-up and photogrammetric method are presented. Results are analysed in the whole range of apparent wind angle for this sail. The spinnaker shape shows dramatic variations and high discrepancies with the design shape. The photogrammetric measurement produces the full 3D flying shape with a satisfactory accuracy. Even if only steady state results are given here, this new system enables time-resolved measurement of flying shapes and thus flapping of spinnakers to be investigated, which is valuable for yacht performance optimisation. On top of sailing yacht applications, the method is useful in any application where a non-developable 3D shape is to be determined, and particularly when it results from the Fluid Structure Interaction of a flexible structure with a complex flow.
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DEPARDAY, Julien; BOT, Patrick; HAUVILLE, Frédéric; AUGIER, Benoit; RABAUD, Marc; MOTTA, Dario; LE PELLEY, David (SNAME, 2017)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 ...
Performance enhancement of downwind sails due to leading edge flapping: A wind tunnel investigation AUBIN, Nicolas; AUGIER, Benoit; DEPARDAY, Julien; SACHER, Matthieu; BOT, Patrick (Elsevier BV, 2018)This work presents a wind tunnel experimental study on the effect of the leading edge flapping on the aerodynamic performance of a spinnaker. Four J80-class spinnaker models, combining two different assembling structures ...
Experimental analysis of a strong fluid–structure interaction on a soft membrane — Application to the flapping of a yacht downwind sail DEPARDAY, Julien; AUGIER, Benoit; BOT, Patrick (Elsevier BV, 2018-08)In the present study we investigate the flapping instability of a light, soft, highly cambered membrane subject to wind loading. An original in-situ experiment is developed where time-resolved pressures and forces are ...
AUGIER, Benoit; BOT, Patrick; HAUVILLE, Frédéric; DURAND, Mathieu (Editions de l'Ecole Polytechnique, 2013)The dynamic Fluid Structure Interaction (FSI) of yacht sails submitted to a harmonic pitching motion is numerically investigated to address both issues of aerodynamic unsteadiness and structural deformation. The model ...
Numerical study of a Flexible Sail Plan submitted to pitching : Hysteresis phenomenon and effect of rig Adjustments AUGIER, Benoit; HAUVILLE, Frédéric; BOT, Patrick; AUBIN, Nicolas; DURAND, Mathieu (Elsevier, 2014)A numerical investigation of the dynamic Fluid Structure Interaction (FSI) of a yacht sail plan submitted to harmonic pitching is presented to analyse the system's dynamic behaviour and the effects of motion simplifications ...