Wind-tunnel pressure measurements on model-scale rigid downwind sails
TypeArticles dans des revues avec comité de lecture
This paper describes an experiment that was carried out in the Twisted Flow Wind Tunnel at The University of Auckland to measure a detailed set of pressure distributions on a rigid 1/15th scale model of a modern asymmetric spinnaker. It was observed that the pressures varied considerably up the height of the spinnaker. The fine resolution of pressure taps allowed the extent of leading edge separation bubble, pressure recovery region, and effect of sail curvature to be observed quite clearly. It was found that the shape of the pressure distributions could be understood in terms of conventional aerodynamic theory. The sail performed best at an apparent wind angle of about 55°, which is its design angle, and the effect of heel was more pronounced near the head than the foot. Analysis of pressure time histories allows the large scale vortex shedding to be detected in the separation region, with a Strouhal number in the range 0.1 – 0.3, based on local sail chord length.
Files in this item
Showing items related by title, author, creator and subject.
Experimental Investigation of Asymmetric Spinnaker Aerodynamics Using Pressure and Sail Shape Measurements MOTTA, Dario; FLAY, Richard G.J.; RICHARDS, P.J.; LE PELLEY, David; DEPARDAY, Julien; BOT, Patrick (Elsevier, 2014)An innovative method combining simultaneous on-water pressure and sail shape measurements for determining aerodynamic forces produced by sails is described and used on Stewart 34 and J80 Class yachts flying asymmetric ...
AUBIN, Nicolas; AUGIER, Benoit; SACHER, Matthieu; BOT, Patrick; HAUVILLE, Frédéric; FLAY, Richard G.J. (SNAME, 2017)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 ( AW = 60°) unheeled ...
Direct measurement of local constitutive relations, at the micrometre scale, in bulk metallic alloys PLANCHER, E; MAURICE, C; FAVIER, V; LOISNARD, D; RUPIN, N; MARIJON, Jean-Baptiste; MICHA, Jean-Sébastien; ROBACH, Odile; CASTELNAU, Olivier; BOSSO, E; STODOLNA, J; PETIT, J (International Union of Crystallography, 2017)Multiscale models involving crystal plasticity are essential to predict the elastoplastic behavior of structural materials with respect to their microstructure. However, those models are often limited by a poor knowledge ...
HEKTOR, Johan; MARIJON, Jean-Baptiste; RISTINMAA, Matti; HALL, Stephen A.; HALLBERG, Håkan; SRINIVASAN, Iyengar; MICHA, Jean-Sébastien; ROBACH, Odile; GRENNERAT, Fanny; CASTELNAU, Olivier (Elsevier, 2018)We have used Differential Aperture X-ray Microscopy (DAXM) to measure grain orientations and deviatoric elastic strains in 3D around a tin whisker. The results show strain gradients through the depth of the tin coating, ...
Design and manufacturing interface modelling for manufacturing processes selection and knowledge synthesis in design SKANDER, Achraf; ROUCOULES, Lionel; KLEIN MEYER, Jean-Sébastien (Springer, 2008)The research results presented in this paper are related to the specification of a method and models that tackle the problem of manufacturing processes selection and the integration, as soon as possible, of their constraints ...