https://www.intmaritimeengineering.org/index.php/ijme <p>The International Journal of Maritime Engineering (IJME) provides a forum for the reporting and discussion on technical and scientific issues associated with the design and construction of marine vessels. Contributions in the form of papers and notes, together with a discussion on published papers are welcomed.</p> <p>The IJME is published four times a year as the Transactions of The Royal Institution of Naval Architects and is available on subscription to members, and non-members.</p> <p>ISSN: 1479-8751</p> <p> </p> University of Buckingham Press en-US International Journal of Maritime Engineering 1479-8751 https://www.intmaritimeengineering.org/index.php/ijme/article/view/1317 <p>Wind-assisted ships and racing yachts employ highly cambered profiles to maximise performance. However, their complex aerodynamics governed by flow separation remains to be fully understood. Particle image velocimetry (PIV), performed in water tunnels, may lead to breakthroughs, provided fundamental spatial and temporal resolution limitations are overcome. Consequently, force measurements and flow visualisation were undertaken on circular arcs and yacht sails to ascertain the viability of this experimental approach. The results show that (i) a linear blockage correction can be devised; (ii) a blockage-independent critical Reynolds number and critical angle of attack exist; and (iii) a force crisis occurs because of the suppressed relaminarisation of the boundary layer downstream of the leading-edge separation bubble. Ultimately, PIV in water tunnels is shown to be a pertinent methodology. These findings provide novel insights into the aerodynamics of wind-assisted ships and yachts and may contribute to improving their performance by design.</p> Jean-Baptiste Souppez Copyright (c) 2025 International Journal of Maritime Engineering 2025-06-24 2025-06-24 166 A1