Feature 1 | Yacht Design anD construction
New approach to VPP
Kevin Cudby discusses his part in Jérémie Raymond’s PhD project on the
study of potential design tools for the keelboats of the future. The project
focuses on planing phenomena, an important topic for Groupe Finot, who
financed the project.
raymond’s systematic hull series was based on recent open 60 hulls from groupe Finot, such as Yann elies’s Generali, photographed off
Port-la-Forêt, France in october 2008 (credit: Jean-Marie Liot/DPPi, courtesy Vendée globe).
G
roupe Finot has designed the do not cover planing speeds; and that sizeable chunk of the overall design and
winner of every Vendée Globe current theories of planing hull design construction cost.
except the 2008/2009 edition, in were developed for powerboats, which do Raymond set out to develop a simpler
which its fastest ‘Open 60’ finished second not heel, and which operate in a narrow and less expensive design tool for
behind a design from the USA. According range of speeds. Offshore racing yachts planing yacht hulls. It would be based
to Finot, there is a dearth of knowledge sail upwind at heel angles of at least 30 on information drawn from a systematic
about the influence of hull shape on the degrees, and they are expected to make series of hulls. The software would
performance of planing sailboats such effective use of winds so light they barely estimate the performance of a new hull
as Open 60s, forcing designers to rely make headway. Further complicating shape by interpolating from the known
on intuition. Each generation is lighter the problem, they are driven by a behaviour of several related hulls.
and more powerful than its predecessors, power-plant that varies continually, and The modern planing keelboat has
which implies previous experience may which often generates more side-force evolved a unique shape that seems
not be relevant to new designs. In the than forward thrust. It is no wonder that well-adapted to its role. Beyond the fact
introduction to his PhD report, Raymond the development of a new-generation that they are sharp at one end and blunt
points out that existing design tools such racing yacht usually requires a detailed at the other, the latest Open 60 hulls are
as velocity performance prediction (VPP) tank testing campaign that consumes a nothing like typical cruiser-racer hulls,
26 Ship & Boat International March/April 2010
SBI_MarApr10_p26-27-28.indd 26 26/02/2010 12:22:20
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