6DOF behavior of an offshore racing trimaran in an unsteady environment
Résumé
While in recent years the use of hydrofoils has experienced a substantial growth, traditional design tools such as Velocity
Prediction Programs (VPP) have proven inadequate to help architects and engineers with performance trade offs which
now include specific stability issues related to these foils. The quest for performance also demands a better account of the
unsteadiness of the environment in which the offshore yachts evolve.
Time-domain analysis and system-based modeling allow for an improved understanding of the controllability and dynamic
stability of given geometries, enabling to adapt and refine the design. This paper presents such a dynamical unsteady
model, based on the superposition of several loads components, computed from either numerical, empirical or analytical
models. A test case and its results are presented to show the reliability and efficiency of the developed numerical tool, by
comparing response amplitude operators of a reference hull form with experimental and numerical data.
Finally, the paper outlines two 6DOF dynamic simulations of an offshore trimaran. The first case shows a simple bearaway
maneuver and compares two sail tuning strategies, while the second one presents the yacht evolution in unsteady wind
demonstrating how in varying conditions the boat may reach attitudes that widely differ from the steady ones.
Domaines
Sciences de l'ingénieur [physics]
Origine : Fichiers produits par l'(les) auteur(s)