International audienceThis paper describes a parametric shape modeler tool for deforming hulls and appendages, with the purpose of being integrated into an automatic shape optimization loop with a CFD solver. The modeler allows generating shapes by controlling the parameters of a twofold parameterization: geometrical – based on a skeleton approach – and architectural – based on the design practice and effects on the object's performance. The resulting forms are relevant and valid thanks to a smoothing term to ensure shape consistency control. Thanks to this approach, architects can directly use a NURBS CAD model in the modeler tool and will obtain variations of the initial design to improve performance without additional work. The methodology developed can be applied to any shape that can be described by a skeleton, e.g. hulls, foils, bulbous bows, but also wind turbines, airships, etc. The skeleton consists of a set of B-Spline curves composed of a generating curve and section curves. The deformation of the shape is performed by changing explicit parameters of the representation or implicit parameters such as architectural parameters. The new shape is obtained by minimizing a distance function between the current parameters and the target's in combination with a smoothing term to assure shape consistency control. Finally, the 3D surface wrapping the skeleton is rebuilt using surface network technics. This paper presents the general methodology and an example of application to a bulbous bow on a fishing trawler, with RANSE CFD computations to determine the best design
