C-Class Catamaran Wing Performance Optimisation

Researcher: Nils Haack

Supervisor(s): Dr. R Prosser
Start Date: September 2009 End Date: January 2011
Keywords: CFD, RANS, wingsail, C-Class, catamaran

Overall Research Aim

The aim of this study is to generate aerodynamic data required by the VPP. More precisely the lift and drag polars for the wing profile sought in typical sailing configurations. Furthermore, the effect of the gap size between the main wing and the flap on the polar plots is a key outcome.

Finally, visualisation of the flow around the root of the wing will be provided: this is intended to aid quantitative judgement on the effect on lift produced by a flying hull.

Research Progress


This research is concerned with the wing of the C-Class catamaran of Team Invictus, see figure 1. The current wing is a reverse engineered design of a previous successful C-Class catamaran; a wing with an external flap. This design was modified at the trailing edge of the main wing with a morphing trailing edge. The modifications were done on the basis of engineering judgments. Due to budget restrictions expensive wind tunnel test were not conducted. Thus results of this study are not compared to wind tunnel tests. Within the limits of this degree lift and drag polars (in this case a polar is the lift coefficient Cl or drag coefficient Cd plotted versus the angle of attack) of the wing profile were produced. This was done by the use of CFD (Computational Fluid Dynamics). The standard k − ε turbulence model was concluded to be sufficient for this task. It was found that a 2% (of main wing chord) gap setting between the trailing edge of the main wing section and the flap is more efficient than the previously used 3%. Further more a flow visualisation study was conducted around the entire wing. The visualisation indicates that the boat has an effect on the pressure distribution on the wing and that more detailed analysis is required to quantify the effects of the gap between the root of the wing and the boat.
Fig 1: C-Class catamaran of Team Invictus, 'Invictus II'

Last Modification: r6 - 2011-01-27 - 14:48:51 - NilsHaack

Current Tags:
create new tag
, view all tags
Topic revision: r6 - 2011-01-27 - 14:48:51 - NilsHaack

Computational Fluid Dynamics and Turbulence Mechanics
@ the University of Manchester
Copyright & by the contributing authors. Unless noted otherwise, all material on this web site is the property of the contributing authors.