Well, this discussion has the potential to explode into a very large validation research. But such a thing will get beside the point.






The best experimental data I have is Bethwaite and the Miss Nylex C-class design article. Especially the last quantifies the different drag components. Here the wave-making drag (form drag)for the conditions in which the C-class races was given as 15 % while the wetted surface area drag (skin drag) was given as 22 % of the total drag of the whole boat.

To put things in perspective, the drag related to the rig itself was given as 30 %. The daggerboards at 21 %

I still value the C-class designers as the most scientificatlly oriented catamaran designers. It also squares nicely with what is known from other sources like Bethwaite and the design of mono-hulls. The model I described neatly fits all the experiences over a wide range of vessels.

Added to this the F16 experience itself. The F16 concept was developped fully based on the model I presented earlier. As of yet the F16 is doing exactly what it is predicted to be doing by the model and so in that experience I find no counterproof as of yet.

I don't know what kind of model your software is using. I would be interested in finding out what drag it predicts for a long flat plate dragged through the water. Good predictions are to be found for this situation to check the software itself.


Having said all this I spot a contradiction in your statements. You wrote :




First you say it is far from negligible but later you say "there is bugger all in it", implying that indeed it is negligiable !

Please clearify.


Regards,

Wouter


p.s. I'm afraid that I won't be able to discuss everything in detail, I simply don't have the time for that.