Talador
See inserts.
Rick
Any supercavitating foil has "horrible" lift to drag - cannot be avoided. He spent a lot of effort to get it only horrible. In fact they got it to the horrible stage by ventilating the trailing edge. Here ventillation actually reduces drag.
You know that the rotation creates drag too?
Not measurable.
Not just the form shape drag.
Rotation give attached flow, which lowers drag.
"I point out that appendages penetrating the surface cause unnecessary drag and you point to a 65 knot proa. But please don't take my word for it, lets see what the designer has to say about that appendage."VSR2 is designed to have enough power and efficiency to be able to drag a truly horrible plough-like cavitating foil through the water at over 60 knots. Anything better than ‘truly horrible’ will result in either higher speeds or greater efficiency in lighter winds."
High speed surface piercing propellers are not very efficient but they are faster than conventional set up because they eliminate other appendages such as shafts.
Your appendage drag is truly horrible too, but for some reason I don't think you have the power to overcome the drag like the Vesta's Rocket does.
You cannot possibly know this. You come up with any alternative and I guarantee it will be higher drag than I have.
Your conclusion is correct but understanding still lacking.I need to add that at your target SLR of 1 to 1.3, the extra drag of the hard chines, extra wetted area, concave aft hull, non aerodynamic appendages projecting into the water, etc. probably don't add up to much, they may not even be measurable. It is only when you get past displacement boat speeds that they matter and for what you are trying to do I would think that aiming at a SLR of 1 is the way to go. You are right, nothing I have suggested would be of any value to you.
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Posted by: Rick Willoughby <rickwill@bigpond.net.au>
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