You need to have foils in excess of three times deeper than their cord before you diminish the wave making to levels where it is no longer significant. The wave making is a function of the lift generated not the thickness. Setting the foil deeper reduces wave making but there is then extra drag on the supporting structure.
Also the L/D you are quoting is for 2D flow. It will be much less when you start considering realistic spans able to support tonnes of boat.
It is not easy to get a hydrofoil system with L/D better than 20 overall.
The section shape is more driven by cavitation than the 2D L/D. Unless foil cavitation is accounted for you may as well keep it simple and go for a slender planing hull as these hulls are capable of 20+kts and are simpler.
On 14/12/2014, at 10:06 PM, "cruisingfoiler@yahoo.com.au [harryproa]" <harryproa@yahoogroups.com.au> wrote:
When it comes to Froude effects, I am not overly concerned - but I confess I haven't quantified the effect. The foils are 8.64% and 9.34% thickness respectively, with 3.38 and 3.73% camber. I'm working on the theory that thin foils will exhibit low wave making resistance.
__._,_.___
Posted by: Rick Willoughby <rickwill@bigpond.net.au>
| Reply via web post | • | Reply to sender | • | Reply to group | • | Start a new topic | • | Messages in this topic (24) |
.