Quote:
Originally Posted by Faster
... and today rudders are back to "rounded" elliptical shapes, I believe to minimize vortice losses off the square tip. (harking back to the Spitfire fighter's wing design) btw- strictly armchair talking here....
Rounding off the tip of your rudder will cost you effective area. It may avoid some of the cavitation you feel at extreme conditions, but the loss of maneuverability in more typical conditions may not be worth it.
You do need a real designer's take on this.
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I have the other armchair (and thanks for a comfortable design decision)...
If there is one thing is mis-understood is the hydro-fluid dynamics are not necessarily correlated to air - dynamics...
Its the density and the fact that air and water have very differnet effect. For instance water is elliptical in shape..and temps actually elognstate (sp) water molecules - example - fill a glass with water and then add drop by drop... you will notice that the water will bend and statically hold to the point the overhang goes over the rim of the glass...
The newer designs of rudders are longer - and have less width and are rounded - some actually equipped with fins to create vortexes...inj the belief those vortices disturb the friction capability of water (ref the glass example above)...
Under sail - yes - you will get better perf - handling wise at lower rpms - nothing out there substantiates that it actually has an effect and is all hearsay at this point...