In a message dated 5/20/02 6:56:27 AM Central Daylight Time, stever@mail.saabnet.com writes:
You may not want to know this, but aspect ratio is defined as the area of the rudder divided by the chord squared. Chord is the width of the rudder, front to back when centered. Area is the area if you viewed the rudder from the side.
Put another way, high aspect rudders are deep and narrow. Low aspect rudders are shallow and fat. Low aspect foils are good at low speeds, whereas high aspect foils shine at higher speeds.
The following examples may be useful for visualization, or at least entertaining.
Let's compare two birds: A mourning dove and a quail. A dove's wings are long and narrow, a high aspect design. Quail wings are short and fat or low aspect. A mourning dove is faster, right? Well, sort of. In anything more than a sprint, the dove will rule-its top end is much higher. But off the line, a quail with its short, high lift wings will bury a dove, and out turn it. It just depends on what sort of race it is. The goal of both birds, however, is the same: don't get et, albeit under different conditions.
Perhaps most importantly, if you start mixing and matching dove and quail parts, you will usually get a mess that doesn't do anything well. An outstanding design integrates and balances all components, something that Montgomeries do very, very well, by all accounts :)
One of these days, one of these days, I'll get to experience a Monty firsthand!
Steve Tyree, P-15 #2098 (that's a West Wight Potter, another delightful boat)