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Old 04-21-2018, 12:07 AM   #14 (permalink)
Piwoslaw
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Join Date: Oct 2008
Location: Warsaw, Poland
Posts: 3,541

Svietlana II - '13 Peugeot 308SW e-HDI 6sp
90 day: 58.1 mpg (US)
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Quote:
Originally Posted by kach22i View Post
I found something odd, and if all "fluid dynamics" are fair game then explain the advantage of the gap/slot before the movable portion of the rudder.
My 2 guesses:
  1. To increase the flow over the movable part. This may slightly increase drag, but improves the efficiency of the rudder, allowing it to be smaller. And a smaller rudder reduces drag and/or noise.
  2. When the movable part turns to one side, there will be lower pressure on the "back" side, causing additional noise. The gap allows this void to partially fill in, reducing noise.
For a submarine silence is more important than fuel efficiency.
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Piwoslaw's Peugeot 307sw modding thread

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