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RE: Power Output
Todd,
The basic equation is PV = nRT.
n = mass/molewt, so PV = mass*R*t/Molewt
Density = mass/volume = P*molewt/RT
The volume of the cylinder (within limits) is fixed. The molewt is fixed.
R is a constant. Therefore the only independent variables are P and T.
What we want is greater mass of air which allows burning a greater amount
of fuel which produces more power. The equation shows the higher pressure
and lower temperature favor this condition.
At 05:55 PM 4/1/98 -0800, you wrote:
>
>1.8 Bar is 1.8 bar no matter what the temp. At higher temps, the turbo
>has to work harder to get 1.8 bar because the barometric pressure of the
>outside air is lower.
>
>I guess the old anology, "which is lighter, one pound of feathers or one
>pound of lead". Well, neither, they are both one pound. But the pound
>of feathers will take up WAY more space.
>
>That make sense? I am not the say all, know all, so I may be off a little
>on this but if my Flight lessens taught me anything about the way air
>works, I should be right.
>
>I think that the volume of air might be different though. Hence, people
>use intercoolers to force more air in. Cools the air, makes it more
>dense, so more enters engine but at same pressure. That might be the
>power difference you are feeling. I know airplanes have huge differences
>in top speed and climb rate at higher temperatures. Cool mornings or
>winter is the best time to fly an underpowered plane. Much smotter to
>BTW.
>
> Anyhow, hope that was of help. L8R
___
Bob
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