Mayf, list:
Not quite that simple, because when you cool the air you also reduce its
pressure
("ideal gas law", Pv = rT). Hugh MacInnes book Turbochargers has a good chapter
on intercoolers, including how to calculate potential gains. Even something on
a
patent-pending freon-refrigerated design (different from the "Rankine cycle" we
usually expect; uses a "jet" compressor, rather than one that is
mechanically-driven. No parasitic engine power loss???)
Good book.
Russ Mack
DrMayf wrote:
> This is a large subject! Efficiencies on intercoolers can be very high, 80%
> or more, but can never lower the exit air temperature less than ambient air
> temperature. In other words, if the air temp is 90 degrees and tyou are 100
> percent efficient then that is a low as you can go. Unless you are using
> water to air or some other heat transfder mechanism like CO2 for the cooling
> media. As to hp gains, losses, I think that horsepower goes up or down as
> air charge density changes. So If you run your motor on a dyno at standard
> conditions and then decided to see what the hp is at B'ville, then just
> ratio the air charge densities (I "think"...this could be dangerous, me
> thinking, that is). For example the air density ratio fro B'ville at
> standard conditions is, again, I think, 0.882 so you would lose about 12
> percent of your horsepower. Conversely, if your air charge density went up,
> then you would gain back that which was lost. I think this is all prety
> calculable (is that a word meaning to be able to calculate?).
>
> mayf
> >
> > Does anybody have figures on hp gains/degree drop etc.?
> > How much temp. drop do you get from a good air/air intercooler? (of
> course that
> > depends on ambient ranges)
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