Elon, you "snipped" my comment about dew point and temperature being close
together......my point was that carb heat won't help fuel distribution and
ice isn't due to low temperature alone.....oh well.....I guess I didn't
make my point very well....thanks for the excellenct explanation of how it
works though.
Skip
At 03:14 PM 12/4/02 -0800, Elon Ormsby wrote:
>Skip Higginbotham said (snip). . . emergency landing due to broken carb
>heat linkage and one on which the jury is still out......wasn't cold
>outside....about 90 degrees.
>
>A high OAT has very little to do with the potential for carb icing. The
>dew point is far more important. At 100 degrees f a dew point of 50-70 deg
>f will cause icing (with a relative humidity of only 20-40%). Sounds like
>your 90 degree day had a high dew point, a perfect recipe for
>icing. Remember, there is not only an endothermic phase-change taking
>place with the gas but the water vapor phase-change (into condensation,
>necessary for ice to form) is also endothermic. The combination of the two
>(and the manifold pressure drop) can lower the temp at the carb venturi to
>below zero f!! -Elon
/// unsubscribe/change address requests to majordomo@autox.team.net or try
/// http://www.team.net/mailman/listinfo
/// Archives at http://www.team.net/archive/land-speed
/// what is needed. It isn't that difficult, folks.
|