quattro digest, Vol 1 #4654 - Correction for - Confused about synthetic gear oil-

[Huw Powell]

> Since we are humans, whom are (hopefully) above room temp,
> we experience the quicker cooling than normal, so we feel as
> if the air were colder, thus called the windchill effect. Also note,
> a warm shut off engine will cool more rapidly to the air temp
> if the wind is sufficiently fast. Thus, windchill is NOT limited
> to humans, but could be determined for the car by comparing
> the cooling rate in the wind to cooling rate in still air. Find the
> still air temp that would cool the engine as rapidly as the windy
> air, and that would be the "wind chill" effect for the engine.

It's actually a subjective-data based calculation.

Since we humans are not only warmer than ambient, we keep trying to stay
that way, it's harder on us than, say, an engine block.

We lose heat *faster* in the wind, and so we have to replenish it faster
and it *feels* colder.  A bunch of studies determined a way to correlate
actual temperature and windspeed to come up with the "subjective"
temperature, or temp with wind-chill factor.

It will vary for other warm blooded critters depending on their species
adaptation to cold (ie fat layers, thick coat, how cold they can let
their skin get, etc.)

It doesn't affect inert objects, they will simply get to a state of
equilibrium with the ambient actual temp (some things stay slightly
wamer, some colder, I believe - though that might just be to the
subjective warm-blooded "touch").  Once they get to ambient, airspeed
won't make them any colder.

--
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/