I think if we look at the data provided from this link
http://www.fishcreekflyingclub.com/safety/carbice/
there is something to be learned and it all makes sense. Most of the time there
is icing it involved a delta p in the throttle assembly. There is less pressure
on the engine side than the atmosphere side. The closer that the engine is to
atmospheric there should be a lot less chance as there is no delta p to and no
pressure drop to cause further cooling. I would suspect very strongly that at a
typical 1" of mercury pressure drop at WOT that it is pretty hard to ice the
intake under anything that looks like a normal dew point and temperature. If you
look at the graph most if not 90% of the icing section is under the cruise or
glide mode of operation. That is when the engine is not loaded as much and the
throttles are pulled back from WOT. I am not a pilot but would you use carb heat
on take off as that is what we are doing.. A long high speed taxi. The last 10%
of possible icing conditions are in some pretty rare circumstances. The graph i
would like to see is carb icing at a delta P in the throttle that is
representative of WOT at various temps and dew points.
Dave
Elon Ormsby wrote:
>
<snip>
>
> So here is the fundamental problem. Anytime you cool the incoming air down
> to (or below) the dew point you are going to get icing in the part of the
> air passages where it is slightly cooler. I am not worried about the
> throttle plates (or Dave's trick slide valves) because if, designed right,
> all of the condensation (or icing) would take place somewhere else. Only
> ambient, or cool "DRY" air should arrive at the injectors or butterflies.
> Since a drag car only sees full CFM for 6-8 seconds there is little time
> for icing. But a "full-pull" LSR has a problem. Since the dew point
> changes daily, keeping temps "slightly" above it would create a tuning
> nightmare. So how do you prevent ice from clogging up the air passages? I
> realize sizes will depend on application but do all intercoolers run temps
> "significantly" ABOVE the dew point? Does anybody have any design ideas or
> drawings? -Elon
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