Fred,
At high throttle settings, I agree completely - the reason the carb has a venturi is specifically to reduce the pressure.
But, at low throttle settings, the venturi in the carb is not significant enough to cause a large pressure drop (at least, not in a constant-venturi carb as used on most aeroplanes). That is why this type of carb is fitted with additional jets in the vicinity of the butterfly - because, at low throttle settings, the pressure drop caused by the butterfly will be far more significant than the pressure drop through the throat of the carb. And we all know that carb ice is predominantly a problem at low power settings - hence my assertion that the carb's venturi is not significant in causing carb ice.
Am I wrong? If so, why?
FFF
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