Originally posted by Yiorgos ...
A venturi may be OK in a glider but it will choke way before M 0.82 (cruise Mach No for A330).
(hint: airflow is accelerated within a venturi)
And icing will also change it's geometry and lead to erroneous readings.
There is no choke point involved. The device is not a venturi in the true sense of the word, but rather a blocked tube passing through a fluid/gas. To my mind the positive pressure rise on one side will be matched by the negative pressure on the other side. The surrounding fluid/gas pressure is the Static and the differences mentioned are the Dynamic pressures. Bernoulli's equation applies in both cases.
Perhaps the name Venturi has been used erroneously, and the title of the post should have been -
"
Airspeed - The Pitot Pressure versus Suction Conundrum"
mm43