Does lift generation create a vacuum over an airfoil? [duplicate]

According to Bernoulli’s principle, airflow speeds up over an airfoil which decreases the pressure, and I read somewhere that when airflow speeds up over an airfoil, this creates a vacuum. Is this statement true?

How would a vacuum above an airfoil be different from airflow separation?

• See Chapter 3 here av8n.com/how/#contents. True, there may be some vacuum formed to suck the plane up in the air, but I think that is more than overcom by the air being pushed down by the wing, and conversely the air pushing the wing up in elevation. And of course, the many related topics over on the right. – CrossRoads Nov 13 '18 at 16:09
• @CrossRoads Okay now if there is a vacuum over the wing, wouldn’t be the same as airflown separation ? – Ismail El-Shaarawy Nov 13 '18 at 16:48
• See 3.7 and Figure 3.11. The low pressure (vacuum) area can be seen to be pretty small: The second type of stall-warning device (used on the Cessna 152, 172, and some others [my 177], not including the 182) operates on a different principle. It is sensitive to suction at the surface rather than flow along the surface. It is positioned just below the leading edge of the wing, as indicated in the right panel of figure 3.11. – CrossRoads Nov 13 '18 at 16:56
• At low angles of attack, the leading edge is a low-velocity, high-pressure region; at high angles of attack it becomes a high-velocity, low-pressure region. When the low-pressure region extends far enough down around the leading edge, it will suck air out of the opening. The air flows through a harmonica reed, producing an audible warning. – CrossRoads Nov 13 '18 at 16:57
• I'm just using "partial vacuum" as shorthand for lower pressure in one spot than in an adjacent one. Probably not good as a scientific or engineering term. – John K Nov 13 '18 at 19:52