4 ms·
See my sister comment. The Bernoulli effect explains the pressure differential by way of an above-wing streamline reaching the back of the wing at the same ti
by lowkey 5y ago
See my sister comment. The Bernoulli effect explains the pressure differential by way of an above-wing streamline reaching the back of the wing at the same time as the below wing streamline. Since the upper wing is curved and therefore a longer path the theory claims the pressure differential is caused by the upper streamline traveling faster than the lower streamline.
The problem with this theory is that there is no physical reason why both streamlines must arrive at the back of the wing at the same time - and per experimental verification, in fact they don’t.
- jjk166 5y ago> The Bernoulli effect explains the pressure differential by way of an above-wing streamline reaching the back of the wing at the same time as the below wing streamline. Since the upper wing is curved and therefore a longer path the theory claims the pressure differential is caused by the upper streamline traveling faster than the lower streamline. That's not how the Bernoulli effect explains the pressure differential. The bernoulli explanation is that air builds up in front of the airfoil, creating a high pressure region, while there is a low pressure region created in the wake of the wing. This pressure differential forces accelerates air over the wing. For an asymmetric airfoil, more of this flow is over the top than the bottom, so the airflow over the top is faster, and thus lower pressure, than the airflow under the wing. The "equal time" thing is a pop-science misunderstanding.
- boublepop 5y agoThat is sadly literally how it is explained both in classes and in textbooks. It’s incorrect but it’s how it’s taught which is the root of a lot of misconceptions and why this “explanation” which is not correct keeps living on.