4 ms·

The Coanda effect. Here's Jef Raskin's essay explaining it: http://web.archive.org/web/20070928072421/http://jef.raskincenter.org/published/coanda_effect.html

The Coanda effect. Here's Jef Raskin's essay explaining it: http://web.archive.org/web/20070928072421/http://jef.raskincenter.org/published/coanda_effect.html http://web.archive.org/web/20070928072421/http://jef.raskinc...

hristov 16y ago
This cannot be the Coanada effect because the airflow leaving the wing is completely horizontal. If the Coanada effect was present the air travelling over the top surface of the wing would leave the wing at a downwards angle and that would cause lift.
- Rhapso 16y ago
  and this is why the picture is wrong.
- aufreak3 16y ago
  If you want to satisfactorily explain this to a school kid, it seems like the two most significant factors are a) the angle of attack during take-off - like packing the air under the wing while creating a vacuum above it and b) the curvature taking over the job of "vacuum creation" during steady flight. A flat-wing plane with its wings slicing the air won't have any lift in steady flight. The only way for such a wing to get lift is to use some angle of attack. The lift on a curved wing is enough to support its weight when flying fast, but too subtle to literally lift the plane way up starting from lower speeds as on the ground. Does that about capture the essence of it? Invoking the Coanda effect seems somewhat unnecessary. For example, if you have a wing fitted with zillions of tiny holes through which a small amount of air is being constantly ejected (to counteract the Coanda effect), it still seems (in my mind) possible for the wing to get lift using the angle of attack and curvature.
  - aufreak3 16y ago
    .. and that upside down flight needs flaps on the wings.
- araneae 16y ago
  You're wrong for the right reasons. This would only be a counter-example to the Coanada effect if the xkcd diagram was a correct example of lift. The diagram in this comic would actually produce zero lift, see: http://www.amasci.com/miscon/miscon4.html#wing http://www.amasci.com/miscon/miscon4.html#wing

hristov 16y ago

This cannot be the Coanada effect because the airflow leaving the wing is completely horizontal. If the Coanada effect was present the air travelling over the top surface of the wing would leave the wing at a downwards angle and that would cause lift.

Rhapso 16y ago
and this is why the picture is wrong.
aufreak3 16y ago
If you want to satisfactorily explain this to a school kid, it seems like the two most significant factors are a) the angle of attack during take-off - like packing the air under the wing while creating a vacuum above it and b) the curvature taking over the job of "vacuum creation" during steady flight. A flat-wing plane with its wings slicing the air won't have any lift in steady flight. The only way for such a wing to get lift is to use some angle of attack. The lift on a curved wing is enough to support its weight when flying fast, but too subtle to literally lift the plane way up starting from lower speeds as on the ground. Does that about capture the essence of it? Invoking the Coanda effect seems somewhat unnecessary. For example, if you have a wing fitted with zillions of tiny holes through which a small amount of air is being constantly ejected (to counteract the Coanda effect), it still seems (in my mind) possible for the wing to get lift using the angle of attack and curvature.
- aufreak3 16y ago
  .. and that upside down flight needs flaps on the wings.
araneae 16y ago
You're wrong for the right reasons. This would only be a counter-example to the Coanada effect if the xkcd diagram was a correct example of lift. The diagram in this comic would actually produce zero lift, see: http://www.amasci.com/miscon/miscon4.html#wing http://www.amasci.com/miscon/miscon4.html#wing