Fliegen-ohne-Stroemung.de / flying-without-flow.eu
Home
Bilder Images
Eigene Videos
Wind
Mehr Beispiele
More examples
Lee-Effect
Propeller
Helicopter
Engine
Rocket
Angle of attack
Flaps
Rudder
Car in the rain
Entwicklung
Development
Impressum
Kontakt/ contact
Fremde Videos
Buchempfehlung
Link zu Facebook

Control surfaces: Aileron, rudder, elevator 

In the description of the effect of control surfaces, no matter whether aileron, rudder, or elevator, I think Bernoulli mostly is "bent". According to Bernoulli the distance for the "flow" is extended by the way directed on the outside. Due to the accelerated "flow" a vacuum shall be created, that then pulls the appropriate control panel in the desired direction.

Please perform the following attempt: Take your car (please not too fast) with open side window and keep the hand (or better a small wooden board) horizontally out of the window. Now you can turn your hand (or board) slightly up or down. You will notice how the hand is pressed strongly up and down and that surely not by the vacuum but by the hand (or board) deflected air mass (Newton), ...like a surfer or windsurfer (with a too small board), only can stay by dynamic lift on the surface of the water!

 

 

Rudder:

It is particularly obvious when facing at a control surface with "load-balance", i.e. a part of the control surface draws exactly to the other side and stands directly in the "air flow". The purpose of such a surface is that the forces needed to deflect the surface is decreased on the actuator or the controls.
According to Bernoulli the effect of rudder should decrease as well (because the length of the rudder the stream lines are speeded up, is shorter), ...but the opposite is the truth! Despite lower steering forces the effect of surface is increased!

SR