# Why stall on 2D faster than 3D?

1. why cl on 2D is better than 3D. and why cl 2D stall faster than 3D?

2. what happens when CP continues to move forward on the wing. and what happens when CP continues to move forward on the elevator.

• – Peter Kämpf Oct 4 '17 at 19:20
• Ade, please be aware that asking multiple questions in the same posts is generally frowned upon. In this case they are quite close to each other, so an answer should be able to cover all your questions, but please try to avoid repeating it. – Federico Oct 5 '17 at 20:40

Stall happens because the flow cannot follow the airfoil. If you have a 3d wing, the pressure difference between the pressure side (below the wing) and the suction side (above the wing) can be reduced due to wing tip vortices —> less lift —> smaller $c_L$. They are generated because of the pressure difference. This will reduce the adverse pressure gradient above the airfoil and hence reduce flow separation. These vortices additionally inject energy into the boundary layer (pushing the air toward the airfoil) such that the flow can better follow the air foil despite the adverse pressure gradient. Hence, stall is later for 3d wings.