1. The problem statement, all variables and given/known data While I was learning about drag and lift on airfloils, I imagined a special airfoil which is fixed at a certain elevation and cannot move vertically (y axis) but can be rotated around its axis (z). Let's assume the direction of the flow to be the x axis. I try to predict the dynamic behaviour of the airfoil after being subjected to a moving fluid. How does the angle of the airfoil change with time when it is subjected to a one dimensional constant velocity flow at x direction. 2. Relevant equations The second question: What is the effect of increasing flow velocity on the angle of airfoil? 3. The attempt at a solution In the case of constant velocity flow, I know that the airfoil tries to reach an equilibrium angle. One equilibrium angle can be the one, at which the velocity of the fluid at the top and bottom of the airfoil are equal. So there will be no driving force for rotation. But right after we apply an angle of attack, pressure difference of two sides of the airfoil causes a clockwise rotation. This will continue until stall is occurred. What happens next? Does the airfoil ever reach a steady state or it continues to rotate?