If the moment is divided by the dynamic pressure, the area and chord of the airfoil, the result is known as the pitching moment coefficient. How do you calculate pitching moment coefficient? What is negative lift coefficient?Īmong various flow regimes observed, negative values of lift coefficient are found to occur only at low angles of attack, which corresponds to laminar separation without flow transition and without reattachment. Sref is the reference area or the wing area of an aircraft measured in square metres. V defines the velocity of aircraft expressed in m/s. The drag coefficient then expresses the ratio of the drag force to the force produced by the dynamic pressure times the area. Lift is a mechanical aerodynamic force produced by the motion of the airplane through the air. Lift is generated by every part of the airplane, but most of the lift on a normal airliner is generated by the wings. The drag coefficient Cd is equal to the drag D divided by the quantity: density r times half the velocity V squared times the reference area A. Lift is the force that directly opposes the weight of an airplane and holds the airplane in the air.