First we need Airfoils • a body (as an airplane wing or propeller blade) designed to provide a desired reaction force when in motion relative to the surrounding air. • This force can come in the form of lift, drag, stability and control.
Definitions • Camber – the curvature of the airfoil • Chord Line – A reference line to go from leading edge to trailing edge • Chord line is used to discuss two angular definitions
Angles • Angle of Attack – the angular difference between the airplanes relative wind and the wings chord line • Angle of Incidence - the angular difference between the longitudinal axis of the airplane and the wings chord line • Pitch Angle – the difference between the longitudinal axis of the airplane and the horizon
Angle of Attack • All factors being equal lift will increase with an increase in angle of attack.
Angle of Attack • Ways to change AoA • Changing pitch • Changing the shape of the airfoil
Lift Adding Devices • Aspect Ratio – The ratio between a wings chord and its span. The larger the aspect ratio the less force needed to create lift. Thus larger aspect ratio requires less thrust. 27:1 Aspect Ratio