Aircraft Structure and Design PDF

AIRCRAFT STRUCTURE AND DESIGN Item Effect of Increased Wing Aerodynamic Twist Sweep on Item  Angle between zero-lift angle of an airfoil Forward None Aft and the zero-lift...

AIRCRAFT STRUCTURE AND DESIGN Item Effect of Increased Wing Aerodynamic Twist Sweep on Item  Angle between zero-lift angle of an airfoil Forward None Aft and the zero-lift angle of the root airfoil Lift-Curve Slope Low High Low  If identical airfoil is used root to tip, Pitch Attitude in Low High Low High aerodynamic twist is the same as the Speed, Level Flight geometric twist Ride through Good Poor Good Turbulence Asymmetric Stall Best Good Poor Item Effect of Twist angle on item Lateral Control at Stall Best Good Poor Large Small Compressibility Drag Low High Low Induced Drag High Small Wing Weight Highest Low High Tip Stall Good Poor Wing Weight Mildly Lower Mildly Higher TAPER RATIO  Ratio between the tip chord and the WING INCIDENCE centerline tip chord  The pitch angle of the wing with respect  Affects the distribution of lift along the to the fuselage span of the wing  Minimizes drag at some operating  More taper, lesser the weight conditions, usually cruise  Less taper means more fuel volume Item Effect of Wing Incidence on item Item Effect of Taper Ratio on Large Small Item Cruise Drag High Small High Low Cockpit Good Watch out Wing Weight High Low Visibility Tip Stall Good Poor Landing Watch out No problem Wing Fuel Volume Good Poor Attitude TWIST  Used to prevent tip stall and to revise the lift distribution to approximate an ellipse  Large amount of twist should be avoided Geometric Twist DIHEDRAL  Actual change in airfoil angle of  Angle of the wing with respect to the incidence, usually measured with respect horizontal when seen from the front to the root airfoil  Tends to roll an aircraft whenever it is banked  10° of sweep provides about 1° of Linear Twist effective dihedral  Twist angle changes in proportion to the distance from the root airfoil 4 MMTB