Figure 1. Aerodynamics: The science of the air flow around as well as the forces and moments acting on a structure in a moving airstream Major aerodynamic forces on aircraft: • Lift = L • Drag = D • Pitching Moment = M • Thrust = T • Weight = W Steady level flight: Lift = Weight Thrust = Drag M = 0
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Major aerodynamic forces on aircraft: Lift = L Drag = D Pitching Moment = M Thrust = T Weight = W
Figure 1. Aerodynamics: The science of the air flow around as well as the forces and moments acting on a structure in a moving airstream. Major aerodynamic forces on aircraft: Lift = L Drag = D Pitching Moment = M Thrust = T Weight = W. Steady level flight: Lift = Weight - PowerPoint PPT Presentation
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Figure 1. Aerodynamics: The science of the air flow around as well as the forces and moments acting on a structure in a moving airstream
Major aerodynamic forces on aircraft:
• Lift = L• Drag = D• Pitching Moment = M• Thrust = T• Weight = W
Steady level flight:
Lift = Weight
Thrust = Drag
M = 0
Airfoil Geometry
• b = span
• c = chord
• S = planform area
• Aspect Ratio = b2/S = A
Sail Geometry
Camber = t/c
Aspect Ratio: A = b2/SA
SA = Sail Area
Forces on Wing & SailWing
Sail
L = Lift
D = Drag
R = Resultant
V = Relative Wind
Forces on a Sailboat
A 6-Metre yacht
Equilibrium of forces in the close-hauled sailing condition, Vt = 12 knots
LWL = 23.5 ft
Beam = 6.5 ft
Draft = 5.4 ft
Displacement = 94 lb
Sail Area = 600 sq ft
Lateral Area (hull) = 70 sq ft
Angle of heel = 20°
Basic properties of the atmosphere required for sailing or winged flight
Density (function of p & T) Viscosity
If air had density but no viscosity Balloon flight is possible No sailing or winged fight is possible Early inviscid theory predicts no lift