Induced Drag Calculator
Calculate the induced drag coefficient and force from lift coefficient, aspect ratio, and Oswald efficiency factor.
Induced Drag Coefficient (CDi)
0.00936
Induced Drag Coefficient (CDi) vs Lift Coefficient (CL)
Formule
## Induced Drag Induced drag is the aerodynamic penalty of generating lift. It arises because the wing creates trailing vortices that tilt the local flow downward, effectively rotating the lift vector backward. ### Formula **CDi = CL² / (pi × e × AR)** where CL is the lift coefficient, e is the Oswald span efficiency (typically 0.7 to 0.9), and AR is the aspect ratio. Induced drag dominates at low speeds and high CL, which is why it is critical during takeoff and climb.
Exemple Résolu
A wing with CL=0.5, AR=10, e=0.85, at q=5000 Pa with S=100 m².
- 01CDi = 0.5² / (pi × 0.85 × 10)
- 02CDi = 0.25 / (26.704) = 0.00936
- 03Di = 0.00936 × 5000 × 100 = 4681 N
Questions Fréquentes
What is the Oswald efficiency factor?
The Oswald factor e accounts for the non-elliptical lift distribution. A perfect elliptical wing has e = 1. Real wings with taper, twist, and fuselage interference have e between 0.7 and 0.9.
How can induced drag be reduced?
Increasing aspect ratio is the primary method. Winglets, raked wingtips, and optimizing the lift distribution toward elliptical also help. Reducing weight (and therefore CL) also reduces induced drag.
At what speed is induced drag highest?
Induced drag is highest at low speed because the aircraft must fly at a higher CL to maintain lift. Since CDi scales with CL², slow flight dramatically increases induced drag.
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