In the lift equation, what does Cl represent?

In the lift equation, what does Cl represent?

• A. Lift coefficient
• B. Drag coefficient
• C. Aspect ratio
• D. Jet velocity

Answer: (B)

Cl represents the lift coefficient, a dimensionless number that quantifies how effectively a wing generates lift at a given angle of attack and airfoil shape. In the lift equation L = 0.5 ρ V² S Cl, lift (L) scales with dynamic pressure (0.5 ρ V²) and reference area (S), with Cl capturing the aerodynamic response of the wing—how lift changes as the wing’s geometry and flow conditions change. Cl is influenced by the angle of attack, airfoil camber, and Reynolds number, and it is the term that differentiates one wing or condition from another in terms of lift production. The other options aren’t correct for Cl: the drag coefficient is Cd, not Cl; the aspect ratio is a geometric parameter of the wing, not a coefficient; and jet velocity is a velocity term, not a dimensionless lift coefficient.

Cl represents the lift coefficient, a dimensionless number that quantifies how effectively a wing generates lift at a given angle of attack and airfoil shape. In the lift equation L = 0.5 ρ V² S Cl, lift (L) scales with dynamic pressure (0.5 ρ V²) and reference area (S), with Cl capturing the aerodynamic response of the wing—how lift changes as the wing’s geometry and flow conditions change. Cl is influenced by the angle of attack, airfoil camber, and Reynolds number, and it is the term that differentiates one wing or condition from another in terms of lift production.

The other options aren’t correct for Cl: the drag coefficient is Cd, not Cl; the aspect ratio is a geometric parameter of the wing, not a coefficient; and jet velocity is a velocity term, not a dimensionless lift coefficient.