Polar Curve Points

081-08-03Pablo Asensio Martínez2026-04-011 min

Drag Polar

A graph of Lift Coefficient ($C_L$) vs Drag Coefficient ($C_D$).

  • Tangent from Origin: The point of maximum Lift-to-Drag Ratio ($L/D_{max}$).
  • Top of the Curve: $C_{Lmax}$ (Stall speed).

Significant Speeds (Thrust Required Curve)

Plotting Drag (Thrust Required) vs Speed ($V$).

  1. Vmd (Minimum Drag Speed): The bottom of the U-shaped curve.

    • Occurs where Parasite Drag = Induced Drag.
    • Speed for Max Range (Jet) and Max Endurance (Prop - approximately).
    • Speed for Best Glide Angle (Max Distance).

  2. Vmp (Minimum Power Speed):

    • Occurs at approximately $0.76 \times V_{MD}$.
    • The point where the product of Drag $\times$ Velocity is minimum.
    • Speed for Max Endurance (Jet) because fuel flow is proportional to thrust $\times$ speed (power).
    • Speed for Minimum Sink Rate in a glide.

  3. Vx (Best Angle of Climb): Speed where Excess Thrust is maximum. Close to $V_{MD}$.

  4. Vy (Best Rate of Climb): Speed where Excess Power is maximum. Higher than $V_x$.