Lift-to-Drag Ratio
Definition
A physical design concept defining how aerodynamic forces and structural behavior are modeled, tested, and managed in flight or vehicle applications. It governs performance prediction, load sizing, and durability assessment using analysis and test evidence. It does not provide acceptable performance without appropriate design margins and validated models for the intended operating envelope.
Lift-to-Drag Ratio
Definition
The dimensionless ratio of lift to drag for a vehicle, airfoil or aerodynamic element, defined as L/D = Lift / Drag when forces are used or commonly approximated as L/D = C_L / C_D when the same reference area is used for both coefficients; it quantifies instantaneous aerodynamic efficiency in steady flight conditions.