Lift Coefficient formula |
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| \( C_l \;=\; \dfrac{ 2 \cdot L }{ \rho \cdot v^2 \cdot A }\) | ||
| Symbol | English | Metric |
| \( C_l \) = Lift Coefficient | \( dimensionless \) | \( dimensionless \) |
| \( L \) = Lift Force | \( lbf \) | \(N\) |
| \( \rho \) (Greek symbol rho) = Air Density | \(lbm \;/\; ft^3\) | \(kg \;/\; m^3\) |
| \( v \) = Air Velocity Related to Wing | \(ft \;/\; sec\) | \(m \;/\; sec\) |
| \( A \) = Lift Surface Area | \( ft^2 \) | \( m^2 \) |
Lift coefficient, abbreviated as \(C_l\), a dimensionless number, normally used in aerodynamics to quantify the lift generated by an airfoil, wing, or other aerodynamic body as it moves through a fluid, typically air. It's an essential parameter in aircraft and aerodynamics analysis, providing insights into the lift producing characteristics of different shapes and configurations. The lifting body can be a foil or a complete foil bearing body such as a fixed wing aircraft.
The lift coefficient is used to normalize the lift force by the dynamic pressure and the reference area. This normalization allows for direct comparison of lift characteristics across different airfoil shapes, sizes, and flow conditions. Aircraft designers and engineers use lift coefficients to optimize the performance of wings and airfoils for specific applications, such as minimizing drag, maximizing lift, and ensuring stable flight characteristics across a range of conditions.
Key Points about Lift Coefficient
- It measures how efficiently an airfoil generates lift, allowing comparison across different shapes, sizes, and conditions.
- Lift coefficient increases linearly with the angle of attack up to a critical angle, beyond which stall occurs, and lift drops sharply.
- The lift coefficient varies with airfoil geometry (camber, thickness), affecting performance characteristics.
- Influenced by factors like airspeed, air density, and Reynolds number.
- The maximum lift coefficient indicates the point of maximum liftbefore stall, critical for determining flight speed.
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Used in aircraft design, performance prediction, and stability analysis to optimize lift-to-drag ratios and ensure safe flight.
