Lift Coefficient Calculator Formula
Understand the math behind the lift coefficient calculator. Each variable explained with a worked example.
Formulas Used
Dynamic Pressure
dynamic_press = 0.5 * air_density * pow(velocity, 2)Lift Coefficient (CL)
cl = lift_force / (0.5 * air_density * pow(velocity, 2) * wing_area)Variables
| Variable | Description | Default |
|---|---|---|
lift_force | Lift Force (L)(N) | 50000 |
air_density | Air Density (rho)(kg/m³) | 1.225 |
velocity | Airspeed (V)(m/s) | 70 |
wing_area | Wing Reference Area (S)(m²) | 30 |
How It Works
Understanding the Lift Coefficient
The lift coefficient (CL) is a dimensionless number that captures how effectively a wing generates lift relative to the dynamic pressure and its planform area.
Formula
CL = L / (q * S) = L / (0.5 * rho * V² * S)
where L is the total lift force, rho is the freestream air density, V is the true airspeed, and S is the wing reference area. Typical CL values for cruise flight range from 0.3 to 0.6, while maximum CL at landing with flaps can reach 2.0 or more.
Worked Example
An aircraft at sea level generates 50 kN of lift at 70 m/s with a 30 m² wing.
lift_force = 50000air_density = 1.225velocity = 70wing_area = 30
- 01Dynamic pressure q = 0.5 × 1.225 × 70² = 0.5 × 1.225 × 4900 = 3001.25 Pa
- 02CL = 50000 / (3001.25 × 30)
- 03CL = 50000 / 90037.5 = 0.5554
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