Magnus Force Calculator
Estimate lift per unit length due to rotation in a uniform flow (idealized cylinder model).
How to Use This Calculator
Enter fluid and flow values
Provide density ρ and free-stream speed v.
Enter body rotation
Input radius R and angular speed ω of the spinning cylinder.
Calculate L'
Press Calculate to get Magnus lift per unit length.
Formula
L' = ρ · v · Γ, with Γ = 2π R² ω
Where: L' is lift per unit length (N/m), ρ is density, v is speed, Γ is circulation.
Example: ρ=1.225 kg/m³, v=30 m/s, R=0.05 m, ω=200 rad/s ⇒ Γ=3.1416 m²/s, L'≈ 1.225·30·3.1416 ≈ 115.4 N/m.
About Magnus Force Calculator
The Magnus effect creates lift on spinning bodies moving through a fluid. This idealized cylinder model provides a first estimate of lift per unit length via circulation.
When to Use This Calculator
- Sports ball aerodynamics: Estimate spin-induced lift trends.
- Rotating cylinders: Analyze lift generation concepts (e.g., Flettner rotors).
- Education: Demonstrate circulation-lift relationship.
Why Use Our Calculator?
- ✅ Quick: Minimal inputs, instant results.
- ✅ Transparent: Shows formula and example.
- ✅ Educational: Highlights assumptions and scope.
Frequently Asked Questions
Does this account for drag and viscosity?
No. It uses an idealized inviscid model via circulation. Real forces depend on Reynolds number, surface roughness, and separation.
What about spheres instead of cylinders?
The formula given is for a long cylinder. Spheres experience Magnus lift but require empirical or CFD-based correlations.
What is the output unit?
Lift per unit length, in newtons per meter (N/m). Multiply by length for total lift for long cylinders if end effects are negligible.