NACA Airfoil Simulator | Four-Digit Shapes and Lift

Q: What scale does the Reynolds number input use?

Millions: 3.0 means Re=3×10⁶. Re enters a simplified drag expression; the tool does not solve boundary-layer transition or separation.

Q: Does thin-airfoil theory predict stall?

No. The displayed stall angle and post-stall curve are simplified assumptions added to the model. Do not use them as a real aircraft's operating limits.

Q: Why can thickness change without changing lift?

Before modeled stall, thickness does not directly change the linear lift slope. It does affect shape, drag and the simplified stall model. Compare the relevant output and condition.

Q: Are streamlines and Cp calculated by CFD?

No. The flow and pressure visualizations are simplified, not a numerical Navier–Stokes solution. Real design requires validation at matching Reynolds number, surface condition and angle.

Select NACA airfoil

Maximum camber M (%)

Camber position P (×10%)

Maximum thickness XX (%)

Flow conditions

Angle of Attack α (°)

Re (×10⁶)

×10⁶

Animation

Overlays

Streamlines Cp distribution (airfoil surface color) Lift vector Stall annotation

Preset

Analysis Results

Results

Angle of Attack α (°)

Cp_min (suction peak)

Stagnation point x/c

L/D

α₀ (°)

Stall Angle (°)

CL,max

Airfoil

Lift coefficient Cl vs angle of attack α

Theory & Key Formulas

Pressure Coefficient Cp Distribution

Theory & Key Formulas

$$C_L = 2\pi\,(\alpha - \alpha_{L0}),\qquad C_p = 1-\left(\frac{V}{V_\infty}\right)^2$$

α: angle of attack α_L0: zero-lift angle (due to camber) V: local flow velocity V∞: freestream velocity. Lift-curve slope = 2π/rad ≈ 0.11/°. Flow accelerates over the upper surface (V>V∞→Cp<0=suction), while V=0→Cp=1 at the stagnation point. The Kutta condition makes the flow leave the trailing edge smoothly and determines the circulation.

Questions and answers

What scale does the Reynolds number input use?

Millions: 3.0 means Re=3×10⁶. Re enters a simplified drag expression; the tool does not solve boundary-layer transition or separation.

Does thin-airfoil theory predict stall?

No. The displayed stall angle and post-stall curve are simplified assumptions added to the model. Do not use them as a real aircraft's operating limits.

Why can thickness change without changing lift?

Before modeled stall, thickness does not directly change the linear lift slope. It does affect shape, drag and the simplified stall model. Compare the relevant output and condition.

Are streamlines and Cp calculated by CFD?

No. The flow and pressure visualizations are simplified, not a numerical Navier–Stokes solution. Real design requires validation at matching Reynolds number, surface condition and angle.

NACA Airfoil Simulator | Four-Digit Shapes and Lift

Worked example

Model and scope

Questions and answers

🎬 Watch it in motion

NACA Airfoil Simulator | Four-Digit Shapes and Lift

Worked example

Model and scope

Questions and answers

Related Tools

🎬 Watch it in motion