Live aerodynamics engine

Airfoil Explorer.
Every wing here is being computed, right now.

A NACA 4-digit airfoil, its 3D wing, and its full aerodynamic polars — solved live in your browser from thin-airfoil theory and cross-checked against XFoil. Not a screenshot of one.

GEOMETRY + AERO · L1 COMPUTING
Profile2412
Angle of attack+5.0°
Cl — lift
Cd — drag
L/D — efficiency
Full 3D control · live polars · XFoil comparison · airfoil search
Free · no signup · runs entirely in your browser
01
How the engine works
Four systems run every time a slider moves — geometry, aerodynamics, visualization and comparison, all client-side.
01 Geometry engine
Real NACA 4-digit surfaces
Thickness, camber and camber-position combine into a true NACA 4-digit surface via the standard 4-digit equations with a sharp trailing edge — computed live, not a lookup of pre-rendered shapes.
02 Aerodynamics engine
Thin-airfoil theory + XFoil
Lift, drag and moment from thin-airfoil theory — numerically-integrated zero-lift angle and quarter-chord moment, Glauert thickness and Prandtl–Glauert compressibility corrections, Reynolds-scaled drag.
03 Visualization engine
Live 3D wing, orbit & zoom
A full Three.js scene renders the wing in 3D with airflow that bends with camber and tilts with angle of attack — orbit, zoom, all rendered in your browser.
04 Comparison engine
Compare & check fidelity
Overlay two airfoils, or switch to fidelity mode to plot thin-airfoil theory vs XFoil vs your own CFD against each other with a computed error table.
02
This chart is live
Nothing below is an image. The lift curve is solved by the same engine the simulator uses — pick a profile and watch it recompute, point by point.
SOLVED IN-BROWSER
NACA 2412general-aviation workhorse
Choose a profile
2412
0012
4412
6412
2415
0009
Thin-airfoil theory (L1)
Post-stall (approximate)
Stall point
In the simulator's fidelity mode, real XFoil data is overlaid directly on top of this curve.
03
Built to be trusted
Real equations, validated against published XFoil data — with honest uncertainty on every number.
01

Real geometry

True NACA 4-digit equations, computed live — not a table of pre-rendered shapes.

02

Real physics

Thin-airfoil theory with Glauert & Prandtl–Glauert corrections and Reynolds-scaled drag.

03

Validated vs XFoil

Nine reference profiles cross-checked against precomputed XFoil polars at Re = 1×10⁶.

04

Honest error bounds

Every coefficient carries an uncertainty band; post-stall values are flagged as approximate.

05

Real-time

Every slider redraws the wing, the airflow and all four polar charts instantly.

06

Free & open

No paywall, no signup. Runs entirely client-side. Export your data any time.

04
Who it's for
Anyone building intuition for how a wing behaves — before spinning up a full CFD pipeline.

Aerospace & engineering students

Build intuition for camber, thickness and stall before touching XFoil or a CFD suite.

RC & UAV designers

Compare candidate airfoils for a build without a full simulation pipeline.

Wind-turbine & hobby builders

Explore how thickness and camber trade lift against drag at low speed.

Educators & self-learners

A visual, interactive companion to thin-airfoil theory — works in any browser.

Jump straight in — no signup.

NACA / 2412 · Airfoil Explorer

A:2412 B: DASHED = B
NACA 2412  ·  α =
DRAG TO ORBIT  ·  SCROLL TO ZOOM
Cross-section
Thickness12% c
Max camber2% c
t/c0.120
Camber pos.40% c
LE radius
α₀
CL MAX
α STALL
α ZERO-LIFT
(L/D) MAX
CD MIN
Cm c/4
Cl vs α
Drag Polar (Cl vs Cd)
L/D vs α
Cm vs α
Learn Airfoil Aerodynamics
A beginner's guide to everything in this tool — scroll to explore
What is an airfoil?

An airfoil (or aerofoil) is the cross-sectional shape of a wing. When air flows over it, the wing generates lift — the upward force that keeps an aircraft flying.

The key idea is simple: a wing works by turning the oncoming air downward. By Newton's third law, pushing that much air down produces an equal and opposite upward reaction on the wing — that's lift. Camber and angle of attack both increase how sharply the wing deflects the flow, which is why lift climbs as you tilt the wing up.

The same lift can be seen through pressure: the air accelerates over the upper surface and slows underneath, so by Bernoulli's principle the pressure on top is lower than below, and that pressure difference is the lift. (A common myth says the top air must "catch up" with the bottom air because it travels farther — that's not true, and it isn't needed. Even a flat plate or a symmetric wing like NACA 0012 makes lift once it's tilted, because it still turns the flow.)

Leading Edge (LE)
The front of the airfoil — where air first meets the wing. The shape here is critical for how smoothly air attaches at high angles.
Trailing Edge (TE)
The sharp rear edge where air from both surfaces meets. A sharp TE gives cleaner flow separation.
Chord
The straight-line distance from LE to TE. All other dimensions (camber, thickness) are expressed as a percentage of the chord.
Camber line
The curved centre line running from LE to TE, halfway between upper and lower surfaces. It represents the airfoil's curvature — shown as the orange dashed line in the 2D view.
NACA 4-digit code explained: The four digits tell you the shape directly. For NACA 2412: the first digit (2) is max camber as % of chord, the second digit (4) is camber position in tenths of chord (so 40%), and the last two digits (12) are max thickness as % of chord. NACA 0012 has zero camber — it's perfectly symmetric.
Shape controls

The three sliders under Geometry control the cross-sectional shape. Move them and watch the 2D profile and 3D wing update in real time.

Max Camber (m) — 0 to 9%
How curved is the wing?
A higher camber means a more curved upper surface. This increases lift even at zero angle of attack. Set to 0 for a symmetric airfoil (like NACA 0012) that only generates lift when tilted. Most general-aviation wings use 2–4% camber.
Camber Position (p) — 10 to 90%
Where is the peak curve?
This is how far along the chord the maximum camber sits. 40% (p=4) is a common value. Moving it forward sharpens the suction peak near the LE — which gives higher lift but also more abrupt stall. Further back is gentler and harder to stall.
Thickness (t) — 1 to 40%
How fat is the wing?
Thicker wings have a more rounded leading edge, which delays stall and allows more forgiving flight. But thick wings also have more drag. Fighter jets use very thin wings (4–6%). Gliders and light aircraft use 12–18% for efficiency at low speed.
Span — 1 to 6 chord lengths
How wide is the 3D wing?
Controls aspect ratio of the 3D wing. Doesn't change 2D aero coefficients (Cl, Cd) — those are per unit span. Span does affect the real-world lift force in the Lift Calculator.
Note: Camber position only has meaning when max camber is greater than zero. For a symmetric airfoil (m = 0), the camber position slider has no effect on the shape or the aerodynamics.
Angle of Attack

The angle of attack (AoA, or α) is the angle between the wing's chord line and the direction the aircraft is flying. It is the single most important variable in generating lift.

As you increase AoA, the wing presents a steeper face to the oncoming air, generating more lift. You can see Cl rise on the chart. This works well up to a point — but keep tilting and the airflow on the upper surface can no longer follow the curve and it separates from the wing. This is called a stall.

Before stall (α < α stall)
Lift increases nearly linearly with AoA. The Cl vs α chart is a straight line. This is the normal, efficient flying regime.
Approaching stall (within ~3°)
Lift still increases but the rate slows as airflow begins separating near the trailing edge. The model shows this with a slight curve near the top of the Cl chart.
Post-stall (α ≥ α stall)
Lift collapses. Drag spikes dramatically. In a real aircraft this is dangerous — a pilot must reduce AoA immediately to recover. Post-stall values on the charts are greyed out and marked as unreliable.
Try it: Set AoA to +5°, then slowly drag it up. Watch Cl increase on the chart. When AoA reaches the stall angle, the values turn red and the chart flattens. That's stall. Then bring AoA back down — lift recovers instantly (in real aircraft, recovery takes skill and altitude).
Negative AoA: A cambered airfoil still generates lift at 0°. To get zero lift, you have to tilt slightly negative to the zero-lift angle (α₀), shown in the readout strip. Symmetric airfoils have α₀ = 0°.
Flow conditions

The same airfoil shape can behave very differently depending on how fast the air is moving and what size the wing is. That's what the Reynolds number and Mach number capture.

Reynolds Number (Re)
Speed × Size ÷ Stickiness
Re combines airspeed, wing size (chord), and how viscous the air is. A large fast wing and a small slow one can have the same Re and behave almost identically. Re = ρVc/μ. Typical values: model aircraft 50k–300k, light aircraft 1M–3M, airliners 10M–50M.
Low Re (below 100k)
Drag is much higher, stall is less predictable, and the model becomes less accurate. This is the world of insects, small drones, and RC planes. The tool shows a warning below Re = 100k.
Mach Number (M)
Speed ÷ Speed of sound
M = 0.15 means flying at 15% of the speed of sound (~51 m/s at sea level). Below M ≈ 0.3, compressibility is negligible. Above M = 0.6 you get shockwave effects that this model can't fully capture — a warning appears. Leave Mach at 0.15 for typical low-speed aircraft.
Re = ρVc / μ At sea level: Re ≈ 68,000 × V (m/s) × c (m)
ρair density (kg/m³)
Vairspeed (m/s)
cchord length (m)
μdynamic viscosity (Pa·s)
Try it: Set Reynolds number to 50,000 (small drone territory). Notice how the drag polar shifts — Cd rises significantly and the stall angle may change. This shows why drone wings are designed differently from full-scale aircraft.
Reading the outputs

All the numbers in the At current AoA panel are dimensionless coefficients — they describe the wing's behaviour independent of its actual size or speed. To get a real force, you multiply by air density, velocity, and area (which is what the Lift Calculator does).

Cl — Lift coefficient
How much lift the wing generates at this AoA. A typical cruising Cl is 0.3–0.6. Cl max is the most lift possible before stall — higher is better for slow landing speeds.
Cd — Drag coefficient
Resistance to motion. You want this as small as possible. Typical clean airfoil Cd is 0.005–0.015. Cd rises sharply when approaching stall.
L/D — Lift-to-drag ratio
Efficiency. A glider with L/D = 40 travels 40 metres forward for every 1 metre it descends. A typical light aircraft has L/D ≈ 10–15. Higher is better for range and fuel economy.
Cm — Pitching moment
The tendency of the wing to rotate nose-up or nose-down. Cambered airfoils have a nose-down (negative) Cm, which must be counteracted by the tail. Symmetric airfoils have Cm ≈ 0.

Cl max and α stall are global properties of the airfoil, not just at the current AoA. They appear in the readout strip at the top of the main view and update whenever you change the shape.

L = Cl · ½ρV²S S = wing area = span × chord
Llift force (N)
Cllift coefficient (dimensionless)
ρair density (kg/m³)
Vairspeed (m/s)
Swing area = span × chord (m²)
L/D max is the sweet spot. The AoA that gives the highest L/D is where the wing is most efficient — not the AoA with the highest Cl. For best range, fly near the L/D max angle. The L/D chart shows you exactly where this is.
The polar charts

The four charts below the 3D/2D views show the airfoil's full aerodynamic behaviour across the entire range of angles. Greyed-out regions are post-stall and unreliable — treat them as approximate only.

Cl vs α (top left)
The lift curve. Should be a near-straight line rising from bottom-left to top-right, then bending and dropping at stall. The slope is about 2π per radian for any airfoil — roughly 0.11 per degree. The intercept on the horizontal axis is the zero-lift angle α₀.
Drag polar — Cl vs Cd (top right)
Shows how drag increases as you generate more lift. The best airfoils have a narrow, vertical drag polar — meaning you get lots of lift for very little drag increase. The sweet spot is near the bottom of the curve where the drag bucket sits.
L/D vs α (bottom left)
Shows efficiency at each angle. Look for the peak — that's the angle of best glide. Below that peak you're leaving efficiency on the table; above it you're wasting energy on drag.
Cm vs α (bottom right)
Pitching moment vs angle of attack. For a stable aircraft you want Cm to decrease (become more negative) as AoA increases — this naturally pushes the nose back down after a disturbance. A flat or rising Cm line can mean instability.
In Compare mode, an amber overlay shows a second airfoil alongside the current one. Both polars are plotted together so you can directly compare, for example, NACA 2412 vs NACA 4412 — same thickness but different camber.
Tips & workflow

Here are a few starting points depending on what you're trying to learn or design:

I want maximum lift (e.g. slow UAV)
Increase camber (m) toward 6–8%, set camber position (p) around 4–5, use moderate thickness (12–15%). Then use the Find tool to search for airfoils with your target Cl at a given AoA.
I want minimum drag (e.g. glider)
Keep camber moderate (2–3%), use a thinner section (10–12%), and operate near the L/D max angle. Look for a narrow drag polar on the Cl vs Cd chart.
I'm writing a research paper
Switch to Fidelity mode to compare L1 (thin airfoil theory) against L2 (XFoil-calibrated data) and add your own CFD results under L3. The error table shows the deviation between models.
I want to explore stall behaviour
Set a moderate AoA (~10°), then slowly increase it past the stall angle shown in the sidebar. Compare a thick airfoil (t=18%) with a thin one (t=8%) — thicker wings stall more gently.
Use the Find tab — instead of manually sweeping the sliders, click Find in the navigation bar and enter the Cl, Cd, and operating AoA you need. The tool will sweep the entire NACA 4-digit design space and rank the best matches for you.
Remember: This tool uses mathematical models, not real wind tunnel data (except for the 9 preset XFoil profiles in Fidelity mode). Results are good for understanding trends and comparisons, but always validate against experimental data or CFD before using in a real design.

Built by Aritra Parekh · AS-level aerospace student · Questions or corrections? The methodology and references are in the About tab.

About the creator

Aritra
Parekh

AS-level student pursuing aerospace engineering. This tool was independently built as a passion project — a browser-based aerodynamic analysis platform that makes airfoil data genuinely accessible to students and researchers.

If you have questions about the tool, found a bug, or just want to talk aerospace, reach out.

Reveal email →
About this tool

NACA Airfoil Explorer computes aerodynamic polars for any NACA 4-digit airfoil using thin airfoil theory with Glauert thickness correction, Prandtl-Glauert compressibility, and Reynolds-number drag scaling. The 9 preset profiles include precomputed XFoil data at Re = 1×10⁶ for direct comparison.

The 3D wing viewer uses Three.js with real NACA geometry — same cosine-spaced coordinates used for the aerodynamic model. Every number shown has a calibrated uncertainty estimate. Post-stall values are explicitly flagged as extrapolations.

10
XFoil presets
4k+
NACA profiles searchable
3
Fidelity levels
References

[1] Abbott, I.H., von Doenhoff, A.E. (1959). Theory of Wing Sections. Dover.
[2] Katz, J., Plotkin, A. (2001). Low-Speed Aerodynamics, 2nd ed. Cambridge UP.
[3] Anderson, J.D. (2010). Fundamentals of Aerodynamics, 5th ed. McGraw-Hill.
[4] Drela, M. (1989). XFOIL: An Analysis and Design System for Low Reynolds Number Airfoils. LNEF 54.
[5] Schlichting, H. (1979). Boundary Layer Theory, 7th ed. McGraw-Hill.
[6] Abbott, I.H., von Doenhoff, A.E., Stivers, L.S. (1945). NACA TR-824.

Free Airfoil Tools for Aerospace Students and Researchers

NACA Airfoil Explorer provides the most comprehensive free airfoil tools available in a browser. Whether you need to calculate the lift coefficient of a NACA 2412, plot a drag polar for the NACA 0012, or compare thin airfoil theory against XFoil data for your research paper, this tool covers it all — with no download, no account, and no cost.

Airfoil Tools Feature List

Interactive 3D wing visualisation. Live aerodynamic polar charts: Cl vs angle of attack, drag polar (Cl vs Cd), L/D ratio, and pitching moment Cm. Real XFoil data at Reynolds number 1×10⁶ for NACA 0012, NACA 2412, NACA 4412, NACA 2415, NACA 4415, NACA 0009, NACA 6412, NACA 0015, and NACA 1408. Constraint-based airfoil search across the full NACA 4-digit design space. Real-world lift force calculator using ISA standard atmosphere. CFD data import from SimScale, OpenFOAM, and XFLR5. Export to Polar CSV, Selig DAT, LaTeX, and methodology text for academic use.

NACA Airfoil Data

NACA 0012 airfoil: symmetric, 12% thickness, minimum drag Cd ≈ 0.0054 at Re=1e6. NACA 2412 airfoil: 2% camber at 40% chord, 12% thickness, zero-lift angle −2.07°, widely used in general aviation. NACA 4412: 4% camber, high lift for low-speed applications. All profiles computed with thin airfoil theory and validated against NACA Technical Report 824 (Abbott, von Doenhoff, Stivers, 1945).

References

Abbott and von Doenhoff (1959) Theory of Wing Sections. Katz and Plotkin (2001) Low-Speed Aerodynamics. Anderson (2010) Fundamentals of Aerodynamics. Drela (1989) XFOIL. Schlichting (1979) Boundary Layer Theory. NACA TR-824 (1945).