Do Fish Swim Like Multi-Element Airfoils?
In nature, a school of fish moves as a coordinated system. Each fish swims in the wake of another, taking advantage of pressure differences and induced flows that reduce drag and save energy. It’s a clean example of fluid mechanics at work — and not too different from how engineers design multi-element airfoils for high lift.
The image above shows a simulation created from fish-shaped outlines. The shapes were first traced as simple drawings and then captured using Airfoil Digitizer. Airfoil Digitizer lets you turn almost any outline — hand-drawn, scanned, or imported — into an analysis-ready shape. You are not limited to NACA airfoils or standard sections. If you can sketch it, you can analyze it.
After digitizing the shapes, I placed them together and ran a potential flow solution in MultiElement Airfoils. This solver computes the velocity and pressure field around multiple bodies at once, and shows how they interact. The colored contours represent pressure: blue for low (suction) regions and red for higher pressure. You can see how each “fish airfoil” changes the flow around its neighbors, very much like the interaction between a slat, a main wing, and a flap.
This is the interesting part: even with playful shapes, the physics is still there. You get wake shielding, suction peaks, and local acceleration in the gaps. That’s the same family of effects we care about in real applications — multi-element wings, hydrofoils, propeller/wing interference, and UAV control surfaces working close together.
The workflow here was:
1) Sketch or outline a shape
2) Capture it with Airfoil Digitizer
3) Arrange multiple elements and solve the flow in MultiElement Airfoils
4) Visualize pressure and interaction
It’s a fun demonstration, but also a serious one. Airfoil Digitizer gives you full control over the geometry. MultiElement Airfoils lets you study how multiple lifting surfaces behave together, not just one at a time. Together they make it easy to explore ideas, test concepts, and see the aerodynamics before you ever build a model.
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Best regards,
Patrick
