Kutta in the Browser: Same Code, a Different Frame Budget

crg@crg.eti.br (Cesar Gimenes) — Sun, 16 Aug 2026 10:30:00 -0300

Kutta now runs inside a browser tab. Same source as the desktop build, GOOS=js GOARCH=wasm, no fork, no duplicated file holding a “web” version of the solver.

Speed is what you pay. A solver step costs 6.1 ms under wasm against 2.3 ms native, measured on the 360x200 grid the app runs, on an M4 Mac, same solver compiled for both targets on the same machine. Factor of 2.6.

Kutta, a Tiny Wind Tunnel in Go

crg@crg.eti.br (Cesar Gimenes) — Wed, 08 Jul 2026 00:30:00 -0300

You can explain lift with a diagram and an equation. It rarely sticks. Watch a wake peel off the back of a wing while you turn the angle of attack, and it sticks immediately. That gap is the whole reason Kutta exists.

It is a small 2D wind tunnel written in Go, rendered with Ebitengine, running as a single desktop app.

The idea never grew past the first sketch: stream air past an airfoil and make the flow visible. Change the angle of attack and the field reacts. Toggle between speed, vorticity and a pressure-like field. Draw your own shape. Cut a wing into a wing and a flap, animate the flap, and watch the wake go unstable when the geometry or the angle gets greedy.

Ebitengine on Cesar Gimenes

Kutta in the Browser: Same Code, a Different Frame Budget

Kutta, a Tiny Wind Tunnel in Go