2D Tesla Valve

A Tesla valve has no moving parts, yet fluid passes easily one way and struggles the other way. The two channels below are identical and pumped equally hard — the top one forward, the bottom one in reverse. Forward flow shoots across the bucket mouths, hugging the zigzag duct. Reverse flow is aimed by each bend straight into a bucket, swirls around inside, and is thrown back against the oncoming stream. The flow numbers and the ratio are measured live from a real fluid simulation (lattice-Boltzmann) — nothing is scripted.

FORWARD →pump pushes left→rightflow –
← REVERSEsame pump, pushing right→leftflow –
developing flow…

Controls

Background brightness and dot color show local flow speed. “flow” is the time-averaged volumetric flow rate through the duct (arbitrary units). Both valves share the same geometry and pump strength; only the pump direction differs.