Splash 2D-LBM Simulator

An interactive browser-native CFD tool built on the Lattice Boltzmann Method — designed for education, demonstration and rapid flow visualisation.

What is this tool?

This simulator solves the incompressible Navier–Stokes equations in 2D using the Lattice Boltzmann Method (LBM). Unlike solvers that discretise the macroscopic equations directly, LBM works at a mesoscopic level — simulating the statistical behaviour of fluid molecules on a discrete lattice. The result is a solver that is explicitly parallel, numerically stable for low-to-moderate Reynolds numbers, and fast enough to run in real-time in a browser.

Quick Start

1. A cylinder is shown by default at Re = 200. Kármán vortex shedding appears within seconds.
2. Use the Draw tool to paint custom obstacles directly on the canvas.
3. Increase Reynolds number to observe transition to chaotic wakes.
4. Load geometry via Upload .stl — automatically projected onto the 2D grid.
5. Change Angle of Attack to rotate the inlet flow direction.
6. Switch to Vorticity or Pressure field for deeper insight.
7. Export a GIF or PNG of your simulation.