💧 SPH Dam Break

Particles 300 Gravity 0.5 Viscosity 0.3 Pressure stiffness 200 Rest density ρ₀ 1.0

Colour By

300

Particles

0.0

Kin. Energy

0.0

Max speed

FPS

SPH (Monaghan 1992):
Each particle carries mass, velocity, and density.
Pressure: p = k(ρ−ρ₀)
Kernel: cubic-spline W(r,h)
Forces: pressure gradient + viscosity + gravity
Euler integration, dt=0.004

What It Demonstrates

This simulation uses Smoothed Particle Hydrodynamics (SPH) — a Lagrangian mesh-free method widely used in astrophysics, oceanography, and game engines. Each water particle interacts with neighbours within a smoothing radius h. Pressure forces prevent compression; viscosity damps velocity differences; gravity pulls everything down. The result is a realistic dam-collapse and wave-runup with splashing and free-surface dynamics.

How to Use

Click Reset Dam to restart the simulation. Increase Gravity for a faster, more violent collapse. Raise Viscosity to simulate honey-like flow. Increase Pressure Stiffness to make the fluid less compressible. Switch color modes to visualise speed, pressure, or density fields.

Did You Know?

SPH was originally invented by Lucy (1977) and Gingold & Monaghan (1977) to simulate astrophysical phenomena. Today it powers the fluid simulations in video games like Half-Life 2's water, hurricane storm surge models, and blood-flow in arteries.