Home▸Nanotechnology & MEMS▸Ballistic vs Diffusive Phonon Transport

Ballistic vs Diffusive Phonon Transport

Interactive 3D phonon-transport simulator: shrink a nanoscale sample below its phonon mean free path and watch heat carriers switch from a diffusive random walk to straight ballistic flight, collapsing the effective thermal conductivity below its bulk value.

Nanotechnology & MEMS3DAdvanced60 FPS💨 Air & Wind

Watch heat-carrying phonons cross a nanoscale sample between a hot face and a cold face. When the sample is much thicker than the phonon mean free path, phonons random-walk across it in a classic diffusive zig-zag and Fourier's law holds. Shrink the sample below the mean free path and phonons increasingly fly straight through without scattering at all — ballistic transport — and the effective thermal conductivity collapses below the bulk value, exactly as it does in real nanowires and thin films.

⚙ Under the hood

Slide a nanoscale sample's thickness below the phonon mean free path and watch heat carriers switch from a diffusive random walk to straight ballistic flight, with a live Knudsen number and κ_eff/κ_bulk readout showing thermal conductivity collapse.

phonon transportnanothermodynamicsthermal conductivitymean free pathballistic transportKnudsen numbernanoscale heat conduction

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install