Fluids & atmospheric physics › Rayleigh–Bénard convection
Rayleigh–Bénard convection laboratory
Heat a fluid from below and watch organised convection cells emerge from microscopic disturbances.
What to notice
Below the critical Rayleigh number, heat crosses the layer mainly by conduction. Near Ra ≈ 1708, buoyancy overcomes viscosity and thermal diffusion: warm fluid rises, cool fluid sinks, and counter-rotating rolls appear.
Ra = g α ΔT H³ / (νκ) · Pr = ν/κ · Nu = total heat transfer / conductive heat transfer
Educational reduced-order model. It visualises the instability and scaling relationships, not engineering-grade computational fluid dynamics.