Convection in Water Heated from Below

A beaker of water sits on a tripod with a burner beneath its base. The flame heats the water, reducing its density so the warm parcel rises. At the surface it spreads, cools, becomes denser and sinks along the sides, creating a continuous buoyancy‑driven convection loop that transports heat through the whole volume.

Students can turn the burner on and off, drop a crystal of potassium permanganate to release purple dye, and toggle visual aids such as temperature colour mapping, sawdust particles and flow‑arrow indicators. The restart button returns the system to its initial state, allowing repeated experiments.

By observing how the dye and particles follow the flow, learners explore concepts of heat transfer, fluid motion, the Boussinesq approximation, and the interplay between temperature gradients and buoyancy forces, reinforcing topics in fluid mechanics and thermodynamics.