Chemical & Materials
Heat Transfer Lab
Hold the two ends of a rod at fixed temperatures and watch heat diffuse: the profile (and the colour strip) animate from a cold start toward the straight-line steady gradient. It's solved by the explicit finite-difference scheme, which is only stable while α·dt/dx² ≤ ½ — the CFL limit — so it also shows why your time step matters in any transient simulation. Drag the end temperatures and the diffusivity to see how fast equilibrium arrives.
150°
Left end
20°
Right end
85°
Steady midpoint
Heat flows from hot to cold until the rod reaches the straight-line steady gradient (dashed). The solver is an explicit finite-difference scheme — stable only while α·dt/dx² ≤ ½, the CFL limit; past it the simulation would explode, which is why your step size matters.
How to use this simulation
Hold the two ends of a rod at fixed temperatures and watch heat diffuse: the profile (and the colour strip) animate from a cold start toward the straight-line steady gradient. It's solved by the explicit finite-difference scheme, which is only stable while α·dt/dx² ≤ ½ — the CFL limit — so it also shows why your time step matters in any transient simulation. Drag the end temperatures and the diffusivity to see how fast equilibrium arrives.
Everything runs in your browser — no sign-up, no download. Change a value and the result updates instantly, so you can build a feel for how each input shapes the outcome. It pairs with Crameleon's practice exams and step sheets when you want to go from intuition to working the problems.