Initial Condition
Hot centre
Gaussian at (½,½) — symmetric diffusion
Two sources
offset Gaussians — watch them merge
Hot ring
annular source — inward collapse
Gradient
left hot, right cold — smooth diffusion front
Checkerboard
alternating blocks — fast high-mode decay
Diffusivity α
0.06
Radiation λ
0.00
Speed
8
Brush
5
Neumann BC
⏸ Pause
✕ Clear
Left drag — add heat
Right drag / Ctrl — remove heat
Neumann = insulating walls
Dirichlet = cold walls
α:
0.06
T
max
:
1.000
⟨T⟩:
0.0000
t:
0.00
∂u/∂t = α∇²u − λu
Drag
— paint heat • right drag = cool
α slider
— faster diffusion
Space
— pause / play