Conduction / Convection / Radiation Heat Transfer simulation
What's on screen
One main canvas that changes completely when you switch between the three mode tabs. Each mode has its own unique visual scene, animated elements, and governing equation. A mini comparison bar at the bottom left always shows all three Q values simultaneously so you can see which mode dominates at your current settings.
Three modes, three different visualizations:
Conduction (blue tab): A wall slab with a smooth temperature gradient from hot red (left) to cool blue (right). Animated vibrating dots inside the wall represent molecular/phonon energy transfer. Heat flow arrows emerge from the right face. A dashed line below shows the linear temperature profile. The wall thickness dimension, material name, and k value are labeled on the wall. The full Fourier's law calculation is shown at the bottom with actual numbers.
Convection (green tab): A hot surface plate at the bottom with fluid flowing over it. A curved boundary layer line separates the near-surface slow flow from the free stream. Velocity arrows grow longer away from the surface (no-slip at wall, free stream velocity far away). Rising heat plumes animate from the surface. An exponential temperature profile curve is drawn on the right edge. The convection type (free air, forced water, boiling, etc.) and h value are labeled.
Radiation (red tab): A hot glowing body on the left radiating wavy electromagnetic arrows toward surroundings on the right. The body glows with increasing intensity as temperature rises. An electromagnetic spectrum bar at the bottom shows Wien's law peak wavelength shifting from infrared toward visible as temperature increases. The emissivity and surface type are labeled. The full Stefan-Boltzmann calculation appears at the bottom.
Key slider experiments::
Set T₁=200°C, T₂=25°C. Switch between all three modes. With steel wall (k=50), conduction gives ~175,000 W. With forced air (h=25), convection gives ~4,375 W. Radiation with oxidized steel (ε=0.8) gives ~1,800 W. Conduction through a thin steel wall crushes everything.
Now change conduction material from steel to air (insulation). Q drops from 175,000 to ~91 W. That's a 2000× reduction. This is why air gaps are the best insulators.
Crank T₁ to 1000°C on radiation mode. Q jumps to ~120,000 W. Now switch to convection with forced air at the same ΔT. Only ~24,000 W. Radiation dominates at high temperature. This is why furnace design is mostly a radiation problem.
On convection, drag slider 4 from "free air" (h=5) to "boiling" (h=10000). Q jumps 2000×. This is why boiling heat transfer is used in nuclear reactors and electronics cooling.
The Wien's law marker on the radiation spectrum shifts as you change T₁. At 200°C it's deep infrared (~6 μm). At 1000°C it's near-infrared (~2.3 μm). At 5000°C it enters the visible range. This is why hot objects start glowing red then white.