Film Condensation — Nusselt TheoryLaminar liquid film on a cold vertical plate

Wall subcooling ΔT 20 K

Plate height L 0.60 m

Probe height x 0.30 m

Interface waves

Cold wall

Condensate film

Saturated vapour

Probe height

Local & average heat transfer

δ at probe–

h(x) at probe–

δ at plate foot–

h̄ average–

Heat rate Q′–

Condensate ṁ′–

Re at foot–

–

Film thickness is exaggerated for visibility — a real condensate film is only tens to a few hundred microns thick. Velocities and drip timing are drawn to scale relative to each other, sped up for legibility.