Rainfall causes a uniform 0.5 mm film of water for form over horizontal 0.05 m diameter tube. Wind at 25 degrees and 40% humidity blows across the tube at 20 km/h.

Nu_D=0.25[Re_D]^0.6 Pr^0.38

The fluid properties are as given below:

kinetic viscosity =1.15x10-5

density= 1.15

For air-water vapour mixture, D=2.6x10^-5

Sc=0.60

For dry saturated steam at 25 degrees celsius

the density is 0.0231.

liquid water density = 1000