Question

Air at 80oF is to flow through a 2-ft pipe at an average velocity of 6 ft/s. What size pipe should be used to move water at 60oF and average velocity of 3.5 ft/s if Reynolds number similarity is enforced?

Answer 1

D=0.245 ft

Step-by-step explanation:

Reynolds number for air

Rₐ(air)=Rₐ(water)

`(pVD)/(u)=(pVD)/(u)`

Simplify it we get

`(VD)/(v)=(VD)/(v)\\(6*2)/(1.69*10^(-4) )=(3.5D)/(1.21*10^(-5) )\\`

D=71005.95/289256

D=0.245ft