In this part we will calculate Reynolds number for the pipe sizing calculation example. Refer Part-1 for understanding the problem statement and the solution steps.
From the concept of Reynolds number, it can be written that
Reynolds number (Re) = ρ*s*L/μ ………………………eq.1
ρ – Density of the fluid
s – Velocity of the fluid
L – Characteristic length
μ – Dynamic viscosity
For our water pipe sizing calculation example, we have the following inputs (refer Part-1):
Fluid used = water
So, density of fluid (ρ) = 1000 kg/m3
Dynamic viscosity of fluid (μ) = 0.000894 Pa-S
Assumed flow rate = 0.5 Liter/sec = 0.0005 cubic-meter/sec
Assumed pipe diameter = 20 mm = 0.02 m
So, velocity of the fluid (s) = 0.0005/(π*0.25*0.02*0.02) = 1.591 m/sec
Characteristic length (L) = 0.02 m
By putting all the input values in the eq.1, we get
Re = 35592.84
As, the Reynolds number is greater than 4000, so, the flow in our case is of turbulent type.
The next part (Part-7) will deal with the selection of correct moody friction factor.