Example 2

Problem 2 

Determine energy loss if – 

Glycerin at 25C L = 30m D = 150 mm = 0.15 m V = 4.0 m/s 

Density = 1258 k/m3 Dynamic viscosity = 0.96 Pa.s 

First determine the Reynolds number to determine if it is laminar flow 

η ρ DV NR = 

= 4.0 * 0.15 * 1258 / 0.96 = 786 < 2000  - Laminar flow  

Therefore Darcy’s equation   hL = f * (L/D) * (v2/2g) 

 = 64/NR * (L/D) * (v2/2g) 

 = 13.2 m