LearnChemE

Introduction to Pipe Flow: Screencast

Presents the mechanical energy equation and introduces the concepts of major and minor head loss.

We suggest that after watching this screencast, you list the important points as a way to increase retention.

Shows how to calculate major losses using the Moody chart.

We suggest that after watching this screencast, you list the important points as a way to increase retention.

Important Equations:

The Reynolds number, Re, is used to determine the flow regime.

Re=ρUDμ=UDν

where U = freestream velocity
ρ = fluid density
μ = fluid dynamic viscosity
ν = fluid kinematic viscosity
D = pipe diameter

The governing equation for pipe flow:

P1γ+α1V122g+z1+hP=P2γ+α2V222g+z2+hT+hL

hL=fLDV22g

where γ = specific weight of the fluid
P = pressure at each point in the pipe
V = velocity at each point in the pipe
g = gravitational constant
z = height at each point in the pipe, referenced to the same point at z=0
α = kinematic energy parameter
hL = head loss
f = frictional factor, which can be determined using the Moody chart
L = length of the pipe

Although hP is the energy of the pump, and hT is the energy of the turbine, they are usually not included in the basic energy equation, but they must be used when pumps and/or turbines are part of the system.