HEAD LOSS
Fluid Flow
Summary
The main points of this chapter are summarized below.
Head Loss Summary
•
Head loss is the reduction in the total head (sum of potential head, velocity head,
and pressure head) of a fluid caused by the friction present in the fluid’s motion.
•
Frictional loss is that part of the total head loss that occurs as the fluid flows
through straight pipes.
•
Minor losses are the head losses that occur due to bends, elbows, joints, valves,
and other components. Any time the flow experiences a change in direction or
a change in cross-sectional area, it will experience a head loss.
•
The friction factor for fluid flow can be determined using a Moody Chart if the
relative roughness of the pipe and the Reynolds number of the flow can be
determined.
•
Darcy’s equation can be used to calculate frictional losses.
•
A special form of Darcy’s equation can be used to calculate minor losses.
•
The length of pipe that would cause the same head loss as a valve or fitting can
be determined by multiplying the value of L/D for the component found in
handbooks or vendor manuals by the diameter of the pipe.
HT-03
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