Minor losses in
pipe flow
In fluid mechanics, pipe flow is a type of liquid flow within a closed conduit, such as a pipe or tube. The other type of flow within a conduit is open channel flow.
These two types of flow are similar in many ways, but differ in one important as ...
are a major part in calculating the flow, pressure, or energy reduction in
piping
Within industry, piping is a system of pipes used to convey fluids (liquids and gases) from one location to another. The engineering discipline of piping design studies the efficient transport of fluid.
Industrial process piping (and accomp ...
systems. Liquid moving through pipes carries momentum and energy due to the forces acting upon it such as pressure and gravity. Just as certain aspects of the system can increase the fluids energy, there are components of the system that act against the fluid and reduce its energy, velocity, or momentum. Friction and minor losses in pipes are major contributing factors.
Friction Losses
Before being able to use the minor head losses in an equation, the losses in the system due to friction must also be calculated.
Equation for friction losses:
= Frictional head loss
= Downstream velocity
= Gravity of Earth
=
Hydraulic radius
=Total length of piping
=
Fanning friction factor
The Fanning friction factor, named after John Thomas Fanning, is a dimensionless number used as a local parameter in continuum mechanics calculations. It is defined as the ratio between the local shear stress and the local flow kinetic energy ...
Total Head Loss
After both minor losses and friction losses have been calculated, these values can be summed to find the total head loss.
Equation for total head loss,
, can be simplified and rewritten as: