Fluid Dynamics

Hydraulic System Applications

What is Pressure Head or Static Head

In hydraulic systems, pressure head describes the total energy of a system by relating it to the height of a liquid column that would be produced if the system was static [1].

To further explain, this means all the energy was transferred into static pressure that goes into creating the liquid column.

Losses in Pipes

Major vs Minor Head Loss

Imperfections in pipe systems lead to an energy loss called head loss. There are two main types:

Minor Losses: occur due to interruptions in the pipe’s flow such as:
1. bends and other fittings
2. expansions or contractions
3. pipe entrances or exits
4. valves [3]
Major Losses: occur due to friction between the fluid and the wall of the pipe [4]

Illustration of lost potential due to head loss [5]

References

[1]	N. Connor, "What is Pressure Head – Definition," Thermal Engineering , 22 May 2019. [Online]. Available: https://www.thermal-engineering.org/what-is-pressure-head-definition/. [Accessed 30 July 2021].
[2]	Tec Science, "Pressure Head and Head Loss," 17 July 2020. [Online]. Available: https://www.tec-science.com/mechanics/gases-and-liquids/pressure-head-and-head-loss/. [Accessed 30 July 2021].
[3]	F. M. White, "6.9: Minor or Local Losses in Pipe Systems," in Fluid Mechanics Eight Edition, New York, McGraw-Hill Education, 2016, p. 380.
[4]	N. Connor, "What is Classification of Head Loss – Definition," Thermal Engineering , 22 May 2019. [Online]. Available: https://www.thermal-engineering.org/what-is-classification-of-head-loss-definition/. [Accessed 30 July 2021].
[5]	J. Fuchs, "Pumps - Pump Performance Curves," Cleaning Technologies Group, 5 March 2012. [Online]. Available: https://techblog.ctgclean.com/2012/03/pumps-pump-performance-curves/. [Accessed 30 July 2021].

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