IntroductionHere you find 17 WANDA cases which help to understand the waterhammer phenomena. All cases include a movie. In order to play the movie, you must install the Techsmith ScreenCapture Codec (more information - Download). Example 1Description: Instantaneous valve closure at the end of a frictionless pipe Phenomenon: Propagation of positive pressure wave download movie ![](/download/attachments/53542947/case01.png?version=1&modificationDate=1251832258000&api=v2)
System data Property | Value |
---|
Diameter | 500 mm | Length | 10000 m; | Friction | No friction | Wave speed | 1000 m/s | Initial velocity | 1.0 m/s |
Valve data: - Butterfly valve
- instantaneous closure (within 1 timestep)
![](/download/attachments/53542947/case01a.png?version=1&modificationDate=1251832258000&api=v2) Example 2Description: Instantaneous valve closure in the middle of a frictionless pipe Phenomenon: Propagation of positive and negative pressure wave download movie ![](/download/attachments/53542947/case02.png?version=1&modificationDate=1251832258000&api=v2)
System data Property | Value |
---|
Diameter | 500 mm | Length | 5000 m; | Friction | No friction | Wave speed | 1000 m/s | Initial velocity | 1.0 m/s |
Valve data: - Butterfly valve
- instantaneous closure (within 1 timestep)
![](/download/attachments/53542947/case02b.png?version=1&modificationDate=1251832258000&api=v2) Example 3Description: Instantaneous valve closure at the end of a pipe with friction (line packing) Phenomenon: Propagation of positive pressure wave and line packing download movie ![](/download/attachments/53542947/case03.png?version=1&modificationDate=1251832577000&api=v2)
System data Property | Value |
---|
Diameter | 500 mm | Length | 10000 m; | Friction factor | 0.0222 (k = 1 mm) | Wave speed | 1000 m/s | Initial velocity | 1.0 m/s |
Valve data: - Butterfly valve
- instantaneous closure (within 1 timestep)
![](/download/attachments/53542947/case03b.png?version=1&modificationDate=1251832577000&api=v2) Example 4Description: Instantaneous valve closure at the end of a pipe with friction and surge tower as the anti-surge device Phenomenon: Effect of surge tower on pressure waves download movie ![](/download/attachments/53542947/case04.png?version=1&modificationDate=1251832577000&api=v2)
System data Property | Value |
---|
Diameter | 500 mm | Length | 10000 m; | Friction factor | 0.0222 (k = 1 mm) | Wave speed | 1000 m/s | Initial velocity | 1.0 m/s |
Valve data: - Butterfly valve
- instantaneous closure (within 1 timestep)
*Surge tower: - Area = 0.01 m2 (vertical pipe with 113 mm internal diameter)
Example 5Description: Pump trip with small polar moment of inertia Phenomenon: Propagation and development of negative pressure wave download movie ![](/download/attachments/53542947/case05.png?version=1&modificationDate=1251832968000&api=v2)
System data Property | Value |
---|
Diameter | 500 mm | Length | 10000 m; | Friction factor | 0.0218 (k = 0.25 mm) | Static head | 2.0 m | Wave speed | 1000 m/s | Initial velocity | 0.6 m/s |
Pump data: - Duty point is 100 m3/h at 17 m head
- Polar moment of inertia 0.1 kgm2
![](/download/attachments/53542947/case05b.png?version=1&modificationDate=1251832968000&api=v2) Example 6Description: Pump trip with large polar moment of inertia Phenomenon: Propagation and development of negative pressure wave download movie ![](/download/attachments/53542947/case06.png?version=1&modificationDate=1251832968000&api=v2)
System data Property | Value |
---|
Diameter | 500 mm | Length | 10000 m; | Friction factor | 0.0218 (k = 0.25 mm) | Static head | 2.0 m | Wave speed | 1000 m/s | Initial velocity | 0.6 m/s |
Pump data: - Duty point is 100 m3/h at 17 m head
- Polar moment of inertia 2.0 kgm2
![](/download/attachments/53542947/case06b.png?version=1&modificationDate=1251832998000&api=v2) Example 7Description: Pump trip with small polar moment of inertia and surge tower as the anti-surge device Phenomenon: Effect of surge tower download movie Image Added
System data Property | Value |
---|
Diameter | 500 mm | Length | 10000 m; | Friction factor | 0.0218 (k = 0.25 mm) | Static head | 2.0 m | Wave speed | 1000 m/s | Initial velocity | 0.6 m/s |
Pump data: - Duty point is 100 m3/h at 17 m head
- Polar moment of inertia 0.1 kgm2
Surge tower: Image Added Image Added Example 8Description: Two frictionless pipes in series with different diameters; instantaneous valve closure at the end of the system in the pipe with smallest diameter (reflection) Phenomenon: Effect of diameter change on pressure wave - reflection download movie Image Added
System data Property | Value |
---|
Diameter Pipe 1 | 500 mm | Diameter Pipe 2 | 250 mm | Length | 5000 m; | Friction factor | no friction | Wave speed | 1000 m/s | Initial velocity D=250 | 1.0 m/s |
Valve data: - Butterfly valve; instantaneous closure (within 1 timestep)
Image Added Example 9Description: Two frictionless pipes in series with different diameters; instantaneous valve closure at the end of the system in the pipe with largest diameter (reflection) Phenomenon: Effect of diameter change on pressure wave - reflection download movie Image Added
System data Property | Value |
---|
Diameter Pipe 1 | 250 mm | Diameter Pipe 2 | 500 mm | Length | 5000 m; | Friction factor | no friction | Wave speed | 1000 m/s | Initial velocity D=250 | 1.0 m/s |
Valve data: - Butterfly valve; instantaneous closure (within 1 timestep)
Image Added Example 10Description: Two frictionless pipes in series with different pressure wave celerity; instantaneous valve closure at the end of the system in the pipe with smallest wave celerity (reflection) Phenomenon: Effect of wave celerity change on pressure wave (e.g. change in pipe material) download movie Image Added
System data Property | Value |
---|
Diameter both pipes | 500 mm | Length | 5000 m; | Friction factor | no friction | Wave speed pipe 1 | 1000 m/s | Wave speed pipe 2 | 200 m/s | Initial velocity | 1.0 m/s |
Valve data: - Butterfly valve; instantaneous closure (within 1 timestep)
Image Added |