Surge Analysis - Water Hammer

These equations are primarily used for calculating pressure drops and flow rates. However, a modified Reynolds number must be used. When calculating flow rate or internal pipe diameter, a modified Reynolds number must be calculated first using the up or down stream calculations to run these calculations. No internal roughness considered.

Friction factor is solved using Newton-Raphson method.

𝑓 − Friction Factor

D – Inside Pipe Diameter[in]

𝜀 − Pipe Roughness[in]

 
The momentum continuity equations


Infinite difference form could be seen:


The equations simplify to


These equations combined linearly using an unknown multiplier 𝛌
Further



Equation E becomes ordinary differential equation


The solution of this equation yields the two-particular value of

By substituting the values of  in the equation, the particular manner in which x and t are related is
 

Input Parameters

1. To create a new case, click the “Add Case” button
2. Select the Unknown and desired Flow Equation.
3. Enter Case Name, Location, Date and any necessary notes.
4. Fill out all required fields.
5. Make sure the values you are inputting are in the correct units.
6. Click the CALCULATE button.

• Flowing Temperature(°F)
• Liquid Specific Gravity
• Upstream Pressure(psig)
• Flow Rate (MCFD)
• Internal Pipe Diameter(in)
• Kinematic Viscosity
• Length of Pipeline(mi)
• Upstream Elevation(ft)
• Downstream Elevation(ft)

   

Outputs/Reports

1. View the results.
2. If an input parameter needs to be edited be sure to hit the CALCULATE button after the change.
3. To SAVE, fill out all required case details then click the SAVE button.
4. To rename an existing file, click the SAVE As button. Provide all case info then click SAVE.
5. To generate a REPORT, click the REPORT button.
6. The user may export the Case/Report by clicking the Export to Excel/PowerPoint icon.
7. To delete a case, click the DELETE icon near the top of the widget.

• Flow Rate(ft/sec.)
• Pressure Drop [psi/mi]
• Calculated modified Reynolds Number
• Upstream Pressure(psi)
• Downstream Pressure(psi)
• Internal Pipe Diameter(in)
• Erosional Velocity (ft/sec.)
• Sonic Velocity (ft/sec.)

       

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