Headloss through a hydropneumatic tank

Product(s): Hammer
Version(s): 08.11.XX.XX, 10.XX.XX.XX
Area: Output and Reporting


How can I determine the headloss through a hydropneumatic tank for a given timestep in HAMMER?


There is no report that shows the exact headloss through the tank. However, there is a relatively easy way to determine it.

  • First, enter a number in the "Report Period" field of the hydropneumatic tank properties. This represents the increment of timesteps at which some extended data will be reported.
  • Next, compute the transient simulation.
  • Go to Reports > Transient Analysis Reports > Transient Analysis Detailed Report. Scroll down near the bottom of the report and you will see a table starting with this:

** Gas vessel at node HT-2 **

Time Volume Head-Gas Head-Pipe Inflow

(s) (m3) (m) (m) (cms)

To determine the headloss, you basically look at the difference between the values for "Head-Pipe" and "Head-Gas". When the value for "Inflow" is positive, that means the tank is filling, so the head in the tank (Head-Gas) may be less than the head in the pipe (Head-Pipe) due to headlosses. When the "Inflow" is negative, that means the tank is draining, so the Head-Pipe may be less than the Head-Gas due to headlosses.

See Also

Modeling Reference - Hydropneumatic Tanks
Determining the Headloss Coefficient for a hydropneumatic tank or surge tank