Maximum Water Hammer Sensitivity Analysis

Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of each input parameter of the application relative to the maximum amount of water hammer estimated by the software. The study determines estimated maximum water hammer variations due to variations of input parameters including water temperature, pipe type, thickness and diameter, electromotor rpm and power, and moment of inertia of electromotor and pump. In our study, Kuhrang Pumping Station was modeled using WaterGEMS Software. The pumping station is characterized by total discharge of 200 liters per second, dynamic height of 194 meters and 1.5 kilometers of steel conveyance pipeline and transports water to Cheshme Morvarid for farmland irrigation. The model was run in steady hydraulic condition and transferred to Hammer Software. Then, the model was run in several unsteady hydraulic conditions and sensitivity of maximum water hammer to each input parameter was calculated. It is shown that parameters to which maximum water hammer is most sensitive are moment of inertia of pump and electromotor, diameter, type and thickness of pipe and water temperature, respectively.

Authors:

• Jalil Emadi
• Abbas Solemani

Keywords:

• Pressure Wave
• Water Hammer
• Sensitivity Analysis
• Hammer Software
• Kuhrang
• Cheshme Morvarid

References:

[1] Ashofte, Jalal and Pezeshkirad, Alireza (1994), Hydraulic Application
of Transient Waves, 1st Volume, 1st edition, Kabiri Publication Co.
[2] Cukier R., Levine H., Shuler K., Nonlinear sensitivity analysis of
multiparameter model systems, Journal of Computational Physics,
1978, Vol. 26, pp. 1-42.
[3] Saltelli A., Tarantola S., Chan P.S., A quantitative modelindependent
method for global sensitivity analysis of model output,
Technometrics, 1979, Vol. 41(1), pp. 39-56.
[4] Glaeser H. G., Uncertainty evaluation of thermal-hydraulic code
results, Int. Meeting on "Best-Estimate" Methods in Nuclear
Installation Safety Analysis (BE-2000), Washington, D.C., USA,
2000.
[5] Saltelli A., Making best use of model evaluations to compute
sensitivity indices, Computer Physics Communications, 2002, Vol.
145(2), pp. 280-297.
[6] Kaliatka A., Ušpuras E., Vaišnoras M., Uncertainty and sensitivity
analysis of water hammer phenomenon by employing the UMSICHT
test facility data, Proceedings of 11th International Topical Meeting
on Nuclear Reactor Thermal Hydraulics (NURET H-11), October 2-
6, 2005, Avignon, France, pp. 1-12.
[7] Kaliatka A., Ušpuras E., Vaišnoras M., Uncertainty and sensitivity
analysis of parameters affecting water hammer pressure wave
behaviour, Kerntechnik, 2006, Vol. 71, No. 5-6, pp. 270-278.
[8] Kaliatka, A., Kopustinskas V., Vaišnoras M., Water hammer model
sensitivity study by the FAST method, Energetika, 2009, T. 55, Nr. 1,
pp. 13-19.
[9] http://www.haestad/Hammer User's Guide
[10] Neshan, Hamidreza, Water Hammer, 1st Edition, Publication of Pump
Manufacturing Industries Company, Tehran, Iran,
1985.http://www.mechanicab.com
[11] Wylie E. B., Streeter V. L., Suo L., Fluid Transients in Systems,
Prentice-Hall Inc., Englewood Cliffs, New Jersey, USA, 1993.