Numerical Modeling of Water Hammer Phenomenon in Hydropower Pipelines - A Case Study of Keyal Khawar Hydropower Plant

Abstract:

This study aimed at development and application of a numerical model; WHPANM (Water Hammer Phenomenon Analysis Numerical Model), to investigate the water hammer phenomenon in the penstock of the Keyal Khawar hydropower plant in Khyber Pakhtunkhwa, Pakistan. The model, written in Visual Basic, utilized the numerical method of characteristics to solve the momentum and continuity water hammer equations. Results indicated that using a 2.2 m diameter pipe resulted in a maximum and minimum pressure head of 1462 m and 1420 m. Increasing the diameter to 3.0 m decreased the maximum pressure head to 1448 m, while the minimum pressure head increased to 1422 m. Conversely, decreasing the diameter to 1.0 m led to a maximum and minimum pressure head of 1522 m and 1363 m, respectively. Regarding pipe length, a standard length of 900 m maintained maximum and minimum pressure heads at 1462 m and 1420 m, respectively. Extending length to 1400 m increased maximum pressure head to 1485 m. Conversely, shortening length to 300 m resulted in a decreased maximum pressure head of 1436 m, with minimum pressure head remaining constant at 1420 m. To prevent water hammer damage in high head hydropower plants, study recommends utilizing a 2.2 m diameter penstock pipe and coordinating valve closure times accordingly. The study suggests a systematic design approach, optimal penstock diameter, and less rigid pipe materials to mitigate water hammer effects. The WHPANM model demonstrated strong concordance with the original data generated by the commercial software employed by the consultant for the Kyal Khwar hydropower plant.

• Periodical: Construction Technologies and Architecture (Volume 13)
• Pages: 85-93
• DOI: https://doi.org/10.4028/p-2mes8O
• Online since: July 2024
• Authors: Muhammad Aslam, Ahsan Ali, Muhammad Kaleem Ullah, Muhammad Shafqat Ejaz, Bisma Khalid*, Rana Sharjeel Ayaz
• Keywords: Keyal Khawar Hydropower Plant, Numerical Model, Penstock, Visual Basic, Water Hammer

References

[1] N. Bettaieb and E. H. Taieb, "Assessment of failure modes caused by water hammer and investigation of convenient control measures," Journal of Pipeline Systems Engineering and Practice, vol. 11, no. 2, p.04020006, 2020.

DOI: 10.1061/(asce)ps.1949-1204.0000446

[2] L. Zhao et al., "An experimental study on the water hammer with cavity collapse under multiple interruptions," Water, vol. 12, no. 9, p.2566, 2020.

DOI: 10.3390/w12092566

[3] R. Bagaragaza, "Investigation on hydraulic transient flow in hydropower station with air chamber and pressure relief valve," Hohai University, 2017.

[4] A. Adamkowski, M. Lewandowski, and S. Lewandowski, "Fatigue life analysis of hydropower pipelines using the analytical model of stress concentration in welded joints with angular distortions and considering the influence of water hammer damping," Thin-Walled Structures, vol. 159, p.107350, 2021.

DOI: 10.1016/j.tws.2020.107350

[5] S.-I. Lupa, M. Gagnon, S. Muntean, and G. Abdul-Nour, "The impact of water hammer on hydraulic power units," Energies, vol. 15, no. 4, p.1526, 2022.

DOI: 10.3390/en15041526

[6] M. A. Çetintaş, "Investigation of interaction between pressure relief valve and turbines during a transient flow in hydropower plant," Middle East Technical University, 2022.

[7] R. Kausar, H. Farid, and M. Riaz, "A numerically validated approach to modeling water hammer phenomena using partial differential equations and switched differential-algebraic equations," J. Ind. Intell, vol. 1, no. 2, pp.75-86, 2023.

DOI: 10.56578/jii010201

[8] R. Bagaragaza et al., "Hydrodynamic Analysis Of Water Hammer Phenomena In Hydropower Stations Under Turbine Extreme Operating Conditions," Global Journal of Pure and Applied Sciences, vol. 30, no. 1, pp.73-87, 2024.

DOI: 10.4314/gjpas.v30i1.7

[9] T. W. Choon, L. K. Aik, L. E. Aik, and T. T. Hin, "Investigation of water hammer effect through pipeline system," International Journal on Advanced Science, Engineering and Information Technology, vol. 2, no. 3, pp.246-251, 2012.

DOI: 10.18517/ijaseit.2.3.196

[10] A. Triki, "Water-hammer control in pressurized-pipe flow using an in-line polymeric short-section," Acta Mechanica, vol. 227, no. 3, pp.777-793, 2016.

DOI: 10.1007/s00707-015-1493-1

[11] H. Cao, M. Mohareb, and I. Nistor, "Finite element for the dynamic analysis of pipes subjected to water hammer," Journal of Fluids and Structures, vol. 93, p.102845, 2020.

DOI: 10.1016/j.jfluidstructs.2019.102845

[12] A. Keramat, A. Tijsseling, Q. Hou, and A. Ahmadi, "Fluid–structure interaction with pipe-wall viscoelasticity during water hammer," Journal of Fluids and Structures, vol. 28, pp.434-455, 2012.

DOI: 10.1016/j.jfluidstructs.2011.11.001

[13] R.K. Garg and A. Kumar, "Experimental and numerical investigations of water hammer analysis in pipeline with two different materials and their combined configuration," International Journal of Pressure Vessels and Piping, vol. 188, p.104219, 2020.

DOI: 10.1016/j.ijpvp.2020.104219

[14] C. C. Warnick and H. A. Mayo Jr, Hydropower engineering. 1984.