INVESTIGATION OF WATER HAMMER EFFECT ON THE TRANSMISSION MAIN PIPELINE OF SU’ULA -MANDA-DABA MULTI-VILLAGE WATER SUPPLY SCHEMES, AFARTHIOPIA,

Abstract

This thesis systematically analyzes water hammer issues in the transmission pipeline of the SMD (Su'ula-Manda-Daba) Multi-Village Water Supply Schemes in Afar, Ethiopia, with a focus on identifying, assessing, and mitigating transient flow problems through protective measures. It aims to rigorously evaluate the effectiveness of these measures in preventing water hammer effects and enhancing overall pipeline safety and performance. The study employs advanced simulation software, Bentley HAMMER version 8i, to model a range of scenarios, from routine system operations to unforeseen events like sudden pump failure. Findings reveal substantial reductions in system performance with protective measures. Scenario 1, without surge protection devices, exposes high-risk areas with extreme pressure spikes and negative pressures, underscoring the need for mitigation. Before safeguards, maximum pressure ranged from 266.16 m H₂O to 288.27 m H₂O at different pump stations, with minimum pressures as low as -9.98 m H₂O, accompanied by substantial cavitation. Scenario 2, with protective measures, demonstrates a remarkable transformation, with maximum pressures ranging from 121.38 m H₂O to 150.49 m H₂O, enhancing safety. Minimum pressures improved significantly, reaching levels of -2.37 m H₂O, -3 m H₂O, -3.66 m H₂O, and -2.45 m H₂O at respective pump stations. Notably, cavitation volumes were reduced to zero, affirming the protective measures' efficiency in maintaining system integrity and stability. Furthermore, Scenario 3 explores changing pipe materials and diameters, providing valuable insights for future pipeline design standards. To summarize, this study confirms the substantial effectiveness of protective measures in mitigating water hammer effects and highlights significant cost savings potential through the strategic use of 2000-liter hydro pneumatic tanks at pump stations, ultimately reducing the occurrence of pipeline collapses and associated maintenance costs.