Westerman, JerryCelebioglu, KutayAyli, EceUlucak, OguzhanAradag, Selin06.06. Makine Mühendisliği06. Mühendislik Fakültesi01. Çankaya Üniversitesi2023-11-302025-09-182023-11-302025-09-182023Celebioglu, Kutay...et.al. (2023). "Critical decision making for rehabilitation of hydroelectric power plants", Energy Sources, Part A: Recovery, Utilization and Environmental Effects, Vol.45, No.4, pp.10073-10106.1556-70361556-7230https://doi.org/10.1080/15567036.2023.2241409https://hdl.handle.net/20.500.12416/13246Ulucak, Oguzhan/0000-0002-2063-2553Due to their diminishing performance, reliability, and maintenance requirements, there has been a rise in the demand for the restoration and renovation of old hydroelectric power facilities in recent decades. Prior to initiating a rehabilitation program, it is crucial to establish a comprehensive understanding of the power plant's current state. Failure to do so may result in unnecessary expenses with minimal or no improvements. This article presents a systematic rehabilitation methodology specifically tailored for Francis turbines, encompassing a methodological approach for condition assessment, performance testing, and evaluation of rehabilitation potential using site measurements and CFD analysis, and a comprehensive decision-making process. To evaluate the off-design performance of the turbines, a series of simulations are conducted for 40 different flow rate and head combinations, generating a hill chart for comprehensive evaluation. Various parameters that significantly impact the critical decision-making process are thoroughly investigated. The validity of the reverse engineering-based CFD methodology is verified, demonstrating a minor difference of 0.41% and 0.40% in efficiency and power, respectively, between the RE runner and actual runner CFD results. The optimal efficiency point is determined at a flow rate of 35.035 m(3)/s, achieving an efficiency of 94.07%, while the design point exhibits an efficiency of 93.27% with a flow rate of 38.6 m(3)/s. Cavitation is observed in the turbine runner, occupying 27% of the blade suction area at 110% loading. The developed rehabilitation methodology equips decision-makers with essential information to prioritize key issues and determine whether a full-scale or component-based rehabilitation program is necessary. By following this systematic approach, hydroelectric power plants can efficiently address the challenges associated with aging Francis turbines and optimize their rehabilitation efforts.eninfo:eu-repo/semantics/closedAccessReverse EngineeringCfdFrancis TurbinePerformance EstimationTransient SimulationArticle10.1080/15567036.2023.22414092-s2.0-85167360810