This paper introduces a conceptual framework for the development and implementation of a digital twin specifically designed for the Wały Śląskie Hydroelectric Power Plant. The primary focus is on defining the digital twin concept, addressing critical challenges encountered during its conceptualization, such as incomplete plant documentation, limited real-time data availability, and complexities in system integration. The digital twin architecture developed to address these issues features modular components, including data acquisition, data processing, visualization, and integration layers, emphasizing scalability, adaptability, and secure interoperability. Computational Fluid Dynamics (CFD) simulations and AI-based modeling techniques are integrated into the proposed framework as essential tools, providing critical data inputs for efficiency modeling and operational analysis. The proposed digital twin concept ensures accurate and reliable digital representation, facilitating informed decision-making and efficient operational management within hydropower plants.

Water hammer is a critical transient phenomenon in pumping systems, occurring when a sudden change in flow velocity generates pressure waves propagating along the pipeline. This study focuses on the dynamic response of a long rising pipeline subjected to an emergency pump shutdown, with particular emphasis on the sudden release and propagation of hydraulic energy in the form of pressure waves. Such scenarios are typical for mine dewatering and water supply systems with high elevation differences. Two numerical approaches were investigated: the Method of Characteristics (MOC) implemented in TSNet as a reference model, and the Train Analogy Method (PKP) implemented in MATLAB R2024b/Simulink, where the fluid is represented as discrete masses connected by elastic links, enabling the inclusion of pump and motor dynamics. Simulations were performed for two configurations: first–with a check valve installed only at the pump discharge and second–with a check valve at the pump discharge and in the middle of the pipeline. The results demonstrate that both models capture the essential features of water hammer: a sharp initial pressure drop, the formation of transient waves, and pressure oscillations with decreasing amplitude. These oscillations reflect the propagation and gradual dissipation of hydraulic energy stored in the moving fluid, primarily due to frictional and elastic effects within the pipeline. The presence of a check valve accelerates the attenuation of oscillations, effectively reducing the impact of returning waves on the downstream pipeline. The novelty of this study lies in the use of the PKP method to simulate transient flow and energy exchange in long rising pipelines with dynamic pump behavior. The method offers a physically intuitive and modular approach that enables the modelling of local flow phenomena, pressure wave propagation, and system components such as pump–motor inertia and check valves. This makes PKP a valuable tool for investigating complex water hammer scenarios, as it enables the analysis of pressure wave propagation and damping, providing insight into the scale and evolution of energy released during sudden operational incidents, such as an emergency pump shutdown. The close agreement between the PKP and MOC results confirms that the PKP method implemented in Simulink is a reliable tool for predicting transient pressure behavior in hydraulic installations and supports its use for further validation and dynamic system analysis.

Developing digital twins for legacy hydropower units is difficult when turbine documentation, calibrated performance data, and integrated measurements are incomplete. This study presents a Computational Fluid Dynamics (CFD)-assisted reconstruction workflow for a Kaplan turbine at the Wały Śląskie Hydropower Plant and evaluates its use as a physics-informed foundation for a digital twin. The flow passage was reconstructed from archival documentation, direct measurements, and optical 3D scanning of the runner. A steady-state Reynolds-averaged Navier–Stokes model was then prepared in OpenFOAM v2506 for selected head levels, guide-vane openings, and runner-blade angles. The simulations determined hydraulic performance, flow-field structures, and combinatory characteristics of the double-regulated turbine. The computed hydraulic efficiency reached approximately 85% in the nominal-head range, and the highest-efficiency region formed a broad plateau rather than a sharp optimum. CFD-derived and measurement-derived combinatory trends were consistent, although absolute values remain limited by relative field measurements and uncalibrated Winter–Kennedy flow estimation, a differential-pressure-based method. The CFD results were reduced to compact response surfaces and integrated with reconstructed geometry into an advisory digital twin for operating-point assessment, visualization, documentation, and training. This study establishes a robust workflow for this specific Kaplan turbine case where reverse engineering, integrated with CFD analysis, generates high-fidelity surrogate models for hydropower digital twins, effectively addressing the challenge of incomplete legacy documentation.