Hydraulic turbines have become indispensable for harnessing renewable energy sources, particularly in-pipe hydraulic turbine technology, which leverages excess energy within pipeline systems like drinking water distribution pipes to produce electrical power. Among these turbines, the propeller-type axial turbine with circular blades stands out for its efficiency. However, there is a notable lack of literature on fluid dynamics and structural behavior under various operational conditions. This study introduces a comprehensive methodology to numerically investigate the hydraulic and structural responses of turbines designed for in-pipe installation. The methodology encompasses the design of circular blades, followed by parametric studies on fluid dynamics and structural analysis. The circular blade’s performance was evaluated across different materials, incorporating static, modal, and harmonic response analyses. Results showed that the circular blade achieved a peak hydraulic efficiency of 75.5% at a flow rate of 10 l/s, generating 1.86 m of head pressure drop and 138 W of mechanical power. Structurally, it demonstrated a safety factor exceeding 1 across the entire hydraulic range without encountering resonance or fatigue issues. This research and its methodology significantly contribute to advancing the understanding of designing and assessing the fluid dynamic behavior and structural integrity of circular blades in axial propeller-type turbines for in-pipe installations, serving as a valuable resource for future studies in similar domains.

A pump as turbine (PAT) is a turbomachine that converts hydraulic energy into electricity. One of the study topics in PAT is the efficiency due to centrifugal pumps are not designed to operate in reverse mode. Geometric variations of the impeller have been studied in the literature. However, it was not possible to evidence the influence of the inclination of the blade leading and trailing edge. Therefore, the objective of this work is to analyze numerically and fluid dynamically the inclination angle of the blade leading and trailing edge of a centrifugal pump, in pump and turbine mode. First, the characteristic curve was validated. Then, the inclination of the leading and the trailing edge was modified, in a range of 25° to 90°, obtaining head, efficiency, and power graph. As a result, in pump mode was evidenced that an angle close to 90° on the blade trailing edge provides a higher efficiency of 50.26% and decreases until 40.77% when the angle approaches 30°, reducing the head to around 20%, while power remained constant. In turbine mode, an inverse effect was obtained, where the maximum efficiency was 60.9% and the generated power increased up to 4.76 kW in the blade leading edge. Therefore, the angular variation of the leading and the trailing edge is adequate in turbine mode, while in pump mode there is a loss of capacity.

This paper presents the mathematical modeling, fluid dynamic analysis, and experimental analysis of a spiral case without guide vanes. Using a specific case of the Archimedes spiral, the model eliminates the need for fixed or moving blades to simplify the design, manufacturing, and maintenance process of the turbomachine by reducing the number of system components while preserving the fluid dynamic performance of a turbomachine operating in turbine mode. The potential flow theory is used as a mathematical basis for developing a computational code that allows the automatic generation of the curves that define the geometry of the spiral chamber, simplifying the CAD modeling process. Finally, the process is validated numerically and experimentally under different operating conditions, reaching an average error percentage between numerical and experimental analysis of 5.893% of speed and 11.089% of pressure, guaranteeing the accuracy of the model.

In this study, statistical analysis and computational fluid dynamics (CFD) were employed to study the efficiency and self-starting trade-off of a Savonius–Darrieus hybrid turbine. The research focused on identifying the optimal radius ratio, coupling angle, tip–speed ratio and azimuth angle to maximize static moment. CFD simulations were conducted in ANSYS 2024 R1 to calculate the static moment for each configuration. These results were analyzed to determine the standardized effects, main effects, and variance, identifying the impact of each variable on performance. Following the statistical analysis, five regression models were proposed to predict self-starting capability, with the fifth model ($ms5$) demonstrating the highest goodness-of-fit. This model was optimized using a response volume visualization, where the study variables were mapped against a static moment color gradient. Iteration of the $ms5$ model revealed that an optimal arrangement of 0.8 (radius ratio), 102° (coupling angle), and 45° (azimuth angle) yielded a static moment of 173.59 Nm, surpassing all initial DOE results. A comparative analysis showed that the standalone Darrieus and Savonius static moments were 93.18% and 26.74% lower, respectively, than the optimized hybrid value. The reported static moment characterizes the rotor’s tendency to initiate rotation from rest; it does not constitute a dynamic start-up simulation. Furthermore, the integrated self-starting and efficiency model allowed the identification of a balanced configuration between efficiency and static moment, consisting of a radius ratio of 0.37, a coupling angle of 104°, a TSR of 2.2, and an azimuthal angle of 43°. This case was numerically simulated to verify its performance, resulting in an efficiency of 48.97% and a static moment of 35.46 Nm, respectively.

Las condiciones de pandemia han llevado a la educación a buscar formas alternativas de llegar a los estudiantes con un proceso formativo similar a las condiciones de la presencialidad. Existen muchas herramientas virtuales para el aprendizaje a través de aplicativos webs, pero estos medios no reemplazan la interacción con los equipos reales. Las herramientas tecnológicas deben ser exploradas a profundidad de tal forma que permitan generar una experiencia cercana con los equipos de laboratorio. Por esta razón, en este artículo se presenta una propuesta metodológica para repotenciar laboratorios disponibles en instituciones universitarias, facilitando el acceso remoto a los dispositivos. Esta metodología integra la experiencia pedagógica y tecnológica de docentes y estudiantes y es implementada en un equipo de aire acondicionado del laboratorio de fluidos del Instituto Tecnológico Metropolitano (ITM) de Medellín.