A5078045536- Cavitation Phenomena in Pumps
- Hydraulic and Pneumatic Systems
- Vibration and Dynamic Analysis
- Electromagnetic Launch and Propulsion Technology
- Fluid Dynamics and Vibration Analysis
- Smart Grid Energy Management
- Fluid Dynamics and Turbulent Flows
- High-Voltage Power Transmission Systems
- Smart Grid and Power Systems
- Reservoir Engineering and Simulation Methods
- Cyclone Separators and Fluid Dynamics
- Oil and Gas Production Techniques
- Tribology and Lubrication Engineering
Universitat Politècnica de Catalunya
2022-2024
A Kaplan turbine unit from a new powerplant experienced high levels of vibrations and noise during the acceleration to nominal speed. These remained very at speed no load. first analysis seemed indicate possible blade resonance phenomenon as highest were measured on head cover. Nevertheless, after some modifications root blades, commissioning was delayed several months. To determine origin these vibrations, an array sensors installed in machine. Different types tests performed. Experimental...
Accurate determination of modal parameters for disk-like structures submerged in heavy fluids is a topic interest many fields. For instance, some type hydraulic turbomachinery can be modelled as disk due to the similarity their mode shapes. Although recent years studies have analyzed and correctly predicted fluid added mass effect on natural frequencies shapes these types structures, it particularly challenging determine damping characterize its most influential effects. In this article,...
To prevent lifetime shortening and premature failure in turbine runners, it is of paramount importance to analyse understand its dynamic response determine the factors that affect it. In this paper, a Kaplan runner analysed air by numerical experimental methods. First, start analysis mode shapes, geometry simplified modelled as bladed disk. Bladed disks with different blade numbers are investigated, simulation, order influence parameter on modal characteristics. Then, shapes extracted...
Pumped Storage Hydro (PSH) serves as a significant contributor to the transition toward net zero emissions, primarily due its capacity store large amounts of energy with very high round trip efficiency (RTE). This is especially important given volatility and unpredictability associated current mix, largely influenced by sources like wind solar. Managing these fluctuations poses operational challenges for pumped storage schemes.  Within EU's XFLEX project, various developments...
Abstract This work reports on a new Kaplan turbine that experienced an unstable behaviour during its start up. The unit strong sound and vibration in phase. To identify the origin of this behaviour, set sensors were installed within turbine. Subsequently, tests performed to determine response different acceleration machine speed no load stage. Following thorough analysis results, problem was identified as air admission openings head cover their distribution. address issue, reconfiguration...
Abstract Near-resonant flow-induced vibrations are a significant cause of fatigue damage in hydraulic impellers. The amplitude these is limited mainly by the fluid damping, making its quantification paramount for safety turbines. To study damping low-specific-speed radial impellers, submerged disc still water with variable vertical distance from rigid wall investigated. This setup serves as an abstraction axial gap between impeller hub and head cover, modal behavior impellers case...
Abstract The natural frequencies of a turbine can be calculated from numerical methods. By comparing these with excitation sources, one know the danger resonance and possible failure in component turbine. Therefore, it is often very important to have an accurate model determine frequencies. There are not many publications on determination reduced-scale models Kaplan turbines. More papers exist for pump turbines or Francis For real turbines, few experiments found mode shapes In this paper...
Abstract In order to satisfy the power demand in electrical grid, hydraulic turbine units frequently work under off-design operation conditions and pass through transient events. These can lead high vibration amplitudes runners, decreasing their useful life, some cases premature failures. To determine understand behaviour of fluid damping is a relevant topic, because this parameter limits maximum amplitude resonance conditions. The runner types turbines, such as reversible pump-turbine head...