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The two techniques, vibratory monitoring and pit counting, show promising results for the prediction of prototype cavitation erosion from model tests of Francis turbines. These cavitation detection methods are compared in two set-ups at different power lev ...
International Association For Hydraulic Research1994
In order to study the inlet and outlet cavitation in a Francis turbine (nq = 48) a numerical model of the bubble dynamics is established. By using the pressure and velocity distribution obtained by a 3-D potential flow analysis of the turbine, the Rayleigh ...
An experimental study of flow in a Francis hydraulic turbine, especially designed for the GAMM Workshop, has been carried out. In order to provide a data base for the validation and comparison of computational fluid dynamics codes, a Francis turbine mode! ...
An original validation of the vibratory approach of the cavitation erosion monitoring is presented. Cavitation induced vibrations on a given blade of a large hydro turbine are compared to vibrations induced at the lower guide bearing as well as to the pres ...
Stability of operation of Francis turbines Hydraulic disturbances often come with the operation of Francis turbines outside of design head and flow. In some cases, the excessive amplitude of the dynamic system response to these disturbances leads to res ...
Hydraulic turbine runners, which operate under a wide range of heads and outputs, are subjected to considerable dynamic forces at off design conditions. Therefore a detailed knowledge of mean and fluctuating pressures is required for a safe design of the r ...
International Association For Hydraulic Research2000
In this first part of a 2 papers series, we present the experimental procedure for onboard measurement of pressure and strain fluctuation in a model of low head Francis turbine. 28 miniature pressure sensors are fitted in the pressure and suction sides of ...
International Association For Hydraulic Research2002
In this second part of a 2 papers series, we present the analysis of “onboard” measurements on the runner of a Low Head Francis model and comparison with the same type of measurements on a similar prototype, as well as a comparison with numerical calculati ...
International Association For Hydraulic Research2002
Experimental studies have shown that outlet cavitation of a Francis turbine is influenced by the active nuclei content of the test loop water, up to a limit curve called the saturation characteristic. To determine the importance of this influence in operat ...
International Association For Hydraulic Research1992
Three dimensional numerical tools are now commonly used in the design or analysis process of the internai flow of hydraulic machinery. As an illustration of the use of such tools to study the internai flow of a Francis turbine, the computational results ob ...
International Association For Hydraulic Research1994