Numerical simulation of fluid added mass effect on a francis turbine runner

2007 ◽  
Vol 36 (6) ◽  
pp. 1106-1118 ◽  
Author(s):  
Q.W. Liang ◽  
C.G. Rodríguez ◽  
E. Egusquiza ◽  
X. Escaler ◽  
M. Farhat ◽  
...  
2013 ◽  
Vol 456 ◽  
pp. 207-210
Author(s):  
Fang He

This paper presents a vibration prediction method for Francis turbine: Provided with advanced CFX software, Numerical simulation of movable guide vane and Turbine runner’s internal flow state. From the source of hydraulic vibration, Focus on numerical analysis, numerical simulation for the cutting thickness of the runner blade. After analysis of the influence of the blade of hydraulic vibration. To explore new ways for the hydro turbine control hydraulic vibration.


2020 ◽  
Vol 25 (1) ◽  
pp. 104-111
Author(s):  
Shahrokh Sepehrirahnama ◽  
Felix Bob Wijaya ◽  
Darren Oon ◽  
Eng Teo Ong ◽  
Heow Pueh Lee ◽  
...  

In this hydroelasticity study, the fluid added-mass effect on a hemispherical shell structure under flexural vibration is investigated. The vibration response of the hemisphere is solved by using a commercial finite element software (ABAQUS) coupled with an in-house boundary element code that models the fluid as potential flow. The fluid-structure interaction is solved as a fully-coupled system by modal superposition to reduce the number of degrees of freedom. The need for an iterative scheme to pass displacement/force information between the two solvers is avoided by direct coupling between the fluid and structure equations. The numerical results on the downward shift in natural frequencies due to added-mass effect compare well with vibration measurements conducted on a stainless-steel bowl with interior and exterior fluid. For water and soap-water solution used in the experiments, the fluid viscosity (varying over a wide range) did not have any significant effect on the wet natural frequencies. This is due to the small viscous boundary layer (milimetre scale) compared to the nominal size of the bowl in centimetres. For such cases, the fluid-added mass only depends on the density of the fluid and the use of potential flow in the numerical model is applicable.


2013 ◽  
Vol 2013 (0) ◽  
pp. _J027042-1-_J027042-5
Author(s):  
Daisuke ISHIHARA ◽  
Tomoyoshi HORIE ◽  
Tomoya NIHO

2019 ◽  
Vol 36 (2) ◽  
pp. 491-508 ◽  
Author(s):  
Lingyan He ◽  
Lingjiu Zhou ◽  
Soo-Hwang Ahn ◽  
Zhengwei Wang ◽  
Yusuke Nakahara ◽  
...  

Purpose The gaps between runner and nearby structures play an important role in the dynamic response of runner, especially for pump-turbines. This paper aims to evaluate the gap influence on the added mass and dynamic stress of pump-turbine runner and provide an improved method to predict the resonance of runner. Design/methodology/approach Acoustic-structural coupling method was used to evaluate the added mass factors of a reduced scale pump-turbine with different axial and radial gap size between runner and nearby rigid walls. Improved one-way fluid-structural interaction (FSI) simulation was used to calculate the dynamic stress of the runner, which takes into account fluid added mass effect. The time-dependent hydraulic forces on the runner surfaces that were obtained from unsteady CFD simulation were transferred to the runner structure as a boundary condition, by using mesh-matching algorithm at the FSI surfaces. Findings The results show that the added mass factors increase as the gap size decreases. The axial gaps have greater influence on the added mass factors for the in-phase (IP) modes than the counter-phase (CP) and crown-dominant (CD) modes, while the CP and CD modes are very sensitive to the radial gaps. The largest added mass factor is observed in (2 + 4)ND-CP mode (resonance mode). The results reveal that the transient structural dynamic stress analysis, with the consideration of gaps and fluid added mass, can accurately predict the resonance phenomenon. Resonance curve of the pump-turbine has been obtained which agrees well with the test result. The gap fluid has great influence on the resonance condition, while for non-resonance operating points, the effect of gaps on the dynamic stress amplitude is quite small. Originality/value This paper provides an accurate method to analyze the dynamic response during runner design stage for safety assessment. The resonance curve prediction has more significance than previous methods which predict the resonance of runner by modal or harmonic analysis.


2013 ◽  
Vol 860-863 ◽  
pp. 1521-1524
Author(s):  
Si Qing Zhang ◽  
Guo Hua Ma ◽  
Yun Long Zhang ◽  
Dong Wang

There are many difficulties to design, processing and research on numerical simulation for Francis turbine because of the complexity of blade shape and the difficulty of solid modeling. Based on two-dimensional wooden patterns of Francis turbine blades, this article aims to complete blades three-dimensional modeling for Francis turbine runner with long and short blades by means of Pro-E software which has powerful 3D modeling function. After comparing three kinds of available methods to generate blade across section which provided by Pro-E, finally completed blades three-dimensional modeling by method of generating across section with point files, established a smooth and accurate three-dimensional model. The method provides an accurate physical model for the numerical simulation of the Francis turbine with long and short blades, as well as provides a feasible approach for hydro-mechanical blades modeling.


2011 ◽  
Vol 130-134 ◽  
pp. 2594-2599
Author(s):  
Shu Cong Shang ◽  
Jian Zhong Sun

A dynamic model and numerical method which was in the underwater vertical launching process have been built, and the missile which was on the effects of the lateral flow was simulated with its movement and load. The results showed that: the model is feasible; adapter compressive stiffness and its layout in the tube has a greater impact on the movement and load of the missile; fluid added mass effect is not negligible; the lateral movement of the missile’s launching process was along with a large shock , so we must attach importance to the problem of vibration. lateral flow


2006 ◽  
Vol 22 (5) ◽  
pp. 699-712 ◽  
Author(s):  
C.G. Rodriguez ◽  
E. Egusquiza ◽  
X. Escaler ◽  
Q.W. Liang ◽  
F. Avellan

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