Experimental study of pressure pulsations in the flow duct of a medium-size model hydroelectric generator with Francis turbine

2018 ◽  
Vol 25 (1) ◽  
pp. 21-30 ◽  
Author(s):  
D. V. Platonov ◽  
A. V. Maslennikova ◽  
D. A. Dekterev ◽  
A. V. Minakov ◽  
A. V. Abramov
Keyword(s):  
Experimental Study ◽  
Francis Turbine ◽  
Medium Size ◽  
Pressure Pulsations ◽  
Hydroelectric Generator ◽  
Size Model ◽  
Flow Duct

scholarly journals Numerical study of a case of the free discharge of water through the turbine with a braked runner

2021 ◽  
Vol 2119 (1) ◽  
pp. 012152
Author(s):  
D V Platonov ◽  
A V Minakov ◽  
A V Sentyabov
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Numerical Study ◽  
Francis Turbine ◽  
Flow Structures ◽  
Pressure Pulsations ◽  
Integral Characteristics ◽  
Free Discharge ◽  
Simulation Results ◽  
Volume Method

Abstract The paper presents a numerical study of the free discharge of water through the turbine with a braked runner. The simulation was carried out for a unit of a full-scale Francis turbine. The finite volume method was employed for unstructured meshes using the DES method. The simulation results show the flow structures, integral characteristics, and pressure pulsations in the flow path. The analysis of the applicability of this approach to real conditions is carried out.

Comparison of Axial Water and Air Injections in the Draft Tube of a Francis Turbine for RVR Mitigation

2021 ◽  
Author(s):  
Subodh Khullar ◽  
Krishna M. Singh ◽  
Michel J. Cervantes ◽  
Bhupendra K. Gandhi
Keyword(s):  
Pressure Pulsation ◽  
Draft Tube ◽  
Water Injection ◽  
Air Injection ◽  
Flow Instabilities ◽  
Pressure Recovery ◽  
Francis Turbine ◽  
Tube Flow ◽  
Pressure Pulsations ◽  
Jet Injection

Abstract The presence of excessive swirl at the runner outlet in Francis turbines operating at part load leads to the development of flow instabilities such as the rotating vortex rope (RVR). The presence of RVR causes severe pressure pulsations, power swings, and fatigue damage in the turbine unit. Air and water injection in the draft tube have been reported to reduce the detrimental effects of RVR formation in the Francis turbines. Air injection is one of the oldest and most widely used methods. In contrast, water jet injection is a relatively new methodology. The present work reports the numerical simulations performed to compare the respective effectiveness of these methods to mitigate the RVR and the related flow instabilities. The efficacy of the two methods has been compared based on the pressure pulsations and pressure recovery in the draft tube cone. The results show that the air and water injection influence the draft tube flow field in different ways. Both air and water injection led to a reduction in pressure pulsation magnitudes in the draft tube cone. However, the air injection led to a negative pressure recovery while the water injection improved the draft tube action.

The numerical simulation of low frequency pressure pulsations in the high-head Francis turbine

2015 ◽  
Vol 111 ◽  
pp. 197-205 ◽  
Author(s):  
A.V. Minakov ◽  
D.V. Platonov ◽  
A.A. Dekterev ◽  
A.V. Sentyabov ◽  
A.V. Zakharov
Keyword(s):  
Numerical Simulation ◽  
Low Frequency ◽  
Francis Turbine ◽  
Pressure Pulsations ◽  
High Head

Experimental Study on Neotype Anchor System in Tower of Cable-Stayed Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 2017-2022
Author(s):  
Dong Lian Tan ◽  
Feng Jiang Qin ◽  
Di Jin
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Full Size ◽  
Anchor System ◽  
Good Working ◽  
Cable Stayed Bridge ◽  
Size Model ◽  
Test Investigation ◽  
The Cost ◽  
Cost Of Construction

Concrete is used in tower, and steel is used in anchor zone. It can make full use of the two materials’ nature. It can not only satisfy the tower’s stressed aptitude, but also can reduce the cost of construction. In this paper, the full size model has been designed and constructed. The test investigation of the statical performance have been proceeded. The results show that the neotype anchor system can make full use of the materials’ nature and is in good working order. The anchor system with enough bearing capacity satisfies the operating requiements of the cable-stayed bridge.

scholarly journals 3D unsteady turbulent flow analysis in a Francis turbine runner at nominal and off-design operating conditions

2004 ◽  
Vol 26 (3) ◽  
pp. 148-156
Author(s):  
Pham Thi Kim Loan ◽  
Bui Van Ga
Keyword(s):  
Turbulent Flow ◽  
Flow Analysis ◽  
Operating Conditions ◽  
Design Flow ◽  
Francis Turbine ◽  
Navier Stokes ◽  
Medium Size ◽  
Turbine Runner ◽  
Design Values ◽  
Physical Phenomena

This paper presents the use of a commercial Navier-Stokes turbulent flow code (FLUENT) as a mean to evaluate the behavior of a Francis turbine runner for the design and off-design conditions. The flow in the runner is analyzed numerically at different operating points. The numerical results permit to observe physical phenomena in the runner that are important in the process of hydraulic turbo machinery design. Values of different velocity components in the flow, blade pressure distribution ... given by the model are compared with experimental data at nominal and off-design flow conditions. Computer resource involves in the flow analysis should be compatible with the need of design process of a runner. Therefore 12 hours of CPU time can be considered as acceptable for calculating at each operating point on a computer workstation of medium size power.

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