The analysis of unsteady flow structure and low frequency pressure pulsations in the high-head Francis turbines

2015 ◽  
Vol 53 ◽  
pp. 183-194 ◽  
Author(s):  
A.V. Minakov ◽  
D.V. Platonov ◽  
A.A. Dekterev ◽  
A.V. Sentyabov ◽  
A.V. Zakharov
Keyword(s):  
Unsteady Flow ◽  
Flow Structure ◽  
Low Frequency ◽  
Pressure Pulsations ◽  
High Head

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

Use of Methods of Mathematical Modeling to Analyze Low-Frequency Pressure Pulsations in the Continuous Run of High-Head HPP

2015 ◽  
Vol 49 (2) ◽  
pp. 90-97 ◽  
Author(s):  
A. V. Minakov ◽  
D. V. Platonov ◽  
A. A. Dekterev ◽  
A. V. Sentyabov ◽  
I. M. Pylev ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Low Frequency ◽  
Pressure Pulsations ◽  
High Head

scholarly journals Analysis of Flow Instabilities on a Three-Bladed Axial Inducer in Fixed and Rotating Frames

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Giovanni Pace ◽  
Dario Valentini ◽  
Angelo Pasini ◽  
Ruzbeh Hadavandi ◽  
Luca d'Agostino
Keyword(s):  
Low Frequency ◽  
Flow Instabilities ◽  
Test Facility ◽  
Pressure Measurements ◽  
Dynamic Characterization ◽  
Rotating Frames ◽  
Induced Flow ◽  
High Head ◽  
Pump Inlet

The paper describes the results of recent experiments carried out in the Cavitating Pump Rotordynamic Test Facility for the dynamic characterization of cavitation-induced flow instabilities as simultaneously observed in the stationary and rotating frames of a high-head, three-bladed axial inducer with tapered hub and variable pitch. The flow instabilities occurring in the eye and inside the blading of the inducer have been detected, identified, and monitored by means of the spectral analysis of the pressure measurements simultaneously performed in the stationary and rotating frames by multiple transducers mounted on the casing near the inducer eye and on the inducer hub along the blade channels. An interaction between the unstable flows in the pump inlet and in the blade channels during cavitating regime has been detected. The interaction is between a low frequency axial phenomenon, which cyclically fills and empties each blade channel with cavitation, and a rotating phenomenon detected in the inducer eye.

Numerical analysis of unsteady flow under high‐head operating conditions in Francis turbine

2010 ◽  
Vol 27 (3) ◽  
pp. 365-386 ◽  
Author(s):  
Xiao Yexiang ◽  
Wang Zhengwei ◽  
Yan Zongguo ◽  
Li Mingan ◽  
Xiao Ming ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Unsteady Flow ◽  
Operating Conditions ◽  
Francis Turbine ◽  
High Head

Monitoring the parameters of a reactor by low-frequency pressure pulsations

1981 ◽  
Vol 51 (2) ◽  
pp. 512-516
Author(s):  
V. I. Vlasov ◽  
S. A. Mokrushin ◽  
V. P. Radchenko ◽  
V. V. Selin ◽  
A. A. Artamonov ◽  
...  
Keyword(s):  
Low Frequency ◽  
Pressure Pulsations

scholarly journals Flow regimes in a multi-gap circular Couette-Taylor system with opposite rotating cylinders

2021 ◽  
Vol 2119 (1) ◽  
pp. 012103
Author(s):  
A F Serov ◽  
V N Mamonov ◽  
A D Nazarov ◽  
N B Miskiv
Keyword(s):  
Flow Structure ◽  
Low Frequency ◽  
Working Fluid ◽  
Frequency Spectra ◽  
Initial Information ◽  
Heat Generator ◽  
Working Space ◽  
Resistance Torque ◽  
Hydrodynamic Processes ◽  
Circular Space

Abstract This work investigates the flow structure in the gaps of a multi-cylinder circular Couette-Taylor system, which is a model of a two-rotor heat generator. The initial information for studying the flow structure was data on the magnitude of the resistance torque to rotors opposed rotation, as well as on the nature of the amplitude-frequency spectrum of pulsations of this torque, depending on the viscosity of the working fluid and the rotational speed of the heat generator rotors. The obtained data allow comparing the nature of hydrodynamic processes in the single and obtained multi-gap circular space of Couette-Taylor and calculating the parameters of structural formations in the multi-gap working space of the heat generator. At relative rotational speeds of rotors (3-50) rad/s, the main energy of flow pulsations (up to 90%) is found in the amplitude-frequency spectra in the frequency range (12-70) Hz. It is associated with vortices first described by Taylor, which are extended low-frequency regularly alternating spirals and vortex structures with right and left rotation in the region of higher frequencies (200– 500) Hz; their frequency is determined by the width of the annular gaps of the multi-cylinder system.

scholarly journals Numerical and physical study of transitions to unsteady modes of melt flow with the Prandtl number 16 in the Czochralski method

2021 ◽  
Vol 2119 (1) ◽  
pp. 012165
Author(s):  
V S Berdnikov ◽  
V A Vinokurov ◽  
V V Vinokurov
Keyword(s):  
Heat Transfer ◽  
Prandtl Number ◽  
Unsteady Flow ◽  
Flow Structure ◽  
Characteristic Temperature ◽  
Temperature Drop ◽  
Czochralski Method ◽  
Melt Flow ◽  
Flow And Heat Transfer ◽  
Physical Study

Abstract The evolution of the flow structure and heat transfer with an increase in the characteristic temperature drop in the ranges of Grashof and Marangoni numbers 3558 ≤ Gr ≤ 7116 and 2970 ≤ Ma ≤ 5939 are investigated numerically. The boundary of the transition to unsteady flow and heat transfer regimes has been determined.

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