scholarly journals Flow-Induced Vibration on the Control Valve with a Different Concave Plug Shape Using FSI Simulation

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Akram Zeid ◽  
Mohamed Shouman
Keyword(s):  
High Efficiency ◽  
Complex Structure ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Control Valve ◽  
Low Noise ◽  
Flow Induced Vibration ◽  
Nonlinear Characteristics ◽  
Flow Phenomena

Control valves have always been recognised as being among the most crucial control equipment, commonly utilised in versatile engineering applications. Hence, the need has arisen to identify the flow characteristics inside the valve, together with the incurred vibration induced as a result of the flow passing through the valve. Thanks to the tangible and fast progress made in the field of the flow simulation and numerical techniques, it has become possible to better observe the behavior of the flow passing inside a valve with view to examining its performance. Hence, the paper at hand is mainly concerned with introducing the modeling and simulation of a control valve. On the contrary, the flow system in a control valve is marked by a complex structure and nonlinear characteristics. The reasons for those qualities could be attributed to its construction as well as the fluid flow phenomena associated with it. It is especially for the sake of investigating and observing the flow characteristics, pertaining to a control valve equipped with different concave plug shapes and different openings, that the three-dimensional FSI simulation is conducted. In addition, it would be possible to make use of the obtained results relating to the three-dimensional analysis to achieve low noise and high efficiency improvement. Furthermore, all results will be validated on experimental grounds.

A Numerical and Experimental Methodology to Characterize the Gaseous Cavitation in Spool Valves with U-notches

2021 ◽  
Author(s):  
Emma Frosina ◽  
Gianluca Marinaro ◽  
Amedeo Amoresano ◽  
Adolfo Senatore
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Control Valve ◽  
Experimental Methodology ◽  
Area Of Interest ◽  
Sound Levels ◽  
Directional Control ◽  
Upstream Pressure ◽  
Spool Valves

Abstract The performance of spool valves can deteriorate and noise can occur due to cavitation. The noise sound levels caused by cavitation are influenced by many parameters, among which the most important is not-optimal geometry of components. In this paper, a 2 ways - 2 positions directional control valve was studied using experimental and numerical approaches. Tests were performed on a plexiglass body and steel spool analyzing the cavitating area that develops in U-notches. A dedicated test rig was equipped with a high-speed camera placed directly in front of the area of interest where cavitation occurs. Different working conditions were tested by varying the upstream pressure to encourage the development of cavitation. Images were acquired and post-processed, focusing the contour extraction between the liquid and gaseous phases. The images were compared with results from three-dimensional CFD numerical simulations performed using commercial software. The numerical estimation of flow characteristics corroborated the results from investigations carried out using a fast camera, including periodic cavitation structures. This study demonstrates the importance and usefulness of using a three-dimensional CFD approach during the prototyping phase to create quieter component designs.

Three-Dimensional Vaneless Diffuser Rotating Stall Numerical Study

2018 ◽  
Author(s):  
Filip Grapow ◽  
Grzegorz Liśkiewicz
Keyword(s):  
Mass Flow ◽  
High Efficiency ◽  
Numerical Study ◽  
Complex Structure ◽  
Sudden Change ◽  
Three Dimensional ◽  
Rotating Stall ◽  
Frequency Change ◽  
Vaneless Diffuser ◽  
Growth Pressure

Abstract Centrifugal compressor efficiency is the key to increasing incomes from its operation. There are several flow instabilities which can negatively affect a compressor, one of them being the rotating stall, as it decreases efficiency and mass flow while it can also lead to a surge. Among others, this can occur in the vaneless diffuser. A thorough understanding of this phenomenon and the ability to model its behaviour can lead to a robust protection system assuring high efficiency even at lower mass flow rates. In this paper, the simulated flow was viscous and compressible. Much attention was devoted to providing boundary conditions that would not affect flow conditions at the diffuser outlet. The transient simulation was conducted in order to observe sequential stages of the VDRS onset and growth. Pressure signals from different points in the diffuser have been analysed with the CWT method in the purpose of detecting oscillations frequency change in time. Results have shown that the complex structure and time evolution of the VDRS indeed require the application of three-dimensional methods. As the mass flowrate was continuously decreased a sudden change in number of the rotating stall cells was observed together with an appearance of new strong peak of the pressure oscillation.

Effect of Baffles in Between Stages on Performance and Flow Characteristics of a Two-Stage Split Case Centrifugal Pump

2017 ◽  
Author(s):  
Yiyun Wang ◽  
Ji Pei ◽  
Shouqi Yuan ◽  
Wenjie Wang
Keyword(s):  
Centrifugal Pump ◽  
High Efficiency ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Production Method ◽  
Navier Stokes ◽  
Centrifugal Pumps ◽  
Two Stage

Two-stage split case centrifugal pumps play an important role in large flow rate and high lift water transfer situations. To investigate the influence of baffles in between stages on the performance and internal flow characteristics, the unsteady simulations for the prototype pump were carried out by solving the three-dimensional Reynolds-averaged Navier-Stokes equations with a shear stress transport (SST) turbulence model. The structured grids were generated for the whole flow passage. The calculated performance results were verified by the experimental measurements. The entropy production method based on numerical simulation was applied to analyze the distribution and mechanism of flow losses. The results show that the turbulence dissipation is the dominant flow loss, and the viscous dissipation can be neglected. The baffles can reduce the turbulence dissipation power obviously and can improve the hydraulic efficiency by maximum 5%, especially under QBEP and over-load conditions. The baffles have the greatest effect on the hydraulic losses in the double suction impeller., because they change the flow characteristics in the channels between the first stage impeller and the double suction impeller, affecting the inflow condition dramatically for the impeller. The study can give a reference to optimize the design of the two-stage split case centrifugal pump for high efficiency.

The Three-Dimensional Unsteady Numerical Analysis of the Internal Flow Field of the New Control Valve

2014 ◽  
Vol 980 ◽  
pp. 112-116
Author(s):  
Dong Yue Qu ◽  
Jia Lei Xu ◽  
Yang Yang Huang ◽  
Xiao Zeng Xie
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Control Valve ◽  
Internal Flow ◽  
Pulse Frequency ◽  
Computational Fluid Dynamics Cfd ◽  
Steam System ◽  
Normal Work ◽  
Vibration Noise

The medium flow of control valve is a typical complex unsteady flow, the internal flow is very unstable which leads to trim or body with vibration of different amplitude, therefore, control valve has been a failure-prone components in the turbine inlet steam system. This paper take the new valve as the research object, by computational fluid dynamics (CFD) software, the numerical simulation of the internal steam steady state flow field of valve normal work a typical opening in the process of opening is made, and obtain the internal flow field visualization distribution and flow characteristics of control valve. Extract unstable place pressure pulsation of the flow field, get the pulse frequency, and provide the basis for the design, optimization and application of low vibration noise control valve.

Aerodynamic design of 50 per cent reaction steam turbines

1999 ◽  
Vol 213 (1) ◽  
pp. 1-25 ◽  
Author(s):  
S Havakechian ◽  
R Greim
Keyword(s):  
High Efficiency ◽  
Performance Enhancement ◽  
Three Dimensional ◽  
Deep Understanding ◽  
Design Tools ◽  
Steam Turbines ◽  
Aerodynamic Design ◽  
Aerodynamic Properties ◽  
Flow Phenomena

On the basis of their inherent favourable aerodynamic properties coupled with past progress, 50 per cent reaction stages already achieve a high efficiency level. Developments aimed at further performance enhancement entail employment of advanced design features that require a deep understanding of the flow phenomena involved and their interactions. In addition, substantial on-going efforts are needed to improve the quality of the design tools. This paper focuses on the key design issues, including advanced quasi-three-dimensional and three-dimensional design aspects. It further describes developments by the authors' company during the last decade for the design of modern reaction blading and establishment of state-of-the-art design tools.

Optimization of Valve Block Shape Using CFD

2012 ◽  
Vol 190-191 ◽  
pp. 133-138 ◽  
Author(s):  
Qin Yang ◽  
Xian Zhou Wang ◽  
Ming Yue Liu ◽  
Jing Hu ◽  
Zhi Guo Zhang
Keyword(s):  
Fluid Flow ◽  
High Efficiency ◽  
Complex Geometry ◽  
Numerical Study ◽  
Three Dimensional ◽  
Maximum Velocity ◽  
Check Valve ◽  
Low Noise ◽  
Stop Valve ◽  
Valve Block

Stop valves are commonly used as fluid flow control equipments in many engineering applications. A numerical study of a three-dimensional, complex geometry, stop-check valve was performed for model validation and improved understanding of valve flow features. This paper has provided a numerical investigation of the fluid flow inside a stop valve, including the modeling and the simulation of the stop valves. According to the simulation result of original valve structure, two cone valve block shape with different gradient are presented to bring some optimization to the stop-valve. CFD simulations were conducted for different structure of the valve to verify the performance of the valve after redesign the internal flow structure. The simulation results show that the pressure drop vortex strength, maximum velocity and velocity nonuniformity of valve outlet had been reduced obviously. Furthermore, the results of the three-dimensional optimization analysis of valve shape can be used in the design of low noise and high efficiency valve for industry.

Numerical Simulation of the Three-Dimensional Turbulent Flow in Roto-Jet Pump

2013 ◽  
Vol 341-342 ◽  
pp. 375-378 ◽  
Author(s):  
Fang Neng Zhu ◽  
Dong Liu ◽  
Xiao Yong Yang ◽  
Chun Lin Wang
Keyword(s):  
Three Dimensional ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Hydraulic Loss ◽  
Jet Pump ◽  
Suction Surface ◽  
Turbulence Flow ◽  
Flow Phenomena ◽  
Simplec Algorithm ◽  
Diffusion Tube

In order to study the internal flow characteristics of roto-jet pump, the standard turbulence model and SIMPLEC algorithm were used to calculate the three-dimensional turbulence flow field under design condition. The simulation results reveal the internal flow phenomena of roto-jet pump, which shows the pressure near the suction surface and the inlet edge of impeller is minimum, and the cavitations is easy to occur . At the same time, the circumfluence and flow separation phenomenon is not found in the vicinity of the short blade, which is used to shunt the flow. The pressure gradient changed little in the rotor cavity. Is easy to form vortex at manifold import corners, there is no vortex generated on the second corner when the diffusion tube is used. The results obtained in this research provide a theoretical foundation for improving pump performance and reduce the hydraulic loss.

Pulsatile Non-Newtonian Flow Characteristics in a Three-Dimensional Human Carotid Bifurcation Model

1991 ◽  
Vol 113 (4) ◽  
pp. 464-475 ◽  
Author(s):  
K. Perktold ◽  
M. Resch ◽  
H. Florian
Keyword(s):  
Shear Stress ◽  
Carotid Sinus ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Outer Wall ◽  
Maximum Diameter ◽  
Newtonian Flow ◽  
Pulse Cycle ◽  
Flow Phenomena ◽  
Human Carotid

Numerical analysis of flow phenomena and wall shear stresses in the human carotid artery bifurcation has been carried out using a three-dimensional geometrical model. The primary aim of this study is the detailed discussion of non-Newtonian flow velocity and wall shear stress during the pulse cycle. A comparison of non-Newtonian and Newtonian results is also presented. The applied non-Newtonian behavior of blood is based on measured dynamic viscosity. In the foreground of discussion are the flow characteristics in the carotid sinus. The investigation shows complex flow patterns especially in the carotid sinus where flow separation occurs at the outer wall throughout the systolic deceleration phase. The changing sign of the velocity near the outer sinus wall results in oscillating shear stress during the pulse cycle. At the outer wall of the sinus at maximum diameter level the shear stress ranges from −1.92 N/m2 to 1.22 N/m2 with a time-averaged value of 0.04 N/m2. At the inner wall of the sinus at maximum diameter level the shear stress range is from 1.16 N/m2 to 4.18 N/m2 with a mean of 1.97 N/m2. The comparison of non-Newtonian and Newtonian results indicates unchanged flow phenomena and rather minor differences in the basic flow characteristics.

Aeroacoustic Computations of Contra-Rotating Open Rotors Using the Nonlinear Harmonic Method and a Chorochronic Approach

2012 ◽  
Author(s):  
P.-A. Hoffer ◽  
T. Deconinck ◽  
Ch. Hirsch ◽  
B. Ortun ◽  
S. Canard-Caruana ◽  
...  
Keyword(s):  
High Efficiency ◽  
Near Field ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Acoustic Propagation ◽  
Propulsion System ◽  
Scale Model ◽  
Far Field ◽  
Noise Sources ◽  
Harmonic Method

Due to their great potential for fuel saving, Contra-Rotating Open Rotors (CRORs) receive renewed interest by the airframers and the engine manufacturers. The inherent high efficiency of this propulsion system, however, is potentially offset by the level of noise emitted by the open blades. The acoustic impact on passengers and community may represent a major issue to their environmental acceptance. Fast and robust noise prediction tools are clearly required to support the development of quieter propellers and their integration in future civil aeronautical transport. The most common strategy for noise estimation consists in a two-step approach, based on the Lighthill analogy: unsteady near-field aerodynamic flow simulation to evaluate the noise sources, coupled to a far-field acoustic propagation code. Focus is given here on two structured grid flow solvers employed to investigate a scale-model of a 12×10 pusher CROR. The unsteady aerodynamic three-dimensional flow is indeed computed for typical cruise conditions using both the nonlinear harmonic method (NLH) of FINE™/Turbo software and elsA’s chorochronic technique. The evaluation of the far-field noise based on the aerodynamic fields is then carried out with the KIM code, Onera’s acoustic propagation code based on the Ffowcs-Williams and Hawkings (FW-H) formulation. The obtained results enable an analysis of the complex aerodynamic interactions between the two propellers that generate interaction tones in the acoustic signature of the propulsion system. A comparison in terms of numerical settings, computational costs and flow fields is performed between the two CFD methods, which show an excellent match of the predicted global performance of the propulsion system. Some differences in the predicted acoustic signatures are discussed in the paper.

The Design and Numerical Study on Flow Characteristics of High Temperature and High Pressure Steam Trap

2013 ◽  
Vol 655-657 ◽  
pp. 123-126
Author(s):  
Shu Xun Li ◽  
Xing Zhang ◽  
Shi Hao Zhou ◽  
Deng Wei Xu
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Numerical Study ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Low Flow ◽  
Flow Induced Vibration ◽  
Fluid Field ◽  
Steam Trap ◽  
Large Flow

In order to solve the problem of the flow-induced vibration under high temperature and high pressure when opening or closing the steam trap, sleeve was designed and three-dimensional numerical simulation of the internal turbulent fluid field was performed by using Fluent of computational fluid dynamics software. When sleeve is installed ,the results show that flow-adjusting characteristic is equal percentage for different travels , meanwhile, meet the rules that low flow rate is at small opening and large flow is at maximum open degree. It is benefited to suppress the generation of pressure fluctuation and pipe-vibration. This paper will provide a reference for the design of more excellent performance steam trap.

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