An Experimental and Numerical Study of Regulating Performance and Flow Loss in a V-Port Ball Valve

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Junyu Tao ◽  
Zhe Lin ◽  
Chuanjing Ma ◽  
Jiahui Ye ◽  
Zuchao Zhu ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Fluid Transport ◽  
Numerical Study ◽  
Internal Flow ◽  
External Pressure ◽  
Ball Valve ◽  
Flow Coefficient ◽  
Design And Optimization ◽  
Stable Position ◽  
Valve Opening

Abstract Process valves are responsible for regulating and controlling the rate and direction of flow in pipeline systems. The V-port ball valve is one kind of process valve with a regulating performance influenced by V-angle. In this article, a DN50 V-port ball valve is taken as the research object. This work therefore aims to investigate the effect of and relationship between the V-angle on valve performance and internal flow properties via experiments and numerical simulations. Results indicate that an increase in either V-angle or valve opening causes a large-pressure fluctuation near the valve outlet, thus leading to a long pressure-stable distance. Meanwhile, the flow coefficient increases exponentially with valve opening, and the value of the exponent remains at 2.5 for different V-angles. Furthermore, the stable position of internal energy loss along the downstream pipe is well-matched with the stable position of external pressure fluctuation. This inspires a new method for controlling the pressure stability downstream from the valve. These results may facilitate improvements in the design and optimization of the process valve, thus benefiting the development of fluid transport techniques in energy industries.

scholarly journals Numerical Study of the Behaviors of Ventilated Supercavities in a Periodic Gust Flow

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Renfang Huang ◽  
Siyao Shao ◽  
Roger E. A. Arndt ◽  
Xianwu Luo ◽  
Yiwei Wang ◽  
...  
Keyword(s):  
Internal Pressure ◽  
Pressure Fluctuation ◽  
Cavity Length ◽  
Numerical Study ◽  
Maximum Amplitude ◽  
Internal Flow ◽  
External Pressure ◽  
Incoming Flow ◽  
Flow Perturbation ◽  
Number Variation

Abstract We conducted a numerical simulation of ventilated supercavitation from a forward-facing cavitator in unsteady flows generated by a gust generator under different gust angles of attack and gust frequencies. The numerical method is validated through the experimental results under specific steady and unsteady conditions. It is shown that the simulation can capture the degree of cavity shape fluctuation and internal pressure variation in a gust cycle. Specifically, the cavity centerline shows periodic wavelike undulation with a maximum amplitude matching that of the incoming flow perturbation. The cavity internal pressure also fluctuates periodically, causing the corresponding change of difference between internal and external pressure across the closure that leads to the closure mode change in a gust cycle. In addition, the simulation captures the variation of cavity internal flow, particularly the development internal flow boundary layer along the cavitator mounting strut, upon the incoming flow perturbation, correlating with cavity deformation and closure mode variation. With increasing angle of attack, the cavity exhibits augmented wavelike undulation and pressure fluctuation. As the wavelength of the flow perturbation approaches the cavity length with increasing gust frequency, the cavity experiences stronger wavelike undulation and internal pressure fluctuation but reduced cavitation number variation.

scholarly journals Numerical Study of the Microflow Characteristics in a V-ball Valve

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 155
Author(s):  
Zhi-xin Gao ◽  
Yang Yue ◽  
Jia-ming Yang ◽  
Jun-ye Li ◽  
Hui Wu ◽  
...  
Keyword(s):  
Numerical Study ◽  
Flow Characteristics ◽  
Ball Valve ◽  
Loss Coefficient ◽  
Flow Coefficient ◽  
Process Industries ◽  
Opposite Trend ◽  
Small Flow ◽  
Valve Opening ◽  
Flow Cross

V-ball valves are widely applied in many process industries to regulate fluid flow, and they have advantages of good approximately equal percentage flow characteristics and easy maintenance. However, in some applications, the V-ball valve needs to have good performance under both large and extremely small flow coefficients. In this paper, the improvement of the original V-ball valve is made and the flow characteristics between the original and the improved V-ball valve are compared. Two types of small gaps are added to the original V-ball, namely the gap with an approximately rectangular port and the gap with an approximately triangular port. The effects of the structure and the dimension of the gap on flow characteristics are investigated. Results show that within the gap, the flow coefficient increases but the loss coefficient decreases as the valve opening increases, and the flow coefficient has an approximately linear relationship with the flow cross-area of the added gap. Results also show that under the same flow cross-area, the flow coefficient has a higher value if the distance between the gap and the ball center is greater or if the gap is an approximately rectangular port, while the loss coefficient has an opposite trend.

Numerical Study of Pipeline-Riser Slugging in an Open Source Way

2016 ◽  
Author(s):  
Xiangyin Meng ◽  
Longbin Tao
Keyword(s):  
Open Source ◽  
Mesh Generation ◽  
Pressure Fluctuation ◽  
Numerical Study ◽  
Internal Flow ◽  
Post Process ◽  
System Pressure ◽  
Fluid Properties ◽  
Gas Liquid Flow ◽  
First Time

This paper describes an open source numerical investigation into slugging flow in a typical two-dimensional pipeline-riser for the first time. CFD tools Gmsh, OpenFOAM and ParaView are employed for mesh generation, numerical simulation and post process respectively. Original OpenFOAM solver ‘twoPhaseEulerFoam’ is used to simulate the gas-liquid flow in the system consisting of inclined pipeline and vertical riser. By comparing the numerical results of slugging phenomena and pressure fluctuation periods to previous experimental observations, it can be confirmed that it is possible to carry out such simulations in a complete open source way. Based on case studies, pressure fluctuation features in a typical single slugging cycle is also discussed in details. Furthermore, temperature variation of the internal flow due to air compressibility is found to have similar fluctuation period as that of pressure. In the end, the impacts of fluid properties on system pressure variations are discussed too. To future numerical investigations of subsea pipeline-riser induced slugging, present work is a basis for further open source solvers development.

scholarly journals Effect of variable speed motion curve of electric actuator on ball valve performance and internal flow field

2021 ◽  
Vol 13 (6) ◽  
pp. 168781402110280
Author(s):  
Guangfei Ma ◽  
Zhe Lin ◽  
Zuchao Zhu ◽  
Yong Fang
Keyword(s):  
Flow Field ◽  
Internal Flow ◽  
Economic Cost ◽  
Resistance Coefficient ◽  
Transportation Systems ◽  
Ball Valve ◽  
Flow Coefficient ◽  
Variable Speed ◽  
Pipeline Transportation ◽  
Electric Actuator

Ball valve is an important control component in the pipeline transportation system. It is widely used in pipeline transportation systems to control the pressure and flow parameters of the conveying medium. Based on the user-defined UDF technology and the standard k-[Formula: see text] turbulence model using computational fluid dynamics techniques, the transient numerical simulation of the internal flow field of the ball valve under the variable speed law and different opening degrees is carried out, and the flow coefficient characteristics, resistance coefficient characteristics, inlet and outlet pressure drop, and internal flow field distribution of the ball valve are analyzed and studied. The results show that by designing the curve function of the ball valve actuator movement process with different structure forms, different types of ball valve flow coefficient and resistance coefficient curve can be obtained, which makes the ball valve as a flow regulating valve more widely used; Modifying the motion law of ball valve electric actuator has little influence on the distribution of ball valve flow field. As long as the motion law of ball valve actuator is optimized within a reasonable range, the purpose of pipeline flow control can be achieved, the inconvenience of valve replacement can be reduced, and the economic cost can be saved.

scholarly journals Structural Response of a Single-Stage Centrifugal Compressor to Fluid-Induced Excitations at Low-Flow Operating Condition: Experimental and Numerical Study

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4292
Author(s):  
Kirill Kabalyk ◽  
Andrzej Jaeschke ◽  
Grzegorz Liśkiewicz ◽  
Michał Kulak ◽  
Tomasz Szydłowski ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Numerical Study ◽  
Structural Response ◽  
Flow Coefficient ◽  
Low Flow ◽  
Dynamic Strain ◽  
Duct Acoustics ◽  
Numerical Noise ◽  
Partial Load ◽  
Compressor Impeller

The article describes an assessment of possible changes in constant fatigue life of a medium flow-coefficient centrifugal compressor impeller subject to operation at close-to-surge point. Some aspects of duct acoustics are additionally analyzed. The experimental measurements at partial load are presented and are primarily used for validation of unidirectionally coupled fluid-structural numerical model. The model is based on unsteady finite-volume fluid-flow simulations and on finite-element transient structural analysis. The validation is followed by the model implementation to replicate the industry-scale loads with reasonably higher rotational speed and suction pressure. The approach demonstrates satisfactory accuracy in prediction of stage performance and unsteady flow field in vaneless diffuser. The latter is deduced from signal analysis relying on continuous wavelet transformations. On the other hand, it is found that the aerodynamic incidence losses at close-to-surge point are underpredicted. The structural simulation generates considerable amounts of numerical noise, which has to be separated prior to evaluation of fluid-induced dynamic strain. The main source of disturbance is defined as a stationary region of static pressure drop caused by flow contraction at volute tongue and leading to first engine-order excitation in rotating frame of reference. Eventually, it is concluded that the amplitude of excitation is too low to lead to any additional fatigue.

Numerical Study on Flow Characteristics in High Multi-Stage Pressure Reducing Valve

2017 ◽  
Author(s):  
Fu-qiang Chen ◽  
Zhi-xin Gao ◽  
Jin-yuan Qian ◽  
Zhi-jiang Jin
Keyword(s):  
Energy Consumption ◽  
Numerical Study ◽  
Research Work ◽  
Flow Characteristics ◽  
Temperature Fields ◽  
Turbulent Dissipation ◽  
Technological Support ◽  
Multi Stage ◽  
Valve Opening ◽  
Pressure Reducing Valve

In this paper, a new high multi-stage pressure reducing valve (HMSPRV) is proposed. The main advantages include reducing noise and vibration, reducing energy consumption and dealing with complex conditions. As a new high pressure reducing valve, its flow characteristics need to be investigated. For that the valve opening has a great effect on steam flow, pressure reduction and energy consumption, thus different valve openings are taken as the research points to investigate the flow characteristics. The analysis is conducted from four aspects: pressure, velocity, temperature fields and energy consumption. The results show that valve opening has a great effect on flow characteristics. No matter for pressure, velocity or temperature field, the changing gradient mainly reflects at those throttling components for all valve openings. For energy consumption, in the study of turbulent dissipation rate, it can be found that the larger of valve opening, the larger of energy consumption. It can be concluded that the new high multi-stage pressure reducing valve works well under complex conditions. This study can provide technological support for achieving pressure regulation, and benefit the further research work on energy saving and multi-stage design of pressure reducing devices.

A numerical study of the bubble induced pressure fluctuation in gas-fluidized beds

2017 ◽  
Vol 314 ◽  
pp. 387-399 ◽  
Author(s):  
Yuli Zhang ◽  
Rui Xiao ◽  
Mao Ye ◽  
Zhongmin Liu
Keyword(s):  
Pressure Fluctuation ◽  
Fluidized Beds ◽  
Numerical Study ◽  
Gas Fluidized Beds

scholarly journals Performance Improvement of a Liquid Molten Salt Pump: Geometry Optimization and Experimental Verification

Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 423 ◽  
Author(s):  
Kai Wang ◽  
Xin Lu ◽  
Yu Li ◽  
Xianghui He ◽  
Houlin Liu ◽  
...  
Keyword(s):  
Molten Salt ◽  
Performance Improvement ◽  
Pressure Fluctuation ◽  
Geometry Optimization ◽  
Internal Flow ◽  
Experimental Methods ◽  
Sharp Corner ◽  
Hydraulic Efficiency ◽  
Low Velocity ◽  
Pump Performance

In order to enhance the hydraulic efficiency of a liquid molten salt pump, the improvement on the pump was carried out through numerical and experimental methods. The internal flow field obtained by the numerical simulation was analysed. The results show that there are low-velocity area in the scroll region and large curvature of the streamline at the outlet. Geometric modification was made by trimming the back-blades of the impeller and filleting the sharp corner of the outlet pipe. The modified pump performance was verified by the experiments. The hydraulic efficiency, the pressure fluctuation, vibration characteristics between the original and modified pump were compared. The results showed that the hydraulic efficiency of the modified pump increased 7.4%. In addition, the pressure fluctuation and vibration intensity were also reduced compared with the original pump. This result shows that the geometric modification improves not only the hydraulic performance but also the structural properties.

scholarly journals Reduction of shrinkage porosities in aluminum alloy castings by external pressure fluctuation under gravity field

China Foundry ◽  
2018 ◽  
Vol 15 (5) ◽  
pp. 372-377 ◽  
Author(s):  
Shi-ping Wu ◽  
Ru-jia Wang ◽  
Ye Wang ◽  
Wei Chen ◽  
Ze-sheng Ji
Keyword(s):  
Aluminum Alloy ◽  
Gravity Field ◽  
Pressure Fluctuation ◽  
External Pressure ◽  
Alloy Castings
Sign in / Sign up

Export Citation Format

Share Document