Numerical study on the flow characteristics in swirl meter

The swirl meter (vortex precession flow meter) popularly used in natural gas industry is a kind of velocity flow meter with high turndown ratio and well performance in low flow measurement and other known advantages. In order to further understand the flow pattern of swirl meter to further improve its performance, computational fluid dynamics simulations are used to simulate the flow and predict the coefficient for swirl meter at different flow rates. Using renormalization group k–ε turbulent model and SIMPLEC algorithm, numerical simulations have been performed through commercial codes Fluent, and meter coefficients are also obtained experimentally to validate the numerical results. The simulated velocity and pressure in swirl meter are analyzed in detail, which are time-averaged distributions during a time period based on the transient numerical simulation. It is found that centerline pressure is lowest at the outlet of the swirler and rises gradually along the axial direction. While near-wall pressure presents an opposite variation tendency, it is significantly low at the end of throat due to strong influence of vortex precession. Centerline velocity increases as the flow approaches throat and reaches its maximum at center region of throat, and then it decreases and keeps relatively stable at downstream of divergent section. Both time-averaged pressure and axial velocity distributions are axisymmetric, and pressure variation is small on the cross section at the end of throat, although vortex precession is strong.

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Numerical Study on the Influence of Inlet Guide Vanes on the Internal Flow Characteristics of Centrifugal Pump

Processes ◽

10.3390/pr8010122 ◽

2020 ◽

Vol 8 (1) ◽

pp. 122 ◽

Cited By ~ 3

Author(s):

Peifeng Lin ◽

Yongzheng Li ◽

Wenbin Xu ◽

Hui Chen ◽

Zuchao Zhu

Keyword(s):

Centrifugal Pump ◽

Numerical Study ◽

Flow Characteristics ◽

Internal Flow ◽

Low Flow ◽

Hydraulic Loss ◽

Inlet Pipe ◽

Monitoring Point ◽

Guide Vanes ◽

Sst Turbulence Model

In order to make the centrifugal pump run efficiently and stably under various working conditions, the influences of the incoming vortex flow in the inlet pipe on the main flow in the impeller is studied numerically, based on the k − ω SST turbulence model. Some guide vanes with different offset angle were added to change the statistical characteristic of the internal flow in the inlet pipe of the centrifugal pump. Both contour distributions of internal flow and statistical results of external performance are obtained and analyzed. The results show that the existence of vanes can divide the large vortex because of the reversed flow from the rotating impeller at low flow rate conditions into small vortices, which are easier to dissipate, make the velocity and pressure distribution more uniform, improve the stability of the flow in the impeller, reduce the hydraulic loss, and improve the hydraulic performance of the pump. The pump with vanes of offset angle 25° has a small pressure pulsation amplitude at each monitoring point. Comparing with the performance of the original pump, the head increased by around 2% and efficiency increased by around 2.5% of the pump with vanes of offset angle 25°.

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Numerical Study of Turbulent Flow and Convective Heat Transfer Characteristics in Helical Rectangular Ducts

Journal of Heat Transfer ◽

10.1115/1.4028583 ◽

2014 ◽

Vol 136 (12) ◽

Cited By ~ 3

Author(s):

Yunfei Xing ◽

Fengquan Zhong ◽

Xinyu Zhang

Keyword(s):

Heat Transfer ◽

Convective Heat Transfer ◽

Convective Heat ◽

Numerical Study ◽

Rectangular Cross Section ◽

Three Dimensional ◽

Flow Characteristics ◽

Axial Direction ◽

Outer Wall ◽

Centrifugal Effect

Three-dimensional turbulent forced convective heat transfer and its flow characteristics in helical rectangular ducts are simulated using SST k–ω turbulence model. The velocity field and temperature field at different axial locations along the axial direction are analyzed for different inlet Reynolds numbers, different curvatures, and torsions. The causes of heat transfer differences between the inner and outer wall of the helical rectangular ducts are discussed as well as the differences between helical and straight duct. A secondary flow is generated due to the centrifugal effect between the inner and outer walls. For the present study, the flow and thermal field become periodic after the first turn. It is found that Reynolds number can enhance the overall heat transfer. Instead, torsion and curvature change the overall heat transfer slightly. But the aspect ratio of the rectangular cross section can significantly affect heat transfer coefficient.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.655-657.123 ◽

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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Finding Fault with the Nexus Pipeline? Agency Capture and the Public Good

Case Studies in the Environment ◽

10.1525/cse.2017.sc.453098 ◽

2017 ◽

Vol 1 (1) ◽

pp. 1-8

Author(s):

Andrew R. Kear

Keyword(s):

Natural Gas ◽

Environmental Impact ◽

Public Good ◽

Health And Safety ◽

Environmental Impact Statement ◽

Gas Industry ◽

The Public ◽

Fracturing Process ◽

Natural Gas Industry ◽

Regulatory Commission

Natural gas is an increasingly vital U.S. energy source that is presently being tapped and transported across state and international boundaries. Controversy engulfs natural gas, from the hydraulic fracturing process used to liberate it from massive, gas-laden Appalachian shale deposits, to the permitting and construction of new interstate pipelines bringing it to markets. This case explores the controversy flowing from the proposed 256-mile-long interstate Nexus pipeline transecting northern Ohio, southeastern Michigan and terminating at the Dawn Hub in Ontario, Canada. As the lead agency regulating and permitting interstate pipelines, the Federal Energy Regulatory Commission is also tasked with mitigating environmental risks through the 1969 National Environmental Policy Act's Environmental Impact Statement process. Pipeline opponents assert that a captured federal agency ignores public and scientific input, inadequately addresses public health and safety risks, preempts local control, and wields eminent domain powers at the expense of landowners, cities, and everyone in the pipeline path. Proponents counter that pipelines are the safest means of transporting domestically abundant, cleaner burning, affordable gas to markets that will boost local and regional economies and serve the public good. Debates over what constitutes the public good are only one set in a long list of contentious issues including pipeline safety, proposed routes, property rights, public voice, and questions over the scientific and democratic validity of the Environmental Impact Statement process. The Nexus pipeline provides a sobering example that simple energy policy solutions and compromise are elusive—effectively fueling greater conflict as the natural gas industry booms.

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