Flow Characteristics and Stress Analysis of a Parallel Gate Valve

Gate valves have been widely used in the piping system and have attracted a lot of attention from researchers. In this paper, a wedge-type double disk parallel gate valve is chosen to be analyzed. The Reynolds number varying from 200 to 500,000, and the valve opening degree varying from 20% to 100%, and the groove depth varying from 2.3 mm to 9 mm are chosen to investigate their effects on the flow and loss coefficients of the gate valve. The results show that the loss coefficient decreases and the flow coefficient increases with the increase of the Reynolds number and the valve opening degree, while with the increase of the groove depth, the loss coefficient barely changes, but the flow coefficient increases if the Reynolds number is larger than 10,000. In addition, the effects of the gaps between the disk and the limit stop on the stress distribution of the bolt are also investigated, and the results show that if the gaps are negative, high stress will act on the bolt at the contact position between the bolt and the limit stop.

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Experimental Study on Pressure Distribution and Flow Coefficient of Globe Valve

Processes ◽

10.3390/pr8070875 ◽

2020 ◽

Vol 8 (7) ◽

pp. 875 ◽

Cited By ~ 3

Author(s):

Quang Khai Nguyen ◽

Kwang Hyo Jung ◽

Gang Nam Lee ◽

Sung Bu Suh ◽

Peter To

Keyword(s):

Reynolds Number ◽

Pressure Distribution ◽

Full Range ◽

Flow Characteristics ◽

National Standards ◽

Flow Coefficient ◽

Test Loop ◽

Close Range ◽

Valve Opening ◽

Globe Valve

In this study, the pressure distribution and flow coefficient of a globe valve are investigated with a series of experiments conducted in a flow test loop. The experiments are performed on a three-inch model test valve from an eight-inch ANSI (American National Standards Institute) B16.11—Class 2500# prototype globe valve with various pump speeds and full range of valve openings. Both inherent and installed flow characteristics are measured, and the results show that the flow coefficient depends not only on the valve geometry and valve opening but also on the Reynolds number. When the Reynolds number exceeds a certain value, the flow coefficients are stable. In addition, the pressures at different positions in the upstream and the downstream of the valve are measured and compared with recommendation per ANSI/ISA-75.01 standard. The results show that, in single-phase flow, the discrepancies in pressure between different measurement locations within close range of 10 nominal diameter from the valve are inconsiderable.

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

Micromachines ◽

10.3390/mi12020155 ◽

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.

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Study on the eccentric jet-flow characteristics induced by the opening regulation with a gate valve

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406221994889 ◽

2021 ◽

pp. 095440622199488

Author(s):

De-sheng Chen ◽

Yong-xiang Wang ◽

Qi Liu ◽

Zhe Lin ◽

Zu-chao Zhu ◽

...

Keyword(s):

Cross Sections ◽

Axial Velocity ◽

Gate Valve ◽

Flow Characteristics ◽

Flow Simulation ◽

Jet Flow ◽

Valve Opening ◽

Induced Flow ◽

And Control ◽

Small Valve

Valve-induced flow characteristics were often concerned in many fluid transportation and control industries. In this paper, the eccentric jet-flow characteristics induced by a gate valve have been studied by considering the influence of valve opening regulation. The experimental setup of monitoring the downstream pressures along the pipeline was developed, and corresponding numerical simulation was employed. The downstream-monitoring pressure distribution caused by valve opening regulation was investigated to verify the flow simulation. The generation mechanism of eccentric jet-flow was revealed as a strong pressure gradient caused by the throttling effect at the valve throat. It was found that the eccentric jet-flow evolved in the pipeline was accompanied by shearing vortices, extremely under a small valve opening. The pressure and axial velocity distributions at various downstream cross-sections of the eccentric jet-flow evolving in the pipeline were analyzed. The axial velocities on four monitoring lines in downstream cross-sections were extracted, and the radial location of the maximum axial velocity was derived to assess the eccentric characteristics of jet-flow. A dimensionless parameter of velocity eccentric ratio was introduced to quantify the eccentric intensity of the evolving jet-flow in the downstream pipeline, and its correlation with the pipeline length could be adequately expressed by a natural decreasing exponential curve via fitting analysis. By virtue of that correlation, the critical pipeline length was proposed that can be used as the judgment to the terminal of the eccentric jet-flow evolving in the downstream pipeline. This study was helpful to characterize the valve-induced flow characteristics in scientific research and provide useful insight into fluid and mechanical engineering.

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Flow Characteristics of the Nozzle Blade Cascade in the Mode of the Joint Operation with the Radial Diffuser

NTU KhPI Bulletin Power and heat engineering processes and equipment ◽

10.20998/2078-774x.2021.03.01 ◽

2021 ◽

pp. 5-11

Author(s):

Alexander Lapuzin ◽

Valery Subotovich ◽

Yuriy Yudin ◽

Svetlana Naumenko ◽

Ivan Malymon

Keyword(s):

Reynolds Number ◽

Flow Rate ◽

Rate Coefficient ◽

Measurement Data ◽

Flow Characteristics ◽

Flow Coefficient ◽

Blade Cascade ◽

Flow Rate Coefficient ◽

Wide Range ◽

Nozzle Blade

The obtained research data are given for the nozzle cascade used by a small-size gas turbine of an average fanning in combination with the radial diffuser. Aerodynamic characteristics of the nozzle blade cascade were determined in a wide range of a change in the Reynolds number varying from 4∙105 to 106 and the reduced velocity varying in the range of 0.4 to 1.13. The flow rate coefficient of the nozzle cascade was derived for all modes using the integral methods and the drainages behind the cascade. The kinetic energy loss coefficient and the flow angles were calculated using the measurement data of flow parameters in three control modes that were obtained due to the use of orientable pneumometric probes. When the expansion degree of the convergent –divergent annular duct behind the cascade is equal to 1.43 the flow in the narrow section of this duct is “enlocked” in the mode when the reduced velocity behind the cascade is equal to 1.127. At such velocity the Reynolds number 106 is self-similar for the flow rate coefficient. At lower values of Reynolds number, the decrease of it is accompanied by an intensive decrease in the flow rate coefficient for all the values of the reduced velocity. For the Reynolds number lower than 7∙105 an increase in the velocity results in a decreased flow rate coefficient. When this number exceeds 8∙105 an increase in the velocity results in an increase of the flow coefficient up to the moment when the flow is “enlocked” in the nozzle cascade.

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Laminar Pressure Loss Coefficient in Close Coupled Fittings

Fluids Engineering ◽

10.1115/imece2006-15999 ◽

2006 ◽

Author(s):

Murthy Lakshmiraju ◽

Jie Cui

Keyword(s):

Reynolds Number ◽

Pressure Loss ◽

Total Pressure ◽

Laminar Flows ◽

Loss Coefficient ◽

Piping System ◽

Duct System ◽

Pressure Loss Coefficient ◽

Intermediate Distance ◽

Loss Coefficients

Close-coupled fittings are widely used in piping system to change the direction of the fluid and to connect pipes. These fittings cause losses and these losses play a significant role in the total pressure loss in a duct system. Numerical simulations were performed using Fluent on laminar flows in a circular pipe to obtain pressure loss coefficients associated with different fittings of two elbows and three elbows. Each configuration was studied with different intermediate distances between fittings of 0, 1, 3, 5, and 10 pipe diameters. It was observed that for a Reynolds number of 100 and for an intermediate distance less than 5 pipe diameters, the pressure loss coefficient for the coupled fittings was less than that of the uncoupled fittings. While the fittings become uncoupled when the intermediate distance was greater than 5 pipe diameters. Variation of velocity along the axis of the pipe was analyzed to understand the mechanism of the pressure loss for various fitting configurations with different intermediate distances.

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Comparative analysis of regulating characteristics between air-ring flow regulating valve and center butterfly valve

PLoS ONE ◽

10.1371/journal.pone.0251943 ◽

2021 ◽

Vol 16 (5) ◽

pp. e0251943

Author(s):

Shixian Wu ◽

Heqing Liu ◽

Yongping Chen

Keyword(s):

Flow Resistance ◽

Flow Characteristics ◽

Maximum Velocity ◽

Experimental System ◽

Resistance Coefficient ◽

Flow Coefficient ◽

Pipeline System ◽

Butterfly Valve ◽

Abrasive Erosion ◽

Valve Opening

In this study, a novel air-ring flow regulating valve was proposed to reduce the flow resistance caused by valve structural pressure drop in fluid transportation pipeline system. The regulating characteristics at different valve openings were analyzed by numerical method and the results were compared with the center butterfly valve which is most widely applied in fluid transportation pipeline system. Besides, an experimental system was designed to validate the numerical model in the present study. The results indicated that the simulation results agree well with experimental data. The resistance coefficient of the air-ring flow regulating valve is smaller than that of the center butterfly valve when the valve opening is greater than 67%, and the resistance coefficient is reduced by up to 100% as the valve is fully opened. Both valves maintain approximately equal percentage flow characteristics, the deviation in relative flow coefficient is small. In addition, the wall shear stress of the air-ring flow regulating valve is much smaller than that of the center butterfly valve at the same valve opening, and the maximum velocity in the pipeline system is always smaller than that of the center butterfly valve, which significantly reduces valve surface abrasive erosion and thus prolongs its service life.

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Effects of Compressibility on Flow Characteristics and Dynamics of Swing Check Valves—Part II

Journal of Pressure Vessel Technology ◽

10.1115/1.2842284 ◽

1997 ◽

Vol 119 (2) ◽

pp. 199-206 ◽

Cited By ~ 6

Author(s):

K. K. Botros ◽

O. Roorda

Keyword(s):

Compressible Flows ◽

Incompressible Flows ◽

Reverse Flow ◽

Flow Characteristics ◽

Piping System ◽

Numerical Investigations ◽

Transient Flows ◽

Flow Deceleration ◽

Valve Opening ◽

Good Agreement

Part II of this paper is concerned with two aspects of the dynamic behavior of swing-type check valves, namely, slamming of the disk and the maximum attainable reverse flow as the valve closes due to flow deceleration. Both aspects are well understood in incompressible flows, but not as well in applications involving fluids of relatively higher compressibility. A systematic approach in studying these phenomena in compressible flows is followed, and where possible, comparison with incompressible flow applications (e.g., water) is made. Both experimental and numerical investigations were carried out and results presented. Measurements were taken on an NPS 4 test rig in air and in water to provide fundamental comparisons of the two applications. The numerical investigation was based on the solution of the full equation of motion of the swing disk, including damping and counterbalance weights, and utilizing the valve opening-flow characteristics model developed in Part I in a quasi-steady manner. Transient flows in the connecting piping system upstream and downstream of the valve were analyzed based on the standard method of characteristics to solve the full one-dimensional conservation equations. Good agreement was obtained between numerical and experimental results which allowed further numerical investigations of the effects of various parameters in applications involving fluids of relatively higher compressibility.

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Study on flow and heat transfer characteristics for propane in twisted oval and the two-start twisted helically wound tube

Advances in Mechanical Engineering ◽

10.1177/16878140211067025 ◽

2021 ◽

Vol 13 (12) ◽

pp. 168781402110670

Author(s):

Jiawen Yu ◽

Jie Chen ◽

Xiaoguang Mi ◽

Yiqiang Jiang ◽

Xiaozhou Fan ◽

...

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Flow Characteristics ◽

Groove Depth ◽

Heat Transfer Characteristics ◽

Empirical Formulas ◽

Twisted Tube ◽

Transfer Characteristics ◽

Flow And Heat Transfer ◽

Twist Pitch

In this paper, the numerical simulation was used to study the flow and heat transfer characteristics for twisted oval and two-start twisted helically wound tubes with Reynolds numbers 4000–16,000. The significant factors that affect the flow and heat transfer characteristics were analyzed. The range of twist pitch p is 0.02–0.10 m, and ellipse ratio r is 1.2–2 for twisted oval tube, the groove depth e is 0.4–2 mm for two-start twisted tube. The result showed that the relative friction coefficient and Nusselt number increased with the increase of ellipse ratio r and decreased with the increase of twist pitch p for twisted oval helically wound tube. With the growth of Reynolds number, the effects of twist pitch p and ellipse ratio r on the flow characteristics decreased. In addition, the average level of the thermal enhancement factor TEF of the two-start twisted was higher than that of the twisted oval helically wound tube. The maximum enhancements factor TEF of 1.1312 is obtained with groove depth of 2.0, twisted pitch of 0.02, and Reynolds number of 4000 for the two-start twisted tube. Finally, new empirical formulas for flow and heat transfer in helically wound tubes were proposed for two kinds of enhanced tubes.

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Analysis of Flow Characteristics and Effects of Turbulence Models for the Butterfly Valve

Applied Sciences ◽

10.3390/app11146319 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6319

Author(s):

Sung-Woong Choi ◽

Hyoung-Seock Seo ◽

Han-Sang Kim

Keyword(s):

Turbulence Model ◽

Dissipation Rate ◽

Flow Characteristics ◽

Turbulence Models ◽

Flow Properties ◽

Nominal Diameter ◽

Large Pressure ◽

Sst Model ◽

Turbulence Effect ◽

Valve Opening

In the present study, the flow characteristics of butterfly valves with different sizes DN 80 (nominal diameter: 76.2 mm), DN 262 (nominal diameter: 254 mm), DN 400 (nominal diameter: 406 mm) were numerically investigated under different valve opening percentages. Representative two-equation turbulence models of two-equation k-epsilon model of Launder and Sharma, two-equation k-omega model of Wilcox, and two-equation k-omega SST model of Menter were selected. Flow characteristics of butterfly valves were examined to determine turbulence model effects. It was determined that increasing turbulence effect could cause many discrepancies between turbulence models, especially in areas with large pressure drop and velocity increase. In addition, sensitivity analysis of flow properties was conducted to determine the effect of constants used in each turbulence model. It was observed that the most sensitive flow properties were turbulence dissipation rate (Epsilon) for the k-epsilon turbulence model and turbulence specific dissipation rate (Omega) for the k-omega turbulence model.

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Experimental Investigation of Effect of Tip Coolant Ejection on Internal Flow Characteristics Within a Realistic Blade Coolant Channel

Volume 3A: Heat Transfer ◽

10.1115/gt2013-94136 ◽

2013 ◽

Author(s):

Jian Pu ◽

Zhaoqing Ke ◽

Jianhua Wang ◽

Lei Wang ◽

Hongde You

Keyword(s):

Experimental Investigation ◽

Reynolds Number ◽

Pressure Drop ◽

Turbine Blade ◽

Flow Rate ◽

Flow Characteristics ◽

Reynolds Numbers ◽

Flow Ratio ◽

Lp Turbine ◽

Mass Flow Ratio

This paper presents an experimental investigation on the characteristics of the fluid flow within an entire coolant channel of a low pressure (LP) turbine blade. The serpentine channel, which keeps realistic blade geometry, consists of three passes connected by a 180° sharp bend and a semi-round bend, 2 tip exits and 25 trailing edge exits. The mean velocity fields within several typical cross sections were captured using a particle image velocimetry (PIV) system. Pressure and flow rate at each exit were determined through the measurements of local static pressure and volume flow rate. To optimize the design of LP turbine blade coolant channels, the effect of tip ejection ratio (ER) from 180° sharp bend on the flow characteristics in the coolant channel were experimentally investigated at a series of inlet Reynolds numbers from 25,000 to 50,000. A complex flow pattern, which is different from the previous investigations conducted by a simplified square or rectangular two-pass U-channel, is exhibited from the PIV results. This experimental investigation indicated that: a) in the main flow direction, the regions of separation bubble and flow impingement increase in size with a decrease of the ER; b) the shape, intensity and position of the secondary vortices are changed by the ER; c) the mass flow ratio of each exit to inlet is not sensitive to the inlet Reynolds number; d) the increase of the ER reduces the mass flow ratio through each trailing edge exit to the extent of about 23–28% of the ER = 0 reference under the condition that the tip exit located at 180° bend is full open; e) the pressure drop through the entire coolant channel decreases with an increase in the ER and inlet Reynolds number, and a reduction about 35–40% of the non-dimensional pressure drop is observed at different inlet Reynolds numbers, under the condition that the tip exit located at 180° bend is full open.

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