Numerical Study of the Effects of Upstream Flow Condition Upon Orifice Flow Meter Performance

1993 ◽  
Vol 115 (4) ◽  
pp. 213-218 ◽  
Author(s):  
G. L. Morrison ◽  
D. L. Panak ◽  
R. E. DeOtte
Keyword(s):  
Velocity Profile ◽  
Flow Condition ◽  
Numerical Study ◽  
Orifice Plate ◽  
Mean Velocity ◽  
Orifice Flow ◽  
Coefficient Of Discharge ◽  
Orifice Flow Meter ◽  
Recent Experimental Work ◽  
Upstream Flow

Recent experimental work has shown that when the mean velocity profile upstream of an orifice plate has a deficit on the centerline and higher velocities at the outer edges of the pipe, the pressure drop across the orifice is greater than if the flow upstream is “fully developed.” It is proposed that this increase in ΔP is directly correlated with the radial distribution of momentum upstream of the orifice plate. In an effort to investigate how the upstream flow condition affects the pressure distribution along the pipe wall and to determine if the hypothesis is correct, Creare.X Inc.’s FLUENT numerical analysis program was used to simulate the effects. Two β ratios (0.50 and 0.75) have been considered with various mean velocity inlet profiles. Inlet profiles include the 1/6th, 1/7th, 1/8th, 1/9th and 1/10th power law, uniform flow, and two linear distributions. The results indicate that there is a correlation between the second and third-order moments of momentum and the value of the discharge coefficient. This empirical correlation, after being fully verified by experimental data, can be used to estimate the change in the coefficient of discharge given the inlet velocity profile.

Three-Dimensional Flow Analysis for Estimation of Measuring Error of Orifice Flowmeter Due to Upstream Flow Distortion

2002 ◽  
Author(s):  
Hong-Min Kim ◽  
Kwang-Yong Kim ◽  
Jae-Young Her ◽  
Young-Chul Ha
Keyword(s):  
Flow Analysis ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Measuring Error ◽  
Flow Distortion ◽  
Three Dimensional Flow ◽  
Pipe System ◽  
Orifice Flow ◽  
Orifice Flow Meter ◽  
Upstream Flow

Three-dimensional pipe flows with elbows and tees are calculated to estimate the effect of upstream flow distortion on measuring accuracy of orifice flow meter. Axisymmetric flows through orifice are calculated first to evaluate the performances of various numerical schemes and turbulence models. In three-dimensional calculations of the flow in pipe system, it is evaluated how the pressure difference across the orifice is dependent on the length of upstream straight pipe in a branch. From the results, it is found that, regardless of flow rate, the effect of the length can be neglected for the lengths larger than thirty diameters although there still remain significant swirl at the orifice.

Experimental and Numerical Study of Hydrodynamic Cavitation of Orifice Plates with Multiple Triangular Holes

2012 ◽  
Vol 256-259 ◽  
pp. 2519-2522 ◽  
Author(s):  
Zhi Yong Dong ◽  
Qi Qi Chen ◽  
Yong Gang Yang ◽  
Bin Shi
Keyword(s):  
Velocity Profile ◽  
High Speed ◽  
Numerical Study ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Orifice Plate ◽  
Hydrodynamic Cavitation ◽  
High Speed Photography ◽  
Hydraulic Characteristics ◽  
Image Velocimetry

Hydraulic characteristics of orifice plates with multiple triangular holes in hydrodynamic cavitation reactor were experimentally investigated by use of three dimensional particle image velocimetry (PIV), high speed photography, electronic multi-pressure scanivalve and pressure data acquisition system, and numerically simulated by CFD software Flow 3D in this paper. Effects of number, arrangement and ratio of holes on hydraulic characteristics of the orifice plates were considered. Effects of arrangement and ratio of holes and flow velocity ahead of plate on cavitation number and velocity profile were compared. Distribution of turbulent kinetic energy and similarity of velocity profile were analyzed. And characteristics of cavitating flow downstream of the orifice plate were photographically observed by high speed camera. Also, a comparison with flow characteristics of orifice plate with hybrid holes (circle, square and triangle) was made.

Effect of Kinematic Operating Conditions on Ridge Deformation—Numerical Study With Experimental Comparison

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Ildikó Ficza ◽  
Petr Šperka ◽  
Ivan Křupka ◽  
Martin Hartl
Keyword(s):  
Numerical Study ◽  
Operating Conditions ◽  
Experimental Comparison ◽  
Roughness Effects ◽  
Mean Velocity ◽  
Recent Experimental Work ◽  
Theoretical Analyses ◽  
Highly Loaded ◽  
Contact Part ◽  
Ehl Contact

The behavior of roughness features under rolling–sliding inside highly loaded elastohydrodynamically lubricated (EHL) contacts is studied in detail for many years now. In particular, the roughness deformation was subject to different theoretical analyses as well as experiments. A recent experimental work developed by Šperka et al. (2016, “Experimental Study of Roughness Effects in a Rolling–Sliding EHL Contact—Part I: Roughness Deformation,” Tribol. Trans., 59(2), pp. 267–276) studied the effect of kinematic operating conditions (mean velocity and slide to roll ratio) on the deformed profile of a ridge. The current paper presents results of full numerical simulations and their direct comparison to experiments in order to study the dependency of roughness deformation on the operating conditions. The assumption of non-Newtonian lubricant behavior seems to have a significant influence on the results as well. Results indicate that, in agreement with experiments, the variation of mean velocity causes changes in the deformed profiles of roughness while, on the other hand, the magnitude of slide to roll ratio (for sliding larger than ±50%) does not have influence on the size of the deformation.

scholarly journals Pengujian Orifice Flow Meter dengan Kapasitas Aliran Rendah

MECHANICAL ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Ainul Ghurri ◽  
S.P.G. Gunawan Tisna ◽  
Syamsudin Syamsudin
Keyword(s):  
Low Cost ◽  
Metal Plate ◽  
Diameter Ratio ◽  
Orifice Plate ◽  
Low Flow ◽  
Inlet Section ◽  
Flow Meter ◽  
Flow Capacity ◽  
Orifice Flow ◽  
Orifice Flow Meter

Orifice flow meter is used in many laboratory and industrial application due because of its simple design and low cost. The present research investigated an orifice flow meter operated in relatively low flow rate. Orifice plate is a metal plate, 10 mm width provided with bevel at inlet section. The diameter ratios (β) are 0.3, 0.4, 0.5, 0.6, 0.7, and 0.8, respectively. The experiment used water with flowrate range having Reynolds number between 6827,55 and 8004,72. The fluid is flown through the orifice plate. Pressure taps are used to measure pressure at upstream and downstream of the orifice plate. The actual capacity is directly measured at an outlet reservoir; while the theoretical capacity is calculated using modified Bernoulli equation with diameter ratio (β) within the equation. The results showed that the irrecoverable pressure drop decreased with the increase of flow capacity and the diameter ratio. The discharge coefficient of the orifice flowmeter ranged between 0.3 and 1.3.

Investigation of the influence of the flow structure on the accuracy of flow measurement before a hydrometric structure in an open channel

2020 ◽  
pp. 41-44
Author(s):  
Anatoly Kusher
Keyword(s):  
Velocity Profile ◽  
Flow Velocity ◽  
Water Flow ◽  
Flow Measurement ◽  
Water Discharge ◽  
Critical Depth ◽  
Flow Measurements ◽  
Study Results ◽  
Flow Velocity Profile ◽  
Upstream Flow

The reliability of water flow measurement in irrigational canals depends on the measurement method and design features of the flow-measuring structure and the upstream flow velocity profile. The flow velocity profile is a function of the channel geometry and wall roughness. The article presents the study results of the influence of the upstream flow velocity profile on the discharge measurement accuracy. For this, the physical and numerical modeling of two structures was carried out: a critical depth flume and a hydrometric overfall in a rectangular channel. According to the data of numerical simulation of the critical depth flume with a uniform and parabolic (1/7) velocity profile in the upstream channel, the values of water discharge differ very little from the experimental values in the laboratory model with a similar geometry (δ < 2 %). In contrast to the critical depth flume, a change in the velocity profile only due to an increase in the height of the bottom roughness by 3 mm causes a decrease of the overfall discharge coefficient by 4…5 %. According to the results of the numerical and physical modeling, it was found that an increase of backwater by hydrometric structure reduces the influence of the upstream flow velocity profile and increases the reliability of water flow measurements.

Оdrеđivаnjе brzinе struјаnjа vаzduhа u prаvоugаоnоm zаtvоrеnоm cevovodu korišćenjem metoda polja brzina

2021 ◽  
Vol 23 (2) ◽  
pp. 57-63
Author(s):  
Marija Lazarevikj ◽  
◽  
Valentino Stojkovski ◽  
Viktor Iliev
Keyword(s):  
Velocity Profile ◽  
Flow Rate ◽  
Air Flow ◽  
Displacement Transducer ◽  
Linear Displacement ◽  
Local Velocity ◽  
Air Flow Rate ◽  
Mean Velocity ◽  
Measured Velocity ◽  
Integration Techniques

In the technical practice, it is often necessary to measure or control the fluid flow rate in pipelines and channels. The velocity-area method requires a number of meters located at specified points in a suitable cross-section of closed conduits. Simultaneous measurements of local mean velocity with the meters are integrated over the gauging section to provide the discharge. In this paper, three approaches of this method are applied on a rectangular closed conduit to determine the air flow rate with integration techniques used to compute the discharge assume velocity distributions that closely approximate known laws, especially in the neighborhood of solid boundaries. For this purpose, meters for velocity were 7 Pitot tubes placed vertically in predefined measurement points covering the conduit height, and moved horizontally along the conduit width. The position of the Pitot tubes along the conduit width was monitored and controlled by a linear displacement transducer. Pressure is measured using digital sensors. The first technique for determination of air flow rate is on basis of fixed (stopping) measuring points across the conduit width as averaged values of local velocity, the second one is semi continual measurement of velocity profile by applying interpolation between the average local velocity on fixed (stopping) points and measured velocity in the movement between two positions, and the third is by continuously moving the Pitot tubes without stopping. The results of the three techniques are calculated and presented using different types of software. Considering the last technique, comparison of results is made applying different movement speeds of the Pitot tubes in order to examine their influence on the velocity profile.

scholarly journals Effect of the Flame Dome Depth and Improvement of the Pressure Loss in the Dump Diffuser

1998 ◽  
Author(s):  
Shinji Honami ◽  
Wataru Tsuboi ◽  
Takaaki Shizawa
Keyword(s):  
Velocity Profile ◽  
Reynolds Stress ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Flow Behavior ◽  
Sudden Expansion ◽  
Mean Velocity ◽  
The Mean ◽  
Stress Profiles

This paper presents the effect of flame dome depth on the total pressure performance and flow behavior in a sudden expansion region of the combustor diffuser without flow entering the dome head. The mean velocity and turbulent Reynolds stress profiles in the sudden expansion region were measured by a Laser Doppler Velocitmetry (LDV) system. The experiments show that total pressure loss is increased, when flame dome depth is increased. Installation of an inclined combuster wall in the sudden expansion region is suggested from the viewpoint of a control of the reattaching flow. The inclined combustor wall is found to be effective in improvement of the diffuser performance. Better characteristics of the flow rate distribution into the branched channels are obtained in the inclined wall configuration, even if the distorted velocity profile is provided at the diffuser inlet.

Numerical Study on the Effect of Bend Angle on Turbulent Flow through Oscillating Bend

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
Elham Ameri ◽  
M Nasr Esfahany
Keyword(s):  
Numerical Study ◽  
Bend Angle ◽  
Curvature Radius ◽  
Primary Flow ◽  
Mean Velocity ◽  
Contour Map ◽  
Curved Pipes ◽  
Flow Through ◽  
The Mean ◽  
Turbulent Air Flow

The effect of the bend angle on the unsteady developing turbulent air flow through oscillating circular-sectioned curved pipes with the various angles of 180°, 135° and 90° was investigated numerically. The bends had a diameter of 106 mm and a curvature radius ratio of 6.0 with long, straight upstream and downstream sections. Results of the mean velocity and static pressure were obtained at a Reynolds number of 31200 and at various longitudinal stations. The velocity of the primary flow was illustrated in the form of contour map and vector diagram. From the inlet plane of the three oscillating bends to the angle of 45°, the velocity fields in 180°, 90° and 135° bends are similar. The high velocity regions, however, occur near the upper and lower parts in 90° and 180° bends, respectively.

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