Electromagnetic Flowmeter Primary Elements

1959 ◽  
Vol 81 (4) ◽  
pp. 660-666 ◽  
Author(s):  
V. P. Head
Keyword(s):  
Reynolds Number ◽  
Rate Equation ◽  
Electromagnetic Flowmeter ◽  
Flow Coefficient ◽  
Electrically Conducting ◽  
Volume Rate ◽  
Set Up

An obstructionless flowmeter for electrically conducting liquids is described. Tentative design and inspection criteria which have been found to provide accuracies of ±1/2 per cent, or as little as ±0.005 fps pipeline velocity, are set up. A practical threshold conductivity of meterable liquids is set at 20 micromhos per cm, though there is every reason to believe this will be drastically cut with further progress. Above this threshold, the flow coefficient in the volume-rate equation is shown by tests to be independent of the conductivity, of the Reynolds number, and of installation conditions.

Reynolds Number and Roughness Effects on Turbocompressor Performance: Numerical Calculations and Measurement Data Evaluation

2020 ◽  
Author(s):  
Fabian Dietmann ◽  
Michael Casey ◽  
Damian M. Vogt
Keyword(s):  
Reynolds Number ◽  
Measurement Data ◽  
Theoretical Models ◽  
Design Flow ◽  
Flow Coefficient ◽  
Low Flow ◽  
Roughness Effects ◽  
Flow Channels ◽  
Compressor Performance ◽  
Low Flow Coefficient

Abstract Further validation of an analytic method to calculate the influence of changes in Reynolds number, machine size and roughness on the performance of axial and radial turbocompressors is presented. The correlation uses a dissipation coefficient as a basis for scaling the losses with changes in relative roughness and Reynolds number. The original correlation from Dietmann and Casey [6] is based on experimental data and theoretical models. Evaluations of five numerically calculated compressor stages at different flow coefficients are presented to support the trends of the correlation. It is shown that the sensitivity of the compressor performance to Reynolds and roughness effects is highest for low flow coefficient radial stages and steadily decreases as the design flow coefficient of the stage and the hydraulic diameter of the flow channels increases.

scholarly journals Flow Characteristics and Stress Analysis of a Parallel Gate Valve

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 803 ◽  
Author(s):  
Hui Wu ◽  
Jun-ye Li ◽  
Zhi-xin Gao
Keyword(s):  
Reynolds Number ◽  
Gate Valve ◽  
High Stress ◽  
Flow Characteristics ◽  
Groove Depth ◽  
Loss Coefficient ◽  
Flow Coefficient ◽  
Piping System ◽  
Valve Opening ◽  
Contact Position

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.

scholarly journals Experimental Study on Pressure Distribution and Flow Coefficient of Globe Valve

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 875 ◽  
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.

Transient Simulation of Flow Past Smooth Circular Cylinder at very High Reynolds Number Using OpenFOAM

2014 ◽  
Vol 592-594 ◽  
pp. 1972-1977 ◽  
Author(s):  
Sangamesh M. Hosur ◽  
D.K. Ramesha ◽  
Suman Basu
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Open Source ◽  
High Reynolds Number ◽  
Numerical Data ◽  
Flow Past ◽  
Computational Fluid Dynamics Cfd ◽  
High Reynolds ◽  
Set Up ◽  
Free Open Source

Flow past a smooth circular cylinder at high Reynolds number (Re=3.6 x 106) which covers the upper-transition regime has been investigated numerically by using Open source Field Operation and Manipulation (OpenFOAM) package. OpenFOAM is a free, open source Computational Fluid Dynamics (CFD) software package. The numerical model has been set up as two dimensional (2D), transient, incompressible and turbulent flow. A standard high Reynolds number k-ε turbulence model is included to evaluate the turbulence. The objective of the present work is to set up the case using pimpleFoam solver which is an Unsteady Reynolds Averaged Simulations (URANS) model and to evaluate the model for its conformance with available literature and experiments. The results obtained are compared with experimental and numerical data.

Simulation and Experimental Analysis of Diesel Fuel-Injection Systems With a Double-Stage Injector

1999 ◽  
Vol 121 (2) ◽  
pp. 186-196 ◽  
Author(s):  
A. E. Catania ◽  
C. Dongiovanni ◽  
A. Mittica ◽  
C. Negri ◽  
E. Spessa
Keyword(s):  
Fuel Injection ◽  
Injection Rate ◽  
Operating Conditions ◽  
Flow Coefficient ◽  
Injection System ◽  
System Component ◽  
Local Pressure ◽  
Pump Speed ◽  
Minor Losses ◽  
Set Up

A double-spring, sacless-nozzle injector was fitted to the distributor-pump fuel-injection system of an automotive diesel engine in order to study its effect on the system performance for two different configurations of the pump delivery valve assembly with a constant-pressure valve and with a reflux-hole valve, respectively. Injection-rate shapes and local pressure time histories were both numerically and experimentally investigated. The NAIS simulation program was used for theoretical analysis based on a novel implicit numerical algorithm with a second-order accuracy and a high degree of efficiency. The injector model was set up and stored in a library containing a variety of system component models, which gave a modular structure to the computational code. The program was also capable of simulating possible cavitation propagation phenomena and of taking the fluid property dependence on pressure and temperature, as well as flow shear and minor losses into account. The experimental investigation was performed on a test bench under real operating conditions. Pressures were measured in the pumping chamber at two different pipe locations and in the injector nozzle upstream of the needle-seat opening passage. This last measurement was carried out in order to determine the nozzle-hole discharge flow coefficient under nonstationary flow conditions, which was achieved for the first time in a sacless-nozzle two-stage injector over a wide pump-speed range. The numerical and experimental results were compared and discussed.

scholarly journals Investigation of mixing time in liquid under influence of rotating magnetic field

2017 ◽  
Vol 38 (4) ◽  
pp. 555-565
Author(s):  
Alicja Przybył ◽  
Rafał Rakoczy ◽  
Maciej Konopacki ◽  
Marian Kordas ◽  
Radosław Drozd ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Reynolds Number ◽  
Mixing Time ◽  
Rotating Magnetic Field ◽  
Homogenization Time ◽  
Set Up ◽  
The Relationship ◽  
The Magnetic Field

Abstract The aim of the study was to present an experimental investigation of the influence of the RMF on mixing time. The obtained results suggest that the homogenization time for the tested experimental set-up depending on the frequency of the RMF can be worked out by means of the relationship between the dimensionless mixing time number and the Reynolds number. It was shown that the magnetic field can be applied successfully to mixing liquids.

Effect of Schmidt Number on Dynamics of Particle-Driven Gravity Currents

2014 ◽  
Author(s):  
Tarun Chadha ◽  
Leonhard Kleiser
Keyword(s):  
Reynolds Number ◽  
Significant Influence ◽  
Schmidt Number ◽  
Fine Particles ◽  
Gravity Currents ◽  
Direct Numerical Simulations ◽  
Vorticity Field ◽  
Particle Properties ◽  
Flow Features ◽  
Set Up

Direct numerical simulations (DNS) of particulate gravity currents in a lock-exchange set-up are presented. The effect of the Schmidt number Sc on the current dynamics is analyzed by means of Eulerian-Eulerian simulations. Eulerian-Lagrangian simulations are used as a benchmark for assessing the results of Eulerian-Eulerian simulations. The Schmidt number Sc, the particle properties and the Reynolds number Re are varied. A significant influence of Sc was found, whose magnitude depends on the particle properties (being highest for fine particles) and on Re. For the finest particles used, the deposited particle mass was found to be different by almost 25% when comparing Lagrangian and Eulerian simulations with Sc = 1. The instantaneous flow features like the vorticity field are affected as well. When doubling Re, the effect was still found to be significant for finer particles, though less than that for low Re.

Electrically Conducting Neoprene and Rubber

1942 ◽  
Vol 15 (1) ◽  
pp. 146-157 ◽  
Author(s):  
B. J. Habgood ◽  
J. R. S. Waring
Keyword(s):  
Volume Resistivity ◽  
Acetylene Black ◽  
Development Work ◽  
Electrically Conducting ◽  
Rubber Compounds ◽  
Transverse Volume ◽  
Transverse Conductivity ◽  
Set Up ◽  
Longitudinal Resistivity ◽  
Conducting Rubber

Abstract (1) The scattered references in the literature dealing with conducting rubber have been collected together. (2) A résumé of existing ideas on the mechanism of electrical conduction is given, from which certain lines of development work suggested themselves. (3) Electrically conducting Neoprene or rubber compounds based on acetylene black are anisotropic, an effect which is particularly pronounced after extrusion. (4) By the use of fine channel black, either alone or in addition to acetylene black, the transverse conductivity is improved, thus reducing the anisotropy. (5) A further improvement can be obtained by using highly plasticized Neoprene or rubber which reduces the shear during extrusion operations. In the case of Neoprene, zinc oxide is omitted from the mixings to prevent set-up. (6) Conducting tubes having a transverse volume resistivity of 300 ohms per cu. cm., and a longitudinal resistivity of 60 to 70 ohms per cu. cm. have been obtained, using a potential difference of 6 volts. (7) Provisional methods of testing conducting rubber are suggested.

Reynolds Number Effects on Regenerative Pump Performance

1987 ◽  
Vol 109 (4) ◽  
pp. 392-395 ◽  
Author(s):  
J. W. Hollenberg
Keyword(s):  
Reynolds Number ◽  
Scaling Behavior ◽  
Flow Coefficient ◽  
Maximum Efficiency ◽  
Number Range ◽  
Design Point ◽  
Reynolds Number Range ◽  
Lower Reynolds Number ◽  
Reynolds Number Effects ◽  
Torque Coefficient

Reynolds number effects on the performance of a conventional design regenerative pump were investigated, using glycerine-water mixtures, between an impeller tip speed Reynolds number, RT, of 5.0×103 (all glycerine) and 1.6×106 (all water). Results show that the maximum efficiency, nm, can be expressed in terms of an output to loss ratio, nm/1−nm, which varies as RT0.203 for 2.0×104 < RT < 1.6×106 and as RT1.156 for RT < 2.0×104. These results are consistent with efficiency behavior reported in similar investigations on other types of turbomachines. Further, the design point flow coefficient increased over the range of Reynolds number investigated, while the design point head coefficient exhibited a maximum within this range. In addition, marked departure from scaling behavior occurred in the lower Reynolds number range. Finally, the correlation among torque coefficient, head coefficient, and flow coefficient previously established by the author was further verified and followed scaling behavior for the higher Reynolds number range.

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