Segmental orifice plates and the emulation of the 90°-bend

2020 ◽  
Vol 87 (1) ◽  
pp. 18-31
Author(s):  
Martin Straka ◽  
Christian Koglin ◽  
Thomas Eichler
Keyword(s):  
Near Field ◽  
Flow Conditions ◽  
Structural Element ◽  
Field Range ◽  
Flow Meters ◽  
Piping Systems ◽  
Approval Procedure ◽  
Electromagnetic Flow Meter ◽  
Coverage Rates ◽  
Water Meters

AbstractThe 90 ° - bend represents the most common structural element in piping systems and can have a significant impact on the measuring accuracy of flow meters installed downstream. Within the type-approval procedure of water meters, its impact is emulated by means of a segmental orifice plate with a segment area of 7 % (SOP7). In research and development, coverage rates of 33 % (SOP33) or more are sometimes used as an alternative. The purpose of this study is to evaluate the comparability of the flow conditions and their influence on the measurement deviation of flow meters, which is the basic requirement for using SOPs as a substitute for the 90°- bend. We present laser Doppler measurements downstream of an SOP33 and a 90°- bend and describe the flow development in a distance range from 2 to 30 diameters. Besides a quantitative comparison with performance indicators, the measurements are used to model the response of an ultrasonic and electromagnetic flow meter, including recent investigations of an SOP7. The results demonstrate the consistently poor agreement between the SOP7 and the 90°- bend, whereas the SOP33 provides similar flow conditions starting at a distance of 10 diameters. Further studies are necessary to develop a disturbance generator emulating the near-field range.

Research of the flow procedures in a pressure sewer system

2003 ◽  
Vol 47 (7-8) ◽  
pp. 351-356
Author(s):  
C. Dohse ◽  
H. Eckstädt
Keyword(s):  
Land Reclamation ◽  
Flow Conditions ◽  
Sewer System ◽  
Flow Meters ◽  
Initial Information ◽  
Pressure Pipe ◽  
Pumping Stations ◽  
Hydraulic Conditions ◽  
Measuring Section ◽  
The University

At the Institute of Land Reclamation, Hydrology and Sanitary Engineering of the University at Rostock the pressure and flow ratios are examined within a measuring section in the pressure dewatering system on the Darfl peninsula. The objective of the research project is the knowledge upgrade about the highly unsteady hydraulic conditions in a pressure sewer system. This paper firstly presents the method and the dimensioning of pressure dewatering systems, which can be done using either the peak effluent method or the statistical method; the examination program will be explained. The examination includes pressure difference measuring with two pressure meters and flow data measuring via magnetic-inductive flow meters. Additionally the pump running times of 15 pumping stations, as well as the compressor action of the pressure pipe rinsing station are continuously and temporarily recorded and saved. Finally the measuring results which provide initial information about the pressure and flow conditions in a pressure dewatering system will be presented. The effects of the rinsing, the low pressure differences, the air cushions, the seasonal differences as well as the daily development graphs of the wastewater production are all clearly visible.

Theory to Help the Use of Electromagnetic Flow Meters

2002 ◽  
Author(s):  
Xiao-Zhang Zhang
Keyword(s):  
Pipe Wall ◽  
Three Dimensional ◽  
Electromagnetic Properties ◽  
Reasonable Accuracy ◽  
Flow Meter ◽  
Flow Meters ◽  
Electromagnetic Flow ◽  
Gas Liquid Flow ◽  
Electromagnetic Flow Meter ◽  
Theory Research

Compared with other flow meters, the theory of electromagnetic flow meter is well developed. Until now, we are able to predict the three dimensional characteristics of this kind of flow meters with reasonable accuracy. This has given much help to the designers to improve the flow meters. On the other hand, the theory can offer a tool for the users of this kind of flow meters to judge the application situations, estimate the possible measurement error, etc. This paper introduces the recent work of the author on the theory of the electromagnetic flow meter. The basic physical conceptions and equations are given with a brief history review of the theory research. Several examples are given of using the theory to analyze the meters’ behavior in different application situations. They are: effect of the conducting pipe connections; errors caused by a pipe wall of different electromagnetic properties; gas-liquid flow and errors caused by a relative motion of the probe.

scholarly journals Development of a self-rechargeable digital water flow meter

2013 ◽  
Vol 15 (3) ◽  
pp. 888-896 ◽  
Author(s):  
Songhao Wang ◽  
Ronald Garcia
Keyword(s):  
Water Flow ◽  
Water Pressure ◽  
Communication Technologies ◽  
Turbine Generator ◽  
Flow Meter ◽  
Flow Meters ◽  
Pelton Turbine ◽  
Zigbee Technology ◽  
Diameter Pipe ◽  
Water Meters

The objective of this paper is to present the feasibility of a self-rechargeable digital water flow meter (SRDFM) system for water pipes using the latest data processing and wireless communication technologies while causing negligible water pressure drop (head loss). The system uses a Pelton turbine generator to power the electronic circuit, which processes and transmits the signals generated by several flow meters. ZigBee technology was used to process and send wireless signals. Signals from two water meters were acquired, processed, and transmitted with only one control/transmission unit during this study. The new system was assessed experimentally, reaching a maximum of 80 m of wireless transmittance distance at a minimum flow rate of 5 L/min for a 16-mm diameter pipe (self-charged).

Non-Destructive Detection of GIS Aluminum Alloy Shell Weld Based on Oblique Incidence Full Focus Method

2020 ◽  
Vol 1007 ◽  
pp. 105-110
Author(s):  
Xin Xin Wang ◽  
Cheng He ◽  
Pu Zhi Zhao ◽  
Yi Zheng ◽  
Shi Hao Jiang ◽  
...  
Keyword(s):  
Oblique Incidence ◽  
Near Field ◽  
Calibration Coefficient ◽  
Quantitative Detection ◽  
Imaging Method ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Field Range ◽  
Weld Defects ◽  
Non Destructive

In this paper, a new ultrasonic phased array full focus imaging method based on oblique incidence is proposed to solve the problem of the non-destructive testing of the internal defects in the GIS (gas insulated switchgear) shell welds. By using wedge coupling, the measured weld is far away from the near-field range of the transducer, and the detection angle range can be increased by changing the propagation direction of the acoustic beam. Based on Snell's law, the propagation characteristics of the ultrasonic wave in the interface are studied. On the basis of the conventional ultrasonic array matrix and the full focus imaging algorithm, by introducing the energy attenuation calibration coefficient of the acoustic wave propagation through the wedge, the correction amplitude of the specific focus point p(x, z) is obtained, The non-destructive testing of weld defects of GIS shell in the spot is carried out, and the test results show that the qualitative and quantitative detection of the weld defects can be well realized by using this method.

Experimental Study of Near-Field Entrainment of Moderately Overpressured Jets

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Stephen A. Solovitz ◽  
Larry G. Mastin ◽  
Farhad Saffaraval
Keyword(s):  
High Speed ◽  
Near Field ◽  
Flow Region ◽  
Flow Conditions ◽  
Entrainment Ratio ◽  
One Dimensional ◽  
Column Collapse ◽  
Developing Flow ◽  
Image Velocimetry ◽  
Velocity Flow

Particle image velocimetry (PIV) experiments have been conducted to study the velocity flow fields in the developing flow region of high-speed jets. These velocity distributions were examined to determine the entrained mass flow over a range of geometric and flow conditions, including overpressured cases up to an overpressure ratio of 2.83. In the region near the jet exit, all measured flows exhibited the same entrainment up until the location of the first shock when overpressured. Beyond this location, the entrainment was reduced with increasing overpressure ratio, falling to approximately 60% of the magnitudes seen when subsonic. Since entrainment ratios based on lower speed, subsonic results are typically used in one-dimensional volcanological models of plume development, the current analytical methods will underestimate the likelihood of column collapse. In addition, the concept of the entrainment ratio normalization is examined in detail, as several key assumptions in this methodology do not apply when overpressured.

scholarly journals Lidar Overlap Function Determination Using the Raman Lidar Signals

2020 ◽  
Vol 237 ◽  
pp. 07018
Author(s):  
Jaswant ◽  
Shishir Kumar Singh ◽  
Radhakrishnan S.R. ◽  
Devesh Shukla ◽  
Chhemendra Sharma
Keyword(s):  
Optical Properties ◽  
Simple Technique ◽  
Near Field ◽  
Lower Atmosphere ◽  
Raman Lidar ◽  
Lidar System ◽  
Field Range ◽  
The Mean ◽  
Overlap Factor

The determination of vertical distribution of optical properties of clouds and aerosols using the lidar system is affected by the incomplete overlap between the field of view of transmitter i.e. laser beam & the receiver in the near‐field range. Thus, the study of vertical profiles of aerosol optical properties in the lower atmosphere is erroneous without the correction of lidar overlap function. Here we have analysed the effect of overlap using a simple technique proposed by Ansmann and Wandinger to determine overlap function. We have determined the overlap factor for 5 different days of June 2016 and then calculated the mean overlap profile and determined the relative deviation of each day with respect to mean overlap factor. Results reveal that the complete overlap was achieved beyond 300 meters.

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