IMEKO Event Proceedings

Author(s)
Title (as link)
Abstract
Event

R. Engel, H. J. Baade, Andreas Rubel
PERFORMANCE IMPROVEMENT OF LIQUID FLOW CALIBRATORS BY APPLYING SPECIAL MEASUREMENT AND CONTROL STRATEGIES
PTB's new ’Hydrodynamic Test Field’, which represents a high-accuracy water flow calibration facility, will serve as the national primary standard for flow measurands: volumetric and mass flow rate, respectively, and total flow measurement, i.e. the quantity of fluid (volume or mass) passing a flowmeter. Owing to this application aspect, the main design goal was to realize a total expanded measurement uncertainty as low as 0,02% for total volumetric flow-rate measurement. To meet this decisive requirement, low-uncertainty components were combined with state-of-the-art measurement and control strategies.
FLOMEKO 2003 – 11th Conference on Flow Measurement , Groningen, Netherlands, 2003

Christian Filips, Volker H. Hans
INTERACTION BETWEEN ULTRASOUND AND STREAMING FLUID IN VORTEX SHEDDING FLOW METERING
In the past in vortex-shedding flow meters pressure sensors in combination with big bluff bodies have been used. In the last few years the dimension of bluff bodies were reduced using ultrasound sensors due to higher sensibility. The frequency of periodically generated vortices are directly connected to the flow velocity. The signals are modulated in amplitude as well as in phase. The information are in the sidebands of the ultrasonic signal. Different carrier frequencies in combination with different dimensions of bluff bodies are examined.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Volker Hans
WHICH PHYSICAL QUANTITY OF TURBULENT STRUCTURES IS MEASURED IN CROSS CORRELATION FLOWMETERS?
Measurements of flow velocity with cross correlation functions of ultrasonic signals show that the travelling time of structures determined by the peak of the functions deviates from the average flow velocity. This difference usually is explained by the difference between line integral of measurement and area integral of the average flow velocity.
A comparison of the frequency distribution of single velocity components in the fluid determined by particle image velocimetry with the cross correlation measuring method shows that the most frequent components in the fluid are in accordance with the travelling time of structures measured by cross correlation. The physical explanation can be given by means of the impulse response.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Anton Fuchs, Bernhard Brandstätter, Bernhard Schweighofer, Georg Brasseur
MEASUREMENT OF VELOCITY AND MASS FLOW OF POWDERS
In this paper a cost-effective method for measuring transportation velocity and the velocity profile of a material flow of powdery solids inside a pipe is presented. For the measurement, artificial perturbations are brought into the mass flow and the effects of these perturbations are acquired and correlated at measurement sections. The velocity profile is calculated with the knowledge of the perturbation’s rheological decomposition and the sensitivity distribution of the measurement configuration.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Eddy Jacques, Pierre Wauters
PITOT-STATIC TUBE OR PITOT TUBE FOR MEASURING FLOW RATES?
Where volume flow rates in ventilation applications are to be measured common practise is to integrate the velocity profile over the entire cross-section. One of the instruments used to carry out the flow velocity traverse is the Pitot-static tube. The paper examines, on an experimental basis, whether the readings of both total and static pressure by a Pitot-static tube could not validly be carried out by a combination of a Pitot tube that measures the total pressure and tappings at the wall of the duct where the static pressure is picked up. The advantage becomes particularly interesting for applications where the flow rate may change in time.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Gregor Bobovnik, Jože Kutin, Ivan Bajsic
THE EFFECT OF DIFFERENT INLET-VELOCITY PROFILES ON THE PERFORMANCE OF A CORIOLIS FLOWMETER
Numerical simulations (using finite volume method) of the flow of a viscous fluid through a measuring tube were performed to identify the effects of different inlet-flow conditions on the performance of a straight, slendertube, Coriolis flowmeter. The magnitudes of the antisymmetric fluid forces and the twisting moments acting on the measuring tube were compared with results from a onedimensional fluid-flow model. Simulations were made for some hypothetical inlet-velocity profiles that represent extreme cases of various flowmeters’ installation positions and flow regimes in a pipeline. No significant effects of the modelled inlet-velocity profiles on the performance of the flowmeter were observed.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Takashi Moriyama, Shunsuke Fujiwara
CHLORIDE FILM SEPARATION IN GARBAGE AGAINST DIOXIN
This system already has Japanese Patent Application 2000-159699 using the blue light absorption and JPA2001-393262 using the thermal impedance for the chloride film detection in the garbage. We, human being have the three big ecological problems. The first is the nuclear waste in the northern part of the Japan Sea, the second is the irregular weather that will be less oxygen caused by carbon fuels and the third is Dioxins caused by the incineration of the chloride film and garbage.
The first and the second will be solved by the investment and stopping cars. The third is required for development of a automatic chloride film detector of the treatment for waste garbage plastics that is Sanuki RDF System against Dioxins. The first method is detecting the plastisizer in the chloride films of garbage and is not suitable for heated films by the wicro wave cooker. The plasticizer will go into the cooked food. The second thermal impedance method detects PVDC, PVC, heated PVDC, heated PVC and non chloride films.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Takashi Moriyama, Makoto Horio
CROSS CORRELATION MASS FLOWMETER USING PULSE HEATING
The aim of this study is the development of a novel nonintrusive mass flowmeter for the moved bed gravity flow of the new process, i.e.: the synthetic naphtha and hydrogen making reactor and DRI (Direct Reduction for Iron Ore) reducing petroleum and coke coal. One of the authors already developed cross correlation method, steady state heat transfer method and PZT acoustic emission method. This paper describes a prototype of a new cross correlation method using a pulse heating marking signal (JPA 1999-23339). The steady state heat transfer type is improved ale to ±0.8% full scale in this paper and it is the most available for the new process till the third oil crisis or reconstruction of coke. This new prototype should be more useful for the derivative temperature against choking the feed powder on the surface of the temperature sensors. .
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Marjo Lahti, Kalle Marjanen, Heimo Ihalainen
DETECTION AND CLASSSICATION OF AIR BUBBLE SILHOUETTES IN PIVIMAGES
A practical method for detection, segmentation and classification of the air bubble silhouettes in Particle Image Velocimeter (PIV) images is proposed. Air bubbles that are in focus plane have sharper edges and lower intensities than defocused bubbles. Detection and segmentation is based on estimating the local variances and comparing these with the local intensities. After detection and segmentation different statistics describing the size and shape of the bubbles can be measured. An example of using this method is provided.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Tuomo Timonen, Jouko Halttunen
EFFECT OF VARIATIONS IN A PULP FLOW ON SAMPLING AND PROCESS MEASUREMENTS
A pulp suspension flowing in a pipe has a tendency to form a profile: The properties of the pulp vary significantly in a cross-section of the flow. This causes problems both in online-measurements and sampling. The importance of representative sampling is further emphasized by the fact that samples taken are often used as reference in calibration of measurement instruments.
The problem of representative sampling and the variation of quality in a pulp flow were studied using equipment with which it was possible to take samples from different depths in the flow and thus determine the variations.
Experimental testing was conducted in different process conditions and with different pulp types. The results of the tests showed that the quality variations in a pulp flow were more profound than initially thought: Several pulp properties have significant profiles within the flow that depend on the type of the pulp and the flow conditions. The variation of pulp properties is large enough to somewhat affect all measurements made from the flow in question.
The findings of the study suggest new guidelines for sampling and installing instrumentation when a pulp suspension flow is measured.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Ernst von Lavante, Burger Nath, Jörg Färber
EFFECTS OF MANUFACTURING TOLERANCES ON THE ACCURACY OF VORTEX-SHEDDING FLOW METERS
In the present investigation, the problem of accurate determination of volumetric flows by means of the so-called vortex-shedding flowmeter in the case of shape changes and deviations of the geometry from the original specifications due to manufacturing tolerances and imperfections was studied. To this end, the flow about the bluff body used in the presently studied vortexshedding flow meter was numerically simulated using a solver of the unsteady, compressible (air) or incompressible (water) Navier-Stokes equations in two and three dimensions. The computations were carried out for several types of modified geometry including a slightly rotated bluff body, rounded edges representing wear and asymmetrically oriented sensor body called here "paddle". The results were compared, where possible, with experimental data obtained by the manufacturer. The effects of turbulence were modeled by using the realizable k-ε turbulence model. The resulting flow fields were analyzed using various methods, including visualization, evaluation of several of their global features and DFT of properly chosen variables.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Florian Maier, Bernhard G. Zagar
EXPERIMENTAL ULTRASONIC FLOW MEASUREMENT IN SMALL CAPILLARIES
In this paper we present preliminary results of an ultrasonic flow measurement set-up designed to accurately measure the flow velocity profile of blood mimicking fluid pumped through a capillary flow phantom even under the deteriorating effects of clutter and noise always seen in medical ultrasound applications. The measurement system is set up in a way to acquire and display 3-dimensional velocity and/or topological data.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Milan Adámek, Miroslav Matýsek, Petr Neumann
SMALL GAS FLOW MEASUREMENTA MICROCOMPUTER APPLICATION
This paper presents a flowmeter design applicable for measurement of low gas flow amounts. The designed flowmeter with a time–of–flight sensor represents a microcomputer application with a control and evaluation procedure. The mathematical model of energy and temperature balance is simulated in the FEMLAB environment. The designed measurement device was used for research of a reaction kinetics of biodegradation reactions successfuly.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Mihail Radu Patrascoiu
PROPOSED METHOD FOR GAUGE CALIBRATION BY A SERIES EXPANSION SYSTEM AT NML–CSIR, SOUTH AFRICA
There are various types of series expansion systems around the world, offering high accuracy for calibration of standards. The method investigated in this paper considers a much simpler system with a higher degree of certainty in measurements. The novelty of the method does not offer a new calculation, but rather a muchsimplified design Instead of using a high number of vessels, where the gas expands into, the system is limited to only two. The uncertainties will relate only to the pressure reduction factors or volume ratios and other known external factors.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Andrej Predin, Ignacijo Biluš
SECONDARY FLOW MEASURING AT THE RADIAL FAN ENTRANCE
Analyze is given of different measuring methods relating to the prerotation flow in the entrance pipe of the radial pump. The appearance of the prerotation flow is a result of complicated fluid flow model, which appears as a consequence of the pump operating out of design point and reduce the pump efficiency. The goal of this contribution is in estimating the adequate measuring method, taking into account the inconvenience of conventional Laser – Doppler anemometry. Therefore, two measuring methods – multiblade (ASB) and single blade anemometer (ASSB) are introduced, analyzed and compared with well known 2 channel hot wire anemometry (HWA). The advantages of the introduced measuring system - ASB are in its simple construction and simple use and its low price. Direction and the swirl flow intensity in the entrance pipe of radial pumps and fans, using this method, could be measured.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Nastia Degiuli, Andreja Werner, Zdravko Doliner
EXPERIMENTAL DETERMINATION OF WAVE PATTERN RESISTANCE OF A TRIMARAN
The experimental determination of wave spectra and wave resistance from measurements of the wave pattern behind a ship model while being towed in a tank received considerable attention in the sixties and seventies. The Landweber, Hogben and Baba methods of experimental determination of wave pattern resistance based on wave height measurements in several longitudinal measurement cuts have been introduced in this paper. The programme of experimental determination of wave pattern resistance has been carried out in DINMA-Trieste for a trimaran whose individual hulls are Wigley parabolic models, for the Froude number range 0.254-0.420, with a total of 12 runs. The above mentioned methods are based on identical hydrodynamic model, and a starting basis are identical analytic expressions. By experimental determination of wave pattern resistance, a comparison of the calculation results (amplitude spectrum, wave resistance, reconstructed waveforms) is given. It has been shown that all three methods are equal and that they give the same results if the criteria based on frequency content determination and resolution in frequency are respected.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

Tihomir Mihalic, Tomislav Stašic, Nastia Degiuli
UPGRADING OF A BELL PROVER
Bell provers have a wide usage for calibrating various types of flow meters by timing the bell ascendance. They are often used as a working standard. Known area of the bell along with measured displacement of the bell produce, with some measurement uncertainty, volume generated by the bell. This volume with measured time gives the flow generated by the bell.
The temperature and the pressure of the gas in the bell are not constant. Further more the temperature and the pressure at the flow meter are not equal to those in the bell due to losses in pipes. Because of that it is imperative to measure all of them. When those measurands are stored in database entire measurement can be analyzed at referent conditions.
In order to automate measurements with the bell prover, to improve the measurement uncertainty of the results, and to obtain some additional quantities like velocity and acceleration of the bell, computerized measurement equipment has been installed on the bell prover.
XVII IMEKO World Congress, Dubrovnik, Croatia, 2003

P R O C E E D I N G S

Year of event

TC

Event

Authors/Title

Keyword(s)

Abstract