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...
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,...
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...
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.
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.
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.
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...
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...
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.
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...