Study of the possibility of high accuracy flow measurements with the pulsed neutron activation method
-
A. Nordlund
,
S. Avdic
Abstract
The performance of water flow measurements with pulsed neutron activation (PNA) have been investigated in the past few years. In this report the following particular Problems were investigated: (a) the effect of collimation on the time-resolved detector signals; (b) the behavior of the background signal, in order to expedite optimum background elimination from the measured signals; and (c) the properties of water mixing, by measuring the geometrical asymmetry of the activated volume as a function of distance from the source as well as of flow velocity. It was seen that with the flow velocities and Reynolds numbers in the present experiments, the mixing is not perfect. Thus, in general, the PNA method will lead to an underestimation of the mass flow due to the effect of the laminar layer close to the wall whose contribution to the total mass flow will be enhanced. The investigations reported here contribute to the improvement of the accuracy of the method.
Abstract
Die Durchführung von Strömungsmessungen mit Hilfe gepulster Neutronenaktivierung (PNA) ist in den letzten Jahren untersucht worden. In der vorliegenden Arbeit wurden insbesondere folgende Problemstellungen untersucht: (a) die Auswirkung der Kollimierung auf die Zeit-aufgelösten Detektorsignale; (b) das Verhalten des Hintergrundsignals; und (c) die Mischungseigenschaften von Wasser anhand von Messungen der geometrischen Asymmetrie des aktivierten Volumens als Funktion des Abstandes von der Quelle und der Strömungsgeschwindigkeit. Mit den Strömungsgeschwindigkeiten und Reynoldszahlen der gegenwärtigen Experimente konnte kein ideales Mischen erreicht werden. Deshalb unterschätzt diese Methode im allgemein den Massenfluss durch den Einfluss der laminaren Schicht nahe der Wand, deren Beitrag bei turbulenter Strömung vernachlässigt wird. Die vorliegenden Ergebnisse verbessern die Genauigkeit dieser Methode.
Acknowledgements
We would like to thank R. Rydz, L. Norberg and L. Urholm for their help and support with the experimental setup.
Thanks also to Prof. Imre Pázsit for valuable help and comments. The support by Göteborg Energi Forskningsstiftelse is acknowledged.
References
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© 2001 Carl Hanser Verlag, München
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Articles in the same Issue
- Frontmatter
- Calendar of Events
- Calendar of Events • Veranstaltungskalender
- Summaries
- Summaries/Kurzfassungen
- Notes
- Richtlinie VDI 3783 Blatt 12. Umweltmeteorologie – Physikalische Modellierung von Strömungs- und Ausbreitungsvorgängen in der atmosphärischen Grenzschicht – Windkanalanwendungen; Hrsg.: VDI Verein Deutscher Ingenieure, Kommission Reinhaltung der Luft (KRdl im VDI und DIN-Normenausschuss), Dezember 2000; 107,60 DM
- Comparison of plant efficiencies of various power conversion systems for high-temperature reactor modules
- Studies on the behaviour of a passive containment cooling system for the Indian Advanced Heavy Water Reactor
- Detonation waves in melt-coolant interaction
- Experimental study of the transient characteristics of a natural circulation loop under SBLOCA
- Calculation of the higher order eigenvalues for a homogeneous sphere using the FN method
- Books
- Safe Management of the Operating Lifetimes of Nuclear Power Plants
- Study of the possibility of high accuracy flow measurements with the pulsed neutron activation method
- The astrophysical S-factor for dd-reactions at keV-energy range
- Books
- Books • Bücher
- Monte Carlo analysis of accelerator-driven systems: Studies on spallation neutron yield and energy gain
- Subcritical nuclear systems and their stability against changes in the geometrical set-up
- Technical Notes
- An energy amplifier fluidized bed nuclear reactor concept
- An attempt to describe the swelling of U3Si 2 fuel by a simple formula
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- Patent
- Notes
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