Zusammenfassung
Die Eignung eines Ultraschall-basierten Gas-Durchflussmessers (Laufzeitprinzip) kann bezüglich des Gastemperaturbereichs erweitert werden (bis zu 450 °C). Mit Hilfe von Methoden der numerischen Strömungsmechanik und Schallstrahlsimulationen untersuchten wir thermisch bedingte Effekte, welche die Schallausbreitung innerhalb des Durchflussmessers beinflussen. Dadurch konnten die Geometrie und die Betriebsart des Durchflussmessers optimiert werden. Die präsentierten Ergebnisse belegen, dass ein solcher Durchflussmesser für die Messung einer pulsierenden Gasströmung über einen weiten Temperatur- und Strömungsgeschwindigkeitsbereich verwendet werden kann. Ein Anwendungsbeispiel ist der Abgasstrang eines automobilen Verbrennungsmotors.
Summary
The applicability of an ultrasonic transit-time gas flowmeter can be extended regarding its gas temperature range (up to 450°C). We used computational fluid dynamics and ray-tracing techniques to investigate thermally-related effects that influence the sound propagation inside the flowmeter. This allowed us to optimize the geometry and the method of how to operate the flowmeter. Our results prove that such a flowmeter can be used to measure pulsating gas flows over wide temperature and velocity ranges such as found in the exhaust gas train of an automotive combustion engine.
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Kupnik, M., Gröschl, M. Ultrasonic-based gas flowmeter for harsh environmental conditions. Elektrotech. Inftech. 126, 206–213 (2009). https://doi.org/10.1007/s00502-009-0638-0
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DOI: https://doi.org/10.1007/s00502-009-0638-0