To improve the performance of airbag gas generators a precise determination of velocities and temperatures of the streaming gases is necessary. This paper describes set up and test results of instrumentation which addresses this need, as it allows the simultaneous probing of velocity and temperature distributions of airbag gas flows. To obtain velocity and temperature information at a specified point in space, two optical techniques were combined. For temperature measurement the emission absorption method is used; velocity determination is accomplished via an optical velocimeter. As a prerequisite, both measuring methods rely on small particles, being imbedded in the gas flow. As most airbag gas generators produce the required particles by the combustion process themselves, this condition does not affect the methods applicability in air bag research. If combined with a pressure measurement, the described technique allows a full thermodynamic description of the gas flow. Experimental methods were presented which allow the temperature and velocity of airbag gas flows to be measured, simultaneously. Test results with different gas generator types are presented. Temperatures from 1200 K down to 500 K could be measured in the gas flow. Lower temperatures are accessible, if other wavelength-detector combinations are used. Higher temperatures require other wavelengths or refined electronics to be employed. The measured gas velocities range from about 500 m/s up to 1300 m/s. If combined with a pressure measurement, the described technique allows a full thermodynamic description of the gas flow.
Temperature and velocity measurements in airbag gasgenerator flows
Temperatur- und Geschwindigkeitsmessungen in den Strömungen von Airbag-Gaserzeugern
2006
9 Seiten, 7 Bilder, 2 Quellen
Conference paper
English
Temperature and velocity measurements in airbag gasgenerator flows
Automotive engineering | 2006
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