| Zugriffsnummer | 19601 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | The use of micro-nozzles under sonic and subsonic conditions with various gases |
| Autor(in); Institution |
Mickan, Bodo; 1.4, Gase, PTB-Braunschweig
Kramer, Rainer; 1.4, Gase, PTB-Braunschweig
Dopheide, Dietrich; 1.4, Gase, PTB-Braunschweig
|
| Quelle/Jahr | Fluid flow measurement : 6th international symposium, May 16th - 18th, 2006, Queretaro, Mexico ; proceedings:(2006) |
| Availability | [CD-ROM] |
| Herausgeber(in) |
North American Fluid Flow Measurement Council
|
| Verlag | Queretaro: |
| Konferenzangaben | 6th International Symposium of Fluid Flow Measurement, Queretaro, 16-18, May, 2006, Mexiko |
| Freie Schlagworte | Micro-Nozzles ; Various Gases |
| Zusammenfassung | The use of critical nozzles as secondary flow standards and transfer standards became more and more important in the recent years. Also the minimum size of nozzles (or the flow rate respectively) used for such purposes decreased in the same time more and more. Actually the smallest nozzles are in the range of some micro meters for the throat diameter. Fact is that micro-nozzles needs a high back pressure ratio to operate with sonic (critical) conditions at the throat. In prectice it is not always possible to reach this conditions. The paper presents measurements with such nozzles under sonic as well as subsonic conditions at the throat using a set of various gases. The resulting flows can be approximated by a very simple modification of the conventional flow rate calculation of critical nozzles. The modifination bases on an appropriate normalization with values derived from pressures, speed of sound and isentropic exponent. Finally it allows to use a nozzle as secondary or transfer standard in a flow rate range of 1:10 at least. |
