Effects of Condensation on Gas Velocity in a Free-Jet Expansion
Abstract
An aerodynamic molecular beam has been used in an attempt to develop criteria for the determination of the onset of condensation in free-jet expansions of various gases. Measurements have been made of the total and monomer velocity distribution as a function of source pressure for the following conditions: (1) sonic orifice diameters of 0.0147, 0.0386, and 0.1245 cm, (2) source temperatures from 85 to 450K, (3) source pressures from 10 to 10,000 torr, (4) argon, nitrogen, oxygen, carbon monoxide, and carbon dioxide test gases, and (5) 20K skimmer and collimator surfaces. The variation of beam velocity with source pressure was characterized by an approximately constant value up to a particular pressure at which point the velocity started to increase. From a knowledge of the velocity increase and the properties of the gas, estimates of the fraction of condensate have been made. There are indications from some of the velocity measurements that contributions from evaporated or sublimated molecules may be affecting some of the velocity distributions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1973
- Accession Number
- AD0762503
Entities
People
- A. B. Bailey
Organizations
- Arnold Engineering Development Complex