Measurement of air entrainment in plasma jets

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6431045

Fincke, J R; Rodriquez, R; Pentecost, C G

The concentration and temperature of air entrained into argon and helium plasma jets has been measured using coherent anti-Stokes Raman spectroscopy (CARS). The argon plasma flow field is characterized by a short region of well behaved laminar flow near the nozzle exit followed by an abrupt transition to turbulence. Once the transition of turbulence occurs, air is rapidly mixed into the jet core. The location of the transition region is determined by the rapid cooling of the jet and the resulting increase in Reynolds number. In contrast, the helium plasma flow field never exceeds a Reynolds number of 200 and remains laminar. The entrainment process in this case is controlled by molecular diffusion rather than turbulent mixing. 9 refs., 5 figs., 1 tab.

• Research Organization: EG and G Idaho, Inc., Idaho Falls, ID (USA)
• Sponsoring Organization: DOE/NE
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 6431045
• Report Number(s): EGG-M-89488; CONF-900520-1; ON: DE91001943; TRN: 91-000461
• Resource Relation: Conference: 3. national thermal spray conference and exposition, Long Beach, CA (USA), 21-24 May 1990
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
PLASMA JETS
ENTRAINMENT
SPRAY COATING
FABRICATION
HELIUM
LAMINAR FLOW
NOZZLES
RAMAN SPECTROSCOPY
REYNOLDS NUMBER
TURBULENCE
TURBULENT FLOW
DEPOSITION
ELEMENTS
FLUID FLOW
FLUIDS
GASES
LASER SPECTROSCOPY
NONMETALS
RARE GASES
SPECTROSCOPY
SURFACE COATING
360101* - Metals & Alloys- Preparation & Fabrication