Experimental measurements of plasma properties for Miller SG-100 torch with Mach I setting
- Minnesota Univ., Minneapolis, MN (United States)
In this work measurements of plasma properties, including the fields of temperature, velocity and plasma composition have been completed for the Miller SG-100 plasma torch using argon-helium mixtures with the Mach 1 nozzle at 1 atm pressure. A computer-controlled system combining both spectroscopic and enthalpy probe diagnostics has been developed to allow temperature measurements covering a range from 2000--16000K which includes the plasma flame region which is of interest. The experimental results expose the dominant effects in different spatial areas of argon-helium plasma jets. In the center near the nozzle exit the temperatures exceed 10,000K, and strong diffusion exists due to the steep radial gradients of temperature and particle number densities. In the jet tail region where the temperatures are well below 10,000K and decay in axial and radial direction, the dominant effects in this area are strong cold gas entrainment associated with turbulence. Substantial discrepancies between temperatures evaluated from spectroscopic and enthalpy probe data are particularly severe in the jet fringes indicating that strong deviations from LTE may exist in the jet fringes. In addition, entrainment of the cold surrounding gas into the plasma jet causes severe discrepancies between spectrometric and enthalpy probe data. The validity of the two diagnostic methods will be discussed. The temperature profiles in argon-helium plasma jets are flatter and wider, and the velocities are higher than in a pure argon plasma jet. These features of argon-helium plasma jets may be beneficial for obtaining better performance in the plasma spraying process. 26 refs., 28 figs., 2 tabs.
- Research Organization:
- EG and G Idaho, Inc., Idaho Falls, ID (United States); Minnesota Univ., Minneapolis, MN (United States)
- Sponsoring Organization:
- DOI; Department of the Interior, Washington, DC (United States)
- DOE Contract Number:
- AC07-76ID01570
- OSTI ID:
- 6249735
- Report Number(s):
- EGG-SCM-9576; ON: DE92003309; CNN: J0134035
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
42 ENGINEERING
420400 -- Engineering-- Heat Transfer & Fluid Flow
ARGON
ELEMENTS
ENERGY TRANSFER
ENTHALPY
FLUIDS
GASES
HEAT TRANSFER
HELIUM
NONMETALS
PHYSICAL PROPERTIES
PLASMA JETS
RARE GASES
SPECTROSCOPY
TEMPERATURE MEASUREMENT
THERMAL ANALYSIS
THERMODYNAMIC PROPERTIES
ULTRAHIGH TEMPERATURE
VELOCITY