Mixing effects of Ar-H{sub 2} on the plasma characteristics of non-transferred DC plasma torches in the practical geometries

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:163118

Kang, K D; Ju, W T; Choi, B L; Hong, S H ^[1]

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1. Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering

Non-transferred DC plasma torches have been widely used as clean heat sources for material processings such as plasma spraying and synthesis. In this study, mixing effects of Ar-H{sub 2} on plasma characteristics in the non-transferred DC plasma torches at atmospheric condition are investigated by analyzing the voltage-current characteristics of arc discharge and the distributions of plasma flow field. Typical assumptions of steady state, axisymmetry, local thermodynamic equilibrium (LTE) and optically thin plasma are adopted in a 2-D magnetohydrodynamic (MHD) modeling of thermal plasma with a special treatment of electrical conductivity at low temperature. In order to reflect the geometrical shapes of the torch, the numerical calculations are performed in the body-fitted nonorthogonal coordinate system with covariant velocity components using Karki`s modified SIMPLER algorithm. The distributions of temperature, velocity, and current density in the various geometries of nozzle are calculated on the numerous operating conditions. One of the interesting results is that arc powers are rapidly increased and saturated as the flow rates of H{sub 2} gas are increased.

• OSTI ID: 163118
• Report Number(s): CONF-950612--; ISBN 0-7803-2669-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARGON
HYDROGEN
LTE
MATERIALS
PLASMA ARC SPRAYING
PLASMA GUNS
PLASMA JETS
PLASMA SIMULATION
S CODES
SYNTHESIS
TEMPERATURE DISTRIBUTION