An experimental study of the wall characteristics of a local fluid constriction plasma generator

A local energy conversion efficiency for a confined-discharge plasma generator is defined as the fraction of local power input which is transferred to the gas. The local efficiency is a maximum near the gas inlet and diminishes with axial distance. The thermal development length is the axial extent of that region in the plasma generator duct where the local efficiency is nonzero. This length varies with mass flow rate, current, and duct diameter. Nondimensionalization of the energy equation results in a dimensionless S parameter which determines the thermal development length. The S parameter is the product of mass flow rate, electrical conductivity, enthalpy, and duct diameter divided by the arc current squared. The thermal development length is the product of two times the S parameter and the duct diameter. Below-atmospheric static pressures occur when a calorimeter is installed at the generator plasma exit. These pressures result from deceleration of the plasma in the calorimeter. Empirical expressions for enthalpy and electrical conductivity as functions of current and mass flow rate are substituted into the S parameter, allowing the parameter to be evaluated directly from the mass flow rate and current. The S parameter is effective in evaluating redevelopment thermal lengths downstream of local radial fluid injection into the plasma. Also, the S parameter is found to be effective in evaluating thermal development lengths of independent data from a previous investigator.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1973

Author dc:creator

• Smith, Wayne Lee

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/76137

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/76137