Fluid Mechanical Characteristics of Microwave Discharge Jet Plasmas　at Atmospheric Gas Pressure

Fluid mechanical properties of microwave discharge jet for argon and helium plasmas at atmospheric gas pressure is investigated. Kelvin-Helmholtz(K-H) instability due to shear flow of working gas with surrounding air is seen to reflect on the plasma structure. Pulsation phenomenon for helium plasma jet is found not to have a counterpart in gas fluid behavior. Flickering phenomenon is shared in both jet diffusion flame and plasma jet. Ascending flow due to buoyancy effect and convection surrounding air to be followed by vortex formation originated from K-H instability would be the physical mechanism for the flickering