Air Plasma Flow Simulation inside a Non-Transferred Well-Type Cathode Direct Current Torch at Different Pressures

• Main Authors: Shao-chu Hsu, 徐少駒
• Other Authors: Shiu-wu Chau
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/43528113323711524491

碩士 === 國立臺灣科技大學 === 機械工程系 === 101 === Based on steady and axis-symmetric assumptions, the continuity equation, current continuity equation, momentum equations and energy equation incorporated with the turbulence model are solved in this study by using a finite volume discretization in a segregated manner. The current distribution in the flow field is calculated by the Ampere's law and the magnetic field in space is predicted by the Ohm's law. For given anode position and assuming non-uniform current density at the cathode, the cathode spot is determined by fixing the measured voltage in the expreiments. The plasma flow in the region of pressure varing from 1 bar to 3 bars is calculated, where the flowrate increases from 100 L/min to 200 L/min and the working current ranging from 100 A to 200 A. The numerical results suggest that in the investigated cases, the maximum current density changes from A/m2 to A/m2, the arc length varies from 90 to 270 mm, the average temperature of the torch outlet alters from 3000 K to 6500 K, the average axial velocity of the torch outlet fluctuates from 20 m/s to 500 m/s and the average rotating velocity of the torch outlet varies from 1 m/s to 90 m/s.