本研究在假設二維軸對稱及穩態的條件下進行非傳輸型井式陰極直流空氣電漿火炬流場模擬分析，利用有限體積法聯立求解連續方程式、電流連續方程式、動量方程式、能量方程式與紊流模型，流場內的電流分布利用安培定律求得，而流場內的磁場大小則是利用歐姆定律決定，藉此分析電漿火炬內部電漿氣體流場基本特性。本研究基於給定陰極弧根位置以及非均勻分布電流密度，利用實驗電壓值進行陽極位置的估算，並比較在不同壓力下流量與電流對流場特性的影響。本研究中所使用的工作壓力為1 bar、2 bar及3 bar，空氣流量範圍為100 L/min至200 L/min間，工作電流範圍為100 A至200 A間。計算結果顯示陰極最大電流密度大約介於 A/m2與 A/m2間，電弧長度範圍約在90至270 mm間，出口處平均溫度範圍約在3000 K至6500 K間，出口處平均軸向速度範圍約在20 m/s至500m/s間，出口處平均旋向速度範圍約在1 m/s至90m/s間。

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.

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