直流纯氮层流等离子体射流特性的实验研究

采用自行研制的直流非转移型等离子体发生器,对其产生的层流等离子体射流特性进行了实验研究。实验结果表明:该等离子体发生器在以纯氮气为工作气体时,呈现出高电压低电流的等离子体射流特性,该特性有助于提高等离子体发生器的电极寿命;在弧电流和工作气流量由小向大变化过程中,等离子体射流长度均呈现出先由短变长、再由长变短的变化规律;在等离子体射流长度由长变短的过程中,射流的形貌从相对集中、轴对称和稳定的状态向分散、非轴对称和不稳定的状态变化,即等离子体射流由层流形态向湍流形态转变,并且在此过程中射流产生的噪音逐渐增强。

Experimental study on characteristics of direct-current laminar-flow nitrogen plasma-jet

Aiming at providing new experimental results on the characteristics of the nitrogen laminar plasma jet, experiments were carried out with the laminar plasma jet generated by a self-developed direct-current (DC) non-transfer plasma generator. The experimental results show that the plasma jet, generated by the plasma generator using nitrogen as the working gas, presents a characteristics of high voltage and low current. Such characteristics are helpful for improving the electrodes lifespan of the plasma generator. As the arc current and gas flow rate increase, the length of the plasma jet varies from short to long, and then from long to short. As the length of plasma jet decreases, the morphology of plasma jet changes from relatively concentrated, axisymmetric and stable state to a scattered, non-axisymmetric and unstable state. In other words, the plasma jet changes from laminar to turbulent state. In addition, the noise from the plasma jet gradually increases during this process