层/湍流等离子体射流波动特性实验研究

本文应用电压传感器、光电倍增管及水冷皮托管,对产生射入空气中的纯氩层流和湍流等离子体射流的弧电压波动、发生器出口处的射流光强波动以及沿射流轴线的滞止压力波动进行了测量。结果显示层流等离子体射流各参数的波动幅度远小于湍流射流的对应值;弧电压的波动幅度随气流量的变化明显,但随电流的变化很小;弧电压的波动幅度与其平均值之比随电流增加呈下降的趋势。

EXPERIMENTAL STUDY ON FLUCTUATION CHARACTERISTICS OF LAMINAR/TURBULENT PLASMA JETS

Fluctuations of arc voltage in generating DC pure-argon laminar/turbulent plasma jets issuing into the atmosphere, and responses of light intensity in the jet at torch exit and local stagnation pressure along the jet axis were measured separately by using voltage sensor, photo-multiplier and water-cooled pitot tube. Results show that fluctuation amplitudes of all the measured parameters in laminar jets are much smaller than those in turbulent ones. The fluctuation amplitude of arc voltage changes appreciably with the change of gas flow rate, while it shows little difference with the change of arc current; the ratio of the voltage fluctuation to the mean voltage decreases with the increase of arc current.