直流减压层流氩等离子体射流的温度测量

在低于大气压条件下产生的减压热等离子体射流仍然具有较高的温度和能流密度,已经有几十年的材料工艺应用历史,但是对减压热等离子体射流的参数诊断、特别是对其可能偏离局域热力学平衡的特性研究还远未深入和系统。本文采用玻尔兹曼图表法及双静电探针方法,对以纯氩为工质的减压层流热等离子体射流的激发温度及电子温度进行了测量

Fluctuations in a direct current argon plasma jet at reduced pressure

Dynamic measurements of the ion saturation current in the plasma plume by a double-electrostatic probe system were carried out. Regular signals obtained by the electros- tatic probe show good agreement with the stable plasma flow state. Dependence of the flow steadiness on the plasma generation parameters was discussed. As a fast response method, the double-electrostatic probe system is feasible to characterize the fluctuations in the plasma jet

Flow Velocity Measurement in a Non-Transferred DC Arc Plasma-Jet by Using Electrostatic Probes

组建了一套利用静电探针诊断技术测量减压直流非转移弧等离子体射流速度的实验系统.对以纯氩为工质的等离子体,在气流量1.25×10~(-4) kg/s、弧电流80A、真空室压力165 Pa的条件下,测量了射流的速度及其分布.结果表明射流在发生器出口处中心最高速度约为1 200 m/s,在半径20 mm处减小到635 m/s.沿射流轴线方向的速度梯度约为10 (ms~(-1))/mm.射流速度随着弧电流增加而缓慢单调增加;当真空室压力从165 Pa提高到2 kPa时,发生器出口轴线上的射流速度从1200 m/s降至570 m/s

Fluctuations of Arc Voltage and Jet Flow in Non-Transferred DC Plasma at Reduced Pressure

实时测量了减压直流纯氩等离子体的弧电压和射流高温区的瞬时离子饱和电流. 结合射流高温区的瞬时形貌, 探讨了在真空室压力500~10000 Pa条件下电弧及等离子体射流的波动特性. 结果表明:当气流量较小和真空室压力较低时, 射流流场呈现较好的稳定性. 随着气流量和真空室压力增加, 弧电压出现高频脉动, 射流能量分布的空间和时间稳定性逐渐变差, 离子饱和电流信号变得紊乱;即使由于电源特性引起电弧功率300 Hz的波动幅度高达35%, 依然能够产生流场较稳定的等离子体射流;静电探针检测等离子体射流的瞬时离子饱和电流可作为了解射流波动特性的一种快速响应方法

Electron Temperature Measurement of a Reduced-pressure arc Plasma jet by Using Double-electrostatic-probe

建立了一套双静电探针诊断系统,用于检测在气流量为4.2 slm、弧电流为80 A、真空事压力为165Pa的条件下纯氩直流非转移弧等离子体射流的电子温度及其分布.结果表明:发生器出口处射流中心的电子温度约为14 500 K,射流中电子温度随离开发生器出口的轴向或径向距离的增加而单调降低;径向电子温度梯度约为263 K/mm,轴向电子温度梯度为69 K/mm;射流中电子温度随弧电流增加而单调上升

Instabilities in a non-transferred direct current plasma torch operated at reduced pressure

Using an oscilloscope, a high-speed video camera and a double-electrostatic probe system, the periodicity and amplitude of the fluctuations in arc voltage, jet luminance and ion saturation current of a plasma jet were monitored to investigate various sources of instabilities and their effects in a non-transferred dc plasma torch operated at reduced pressure. The results show that besides a 300 Hz main fluctuation inherited from the power supply, arc voltage fluctuation of 3–4 kHz with an amplitude less than 5% of the mean voltage was mainly affected by the total gas flow rate. The arc voltage fluctuation can affect the energy distribution of the plasma jet which is detectable by electrostatic probes and a high-speed video camera. The steadiness of energy transfer is also affected by the laminar or turbulent flow state of the plasma

有机物性估算系统OPES微机版本的研制（Ⅱ）软件的开发与特性

本文主要介绍有机物性估算系统ＯＰＥＳ（ＯｒｇａｎｉｃｐｈｙｓｉｃａｌＰｒｏｐｅｒｔｙＥｓｔｉｍａｔｉｏｎＳｙｓｔｅｍ）微机版本的软件特性。ＯＰＥＳ的总体结构采用将输入、输出与物性估算程序完全分离的策略：实现了系统的有效分解；物性估算程序的进一步分解则有效地解决了在ＤＯＳ环境下开发大型应用程序所面临的内存使用问题；标准化模块的设计思想既提高了软件的开发效率，又方便了今后软件的维护。本文从基础物性数据库检索方法的选择、用户界面的灵活性与智能性、系统的透明性、系统的健壮性等方面介绍了ＯＰＥＳ的使用功能。＊Ｃｏｍｐｏｎｅｎｔ：１＊２４Ｏ５Ｃ３Ｈ３Ｎ１Ｏ７－１３－１（依次是：丙烯腈的ＩＤ号、分子式、ＣＡ登录号）ＣＨ２＝ＣＨＣ＊Ｎ（丙烯腈的ＯＣＳＣＥ线性码）ａｃｒｙｌｏｎｉｔｒｉｌｅ（丙烯腈的英文名）Ｔ２（温度点数为２，温度分别是２９３。１５Ｋ，４５０．００Ｋ）２９３．１５Ｋ４５０．００ＫＰＯ（没有输入压力，压力点数为０）ＰＨ２（相态为液态）ＰＯ３（极性类别是强极性）ｂａｓｉｃｄａｔａｏｆｃｏｍｐｏｎｅｎｔＮｏ．１（从基础数据库中查到的数据）ＳＴＲＣＨ２＝ＣＨＣ＊ＮＲＭ５３．０６００（ｇ／ｍｏｌ）Ｓ（分子量，质量码Ｓ