Optical Analysis of Rarefied Gas Mixture Flow Using a Laser

将q支宽带CARS应用于纯氮减压直流等离子体射流中的温度测量。在计算理论CARS剖面时，只考虑了多普勒展宽作为展宽参数，忽略了低压（6 Torr）引起的压力展宽。带水冷喷嘴的等离子体发生器产生相对低温的等离子体射流。在CARS光谱中不能观测到热带。由于弱激波的形成，等离子体射流中的温度沿中心线下游升高。随着放电电流的增大，整个流场的温度升高。提出了一种用双线激光诱导碘荧光法平面测量可压缩流体温度的方法。温度是由两束不同波长的激光束照射得到的荧光强度之比确定的。使用高灵敏度摄像机可以对流场中的温度进行多点测量。将该方法应用于超音速自由射流。发现B<-X跃迁中P(16)/R（18）和P(26)/R（28）吸收谱线的结果可以预测低于300 K的温度，精度<正负bbb50。本文用DSMC方法研究了氩氦混合物对向二维超音速自由射流相互作用区域的质量分离。假设氩气和氦气的混合比例为1:9。上游逆Knudsen数1/Kn范围为0.616 ~ 61.2，得到了氩、氦数密度和氩摩尔分数的空间分布。滞流区向外的流动由撇油器收集，撇油器与狭缝宽度相同，D，位于距离狭缝中心线2D处。在此条件下，氩气在1/Kn=25左右富集效果最佳。

The Q-branch broadband CARS is applied to measurement of temperature in reduced pressure DC plasma jets of pure nitrogen. In calculation of theoretical CARS profiles, only Doppler broadening is taken into account as a broadening parameter, neglecting pressure broadening because of low pressure (6 Torr). A plasma generator with a water-cooled nozzle produces a relatively low temperature plasma jet. Hotband can not be observed in the CARS spectra. Temperature in the plasma jet increases downstream along the centerline due to formation of the weak shock wave. And temperature rises over the entire flow field with discharge current.A method for planar measurement of temperature in a compressible flow by means of two-line laser-induced iodine fluorescence is proposed. Temperature is determined from the ratio of the intensities of fluorescence, which are obtained by irradiation of two laser beams of different wavelength. Use of of a high-sensitivity vidicom camera permits multiple-point measurements of temperature in the flow field. This method is applied to a supersonic free jet. It is found that the results obtained by P(16)/R(18) and P(26)/R(28) absorption lines in the transition of B<-X can predict temperature below 300 K with an accuracy of <plus-minus> 5Mass separation in the interacting region of opposed two-dimensional supersonic free jets of argon-helium mixture is investigated by use of the DSMC method. The mixing ratio of argon and helium is assumed to be 1 : 9. Spatial distributions of argon and helium number densities and argon molar fraction are obtained for the upstream inverse Knudsen numbers, 1/Kn, in the range of 0.616 to 61.2. Outward flow from the stagnant region is collected by a skimmer, which has the same width as the slit, D, and is located at a distance 2D from the slit centerline. For these conditions, argon is enriched effectively and the optimum separation effect is observed at about 1/Kn=25.