【作者】 施建华； 姜宗福； 袁圣付；

【Author】 SHI Jianhua, JIANG Zongfu, YUAN Shengfu National Univ. of Defense Technology, Hunan, Changsha 410073

【机构】 国防科技大学理学院；

【摘要】 对国内外激光诱导荧光技术的发展现状进行了阐述,论述了用碘作为荧光物质的优越性。从荧光信号最原始的表达式出发,经过详细推导,合理的近似,得出:在流场充分混合、荧光的猝灭效应可以忽略的条件下,根据荧光强度与碘分子浓度成正比,可以测出流场的密度;利用碘分子吸收谱线的多普勒效应,通过设计合理的实验方案消除压强带来的频移,可求出流场的速度,将激发激光的谱线调到吸收谱线斜率最大的地方可以提高速度测量的精度;当流场的压强大于2000Pa时,通过比较两条不同谱线的荧光强度,可得到流场的温度;选择适当的荧光谱线,使得该条谱线的荧光信号随温度的变化可以忽略,则荧光强度只与压强成反比,流场的压强由此可得。更多还原

【Abstract】 The progress of Laser Induced Fluorescence(LIF) at home and abroad is expatiated and the advantages of using iodine as tracer are discussed. From the original formula of fluorescence, by deducing detailedly, with assumption in reason, the following conclusion was obtained. In the condition that the flowfield mix completely and the quenching effect can be ignored, the density of the flowfield can be measured by LIIF because the intensity of the fluorescence is proportional to it. The Doppler frequency shift of the absorption spectrum is the function of velocity, so the velocity of the flowfield can be acquired by getting rid of the frequency shift caused by pressure. The temperature can be obtained through comparing the signal of different rotational levels; By selecting the fundamental rotational level, the influence of temperature can be removed from the fluorescence signal, the pressure can be got because the fluorescence signal is inversely proportional to it.更多还原