Methodology for the application of velocimetry by molecular tagging of hypersonic flows

被引：0

作者：

Vialta, Leda Marise ^{[1
]}

Antonio de Souza Matos, Pedro ^{[2
]}

Barreta, Luiz Gilberto ^{[2
]}

Junior, Dermeval Carinhana ^{[1
,2
]}

机构：

[1] Aeronautics Institute of Technology, Sao Jose dos Campos, SP, Brazil

[2] Institute for Advanced Studies, Sao Jose dos Campos, SP, Brazil

来源：

Flow Measurement and Instrumentation | 2022年 / 88卷

关键词：

Flow velocity - Fluorescence - Hypersonic flow - Laser beams - Laser optics - Laser produced plasmas - Pulsed lasers - Velocimeters - Velocity;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

A laser-induced NO fluorescence technique was applied to measure velocity in a hypersonic shock tunnel nozzle exit. For the application of the technique, a detailed study of the density and fluorescence lifetime of the tracer radical, flow velocity and effective test time is proposed, resulting in a methodology for the application of the technique in hypersonic pulsed facilities. The study has demonstrated that it is necessary to jointly evaluate the flow velocity, the fluorescence lifetime of the radical and the width at half height of the laser beam, resulting in a kind of indicator for the feasibility of the technique. The variation of the laser incidence time with respect to the Pitot signal showed that it is not enough to select a stable Pitot pressure signal region to define the laser incidence time, preliminary trial and error analysis are necessary for each device used. Furthermore, the analysis of the velocity values calculated from the linear fit method shows that the adoption of such a method eliminates the effect of the systematic error of the measurements. © 2022 Elsevier Ltd

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