多线羟基标志测速技术用于反应和非反应实验流体
A new compact micro-lens optical system has been developed to produce a 7 x 7 multiline optical grid for Hydroxyl Tagging Velocimetry (HTV). These lines provide additional spatial information and aid the software tracking of the flowfield by increasing its resolution. Single-photon photodissociation of groundstate H2O by a ~193-nm ArF excimer laser “writes” a 7x 7 beam molecular grid with very long gridlines of superequilibrium OH and H photoproducts in either room air flowfields or in H2-Air flames due to the presence of H2O vapor. The displaced OH tag lines’positions are revealed through fluorescence by A2Σ + (v′ = 0) ← X2Π i (v″ = 0) OH excitation using a ~308 nm pulsed frequency-doubled dye laser. A time-of-flight software (DaVis 6.0 Stereo PIV/PTV, LaVision,GmbH) determines the instantaneous velocity field. HTV tag lifetime comparisons between experimental results and theoretical predictions are discussed.