A simplified approach to simultaneous multi-scalar imaging in turbulent flames

This communication describes and demonstrates an approach to making simultaneous multi-scalar measurements with reduced equipment requirements. Specifically, this letter describes and demonstrates the ability to simultaneously acquire high-quality planar laser-induced fluorescence (PLIF) images of CH₂O and either CH, OH, or a combination of CH and OH using a single Nd:YAG-pumped dye-laser system and two intensified cameras. Acquiring these images with common diagnostic equipment was facilitated by exciting strong transitions in the C–X (0,0) band of CH (near 314 nm) and in the A–X (0,0) and (1,1) bands of OH, which are spectrally adjacent. Additionally, Rayleigh scattering images were acquired simultaneously with these PLIF images using a second Nd:YAG laser and an un-intensified camera. However, it would be possible to conduct these measurements with a single, sufficiently energetic Nd:YAG laser.