Effect of the excitation line on hydroxyl radical imaging by laser induced fluorescence in hydrogen detonations
KAUST DepartmentClean Combustion Research Center
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
KAUST Grant NumberBAS/1/1396-01-01
Embargo End Date2023-03-19
Permanent link to this recordhttp://hdl.handle.net/10754/667722
MetadataShow full item record
AbstractThe present study aims to evidence the effect of the excitation line on the planar laser-induced fluorescence of hydroxyl radical (OH-PLIF) imaging in H-fueled detonation wave. We experimentally validated an updated laser-induced fluorescence (LIF) model, called KAT-LIF, which simulates spectrally-resolved fluorescence spectra, using a recently developed optical detonation duct. We numerically investigated the effects of the excitation line, the initial pressure (20–100 kPa), and the diluent (N/Ar) on the fluorescence spectrum, the spectrally- and one-dimensionally-averaged LIF intensity, and the quantitative capabilities of the OH-LIF measurements for different 2H-O-3.76diluent detonable mixtures. The investigated excitation lines were (0,0)Q1(7), both (1,0)Q2(8) and (1,0)Q1(9), and (1,0)Q1(6), which all belong to the transition. The main findings are the following: (i) considering the commercially available OH filters, Q2(8)+Q1(9) excitation scheme has the highest LIF intensity for all the investigated H-fueled detonations, while Q1(7) could provide the strongest intensity with better (custom) collection optics; (ii) the maximum LIF intensity decreases with increasing pressure for all the excitation schemes; (iii) using a single point calibration, at the fluorescence peak, it is not possible to perform quantitative measurements of OH radicals for any H-fueled detonation, using the conventional excitation schemes. Finally, we experimentally evidenced more favorable excitation schemes to obtain qualitative information far behind the front, by employing the saturated regime of fluorescence or the optically thin linear regime with appropriate laser configuration. These two excitation schemes correspond to more appropriate LIF strategies that will enable better detonation flow visualization in future studies.
CitationRojas Chavez, S. B., Chatelain, K. P., Guiberti, T. F., Mével, R., & Lacoste, D. A. (2021). Effect of the excitation line on hydroxyl radical imaging by laser induced fluorescence in hydrogen detonations. Combustion and Flame, 229, 111399. doi:10.1016/j.combustflame.2021.111399
SponsorsThis work was funded by the King Abdullah University of Science and Technology through the baseline funding (BAS/1/1396-01-01).
JournalCombustion and Flame