On the efficiency of using different excitation lines of (1-0) two-line OH fluorescence for planar thermometry
A.S. Lobasov1,2, R.V. Tolstoguzov1,2, D.K. Sharaborin1,2, L.M. Chikishev1,2, V.M. Dulin1,2
1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
Keywords: planar thermometry, laser-induced fluorescence, hydroxyl radical
Abstract
The paper presents the results of simulation and experimental study on the efficiency of selecting a pair of excitation lines of OH hydroxyl radical for the (1-0) transition for the A2Σ+-X2Π system for local temperature measurement in a hydrocarbon flame. The LASKIN software was used for the numerical simulation. The temperature field for a laminar methane-air premixed flame (with equivalence ratio equal 1.1) at the atmopsheric pressure was measured. Different combinations of literature-recommended pairs of excitation lines were considered. The results of numerical simulation agree with a theoretical dependency for the temperature range of 1200 - 2100 K for the coupled excitation lines Q1(5):Q1(14) and Q1(5):Q2(11). However, a moderate discrepancy is observed for the pairs R2(2):R2(13) and R2(2):R2(10). It is concluded that the coupled excitation of Q1(5):Q1(14) and R2(2):R2(13) lines provide a higher sensitivity to the temperature variation. The benefit of the latter pair is that these transitions correspond to close values of the excitation wavelengths in the vicinity of 282 nm. Therefore, this can be convenient for the arrangement of experiments.
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