Collisional quenching corrections for laser-induced fluorescence measurements of NO A2Sigma(+)

Abstract

Quantitative combustion diagnostics using laser-induced fluorescence require a knowledge of energy transfer and quenching rates at elevated temperatures. Such information is critical both for experimental design and for subsequent reduction of measured signals to measurements of temperature and species concentrations. We present the results of a study of electronic energy transfer in NO A 2 S + . These results are cast in the form of empirical correlations which have been developed to facilitate the practical applications of quenching corrections. The choice of particular functional forms for these correlations is based on a classical collisional model of the process. This model has been calibrated against an extensive set of measured cross sections. Results are presented for a number of species of interest in combustion and aerothermodynamic applications.

Low-temperature collisional quenching of NO A2Σ+(v′ = 0) by NO(X2Π) and O2 between 34 and 109 K

“…Although the previously observed increase in quenching cross sections by NO(X 2 ) and O 2 at high temperatures is moderate and consistent with a harpoon mechanism, 22,23 in principle the second term in Eqs. (11) and (12) can describe any activated quenching process.…”

“…(12)]. In the fits, we included previous data up to 4515 K for NO and up to 2391 K for O 2 , 1,18,19,23 and the results are shown in Fig. 5.…”

Planar laser-induced fluorescence imaging of flame heat release rate

“…For example collisional quenching may exhibit a strong dependence on the identity of the collision partner or on temperature (e.g. NO A'Z' [7]), or with polyatomics like formaldehyde there is generally a strong temperature dependence through the Boltzmann fraction.…”

Visualization of Flowfield Modification by RCS Jets on a Capsule Entry Vehicle

“…These trends in the fluorescence intensity can be predicted using detailed spectral modeling. 16 In the future, we plan to use computational predictions of the flow along with the detailed spectral model to interpret differences that arise in fluorescence images and also to allow direct comparison between PLIF images and CFD. 14,17 E. Influence of Jet Pressure, P j on Leeward Aftbody Shear Layer Seeding pure nitric oxide from the topmost pressure port of the model forebody visualized the shear layer that formed between the gas passing over the model and the recirculating separated flow in the wake of, and adjacent to, the model.…”