A new oh fluorescence signal-to-oh mole fraction conversion model formulation

In this work a non-linear model to reconstruct OH mole fraction profiles from a stand-alone experimental OH-PLIF fluorescence signal is provided. Starting from one-dimensional (1D) counter-flow flame solutions at different scalar dissipation rates and pressures for a syngas mixture, all the OH mole fraction profiles are normalized by their maximum value and made collapse into a single profile by using an exponential scaling factor. The collapsed profile is further reconstructed as the sum of a linear term and a non-linear error term. In this way, the OH mole fraction profile is entirely reconstructed in physical space. The absolute values of OH mole fraction are obtained by scaling the aforementioned profiles with the maximum value of the simulated OH mole fraction. The a priori estimation of the maximum OH mole fraction is obtained by a calibration function, which is built by correlating the simulated fluorescence and OH mole fraction maximum values. Finally, validation through 1D laminar counter-flow flames is given, and a comparison of model results for two different chemical kinetics mechanisms is examined and discussed.