Rayleigh and predissociative fluorescence imaging of total and quantum state-specific densities from a combustion bomb using tunable excimer laser light

摘要

Abstract: h Scattering (RS) and Planar Laser Induced Predissociative Fluorescence (PLIPF) are used to obtain 2-D images of total and of state specific $LB@i.e., of definite rotational levels of OH (v' $EQ 0) and O$-2$/ (v' $EQ 2, 3, 6, or 7)$RB densities of the burned and unburned zones inside a combustion bomb. A tunable excimer laser, operated in either the 193 nm- or 248 nm-range, is used. Our bomb is about the size of an automobile engine cylinder. As each volume element of the fuel mixture burns, it forms high-T products with large specific volumes. Because the thermodynamics are well known, the bomb may serve as a reference device for diagnostics for high temperature species via pulsed- laser methods. The total densities and the mole fractions of the various constituents can be accurately calculated. Work has been done with various compositions of hydrogen-air and propane-air fuel mixtures.!3