Rotational relaxation of nitrogen in ternary mixtures N2–CO2–H2O: Consequences in coherent anti‐Stokes Raman spectroscopy thermometry

The influence of CO2 and H2O on the rotational relaxation processes of N2 in ternary mixtures N2–CO2–H2O is investigated. The efficiency of these perturbers is responsible for significant modifications of the state‐to‐state relaxation rates and broadening coefficients. Flame data are well reproduced by taking into account these modifications. The role of these minor species in the determination of temperatures in premixed flames is analyzed. The present relaxation model allows us to understand why the discrepancy between observed and calculated coherent anti‐Stokes Raman spectroscopy (CARS) spectra in flames is sometimes resolved by empirically adding a dephasing component to pure nitrogen linewidths. Moreover, this model improves the accuracy of CARS temperature measurements.

[1]  G. Millot,et al.  Collisional line broadening and line shifting in N2-CO2 mixture studied by inverse Raman spectroscopy , 1990 .

[2]  W. Stricker,et al.  The application of CARS for temperature measurements in high pressure combustion systems , 1990 .

[3]  J. Hartmann,et al.  Line broadening, line shifting, and line coupling effects on N2–H2O stimulated Raman spectra , 1989 .

[4]  C. Boulet,et al.  State-to-state rotational phase coherence effect on the vibration-rotation band shape: An accurate quantum calculation for CO-He , 1989 .

[5]  L. Bonamy,et al.  Rotationally inelastic rates for N2–N2 system from a scaling theoretical analysis of the stimulated Raman Q branch , 1988 .

[6]  R. Clark,et al.  Advances in non-linear spectroscopy , 1988 .

[7]  G. Millot,et al.  Study of rotational relaxation fitting laws from calculations of SRS N2 Q-branch , 1987 .

[8]  R. Palmer,et al.  Comparison of rotationally inelastic collision models for Q-branch Raman spectra of N2 , 1987 .

[9]  M. Coltrin,et al.  Theoretical and experimental studies of high-resolution inverse Raman spectra of molecular nitrogen at 1-10 atm , 1987 .

[10]  R. Palmer,et al.  Studies of nitrogen self-broadening at high temperature with inverse Raman spectroscopy , 1986 .

[11]  G. Millot,et al.  Rotational collisional line broadening at high temperatures in the N2 fundamental Q-branch studied with stimulated Raman spectroscopy , 1986 .

[12]  D. Robert,et al.  Short range force effects in semiclassical molecular line broadening calculations , 1979 .