Experimental and Numerical Analysis of Narrowband Coherent Rayleigh-Brillouin Scattering in Atomic and Molecular Species (Pre Print).

摘要

Coherent Rayleigh-Brillouin scattering (CRBS) lineshapes generated from an all narrow-band pump experiment, a Direct Simulation Monte-Carlo (DSMC) approach, and published simplified models are presented for argon, molecular nitrogen, and methane at 300 & 500 K and 1 atm. The simplified models require uncertain gas properties, such as bulk viscosity, and assume linearization of the kinetic equations from low intensities (<1 x 1015 W/sq m) operating in the perturbative regime. DSMC, a statistical approach to the Boltzmann equation, requires only basic gas parameters available in literature and simulates the forcing function from first principles, without assumptions on laser intensity. The narrow band experiments show similar results to broadband experiments and validate the use of DSMC for the prediction of CRBS lineshapes.