Monte Carlo calculations of reaction rates and energy distributions among reaction products. Reactions of HF and DF with H and D-atoms

Abstract

Rate coefficients are calculated for the reactions of H and D-atoms with vibrationally excited HF and DF molecules. Three-dimensional classical trajectories of the collision dynamics of these reactions have been calculated by means of the London-Eyring-Polanyi-Sato (LEPS) potential energy surface. The Monte Carlo procedure is used to start each collision trajectory. Results of this study indicate that (a) chemical exchange provides an efficient mechanism for relaxing vibrationally excited HF and DF molecules by H and D-atoms ; (b) multiple-quantum transitions are important in the deactivation processes; and (c) both vibration-translation and vibrationrotation energy transfers contribute to vibrational relaxation of vibrationally excited HF and DF molecules by H and D-atoms. The vibrational relaxation of HF (v = 1) by H-atoms is faster than the vibrational relaxation of DF (v=l) by H-atoms. A similar effect is indicated for D-atoms; i.e. the vibrational relaxation of DF (v=l) by D-atoms is faster than the vibrational relaxation of HF (v= 1) by D-atoms. Room temperature vibration to translation-rotation (V ~T, R) relaxation rates in units of (/~sec Torr) -1 are as follows: 13.8• 10 -a for HF (v=l) by H, 3"1 x 10 -2 for DF (v=l) by D, 5"5x10 -3 for HF (v=l) by D, and l'9x 10 -2 for DF (v=l) by H. Rates of deactivation of vibrationally excited HF and DF molecules by H and D-atoms are very fast. Rate coefficients are provided for many reactions that have not been measured experimentally.

Analysis of nonlinear chemically reactive flow characteristic of high energy laser systems

“…In this analysis all trial functions are chosen to be linear polynomials of isoparametric coordinates. To reduce the storage requiremknts, the equations for enthalpy (9) and state (11) are incorporated in the equations of energy (8) and momentum (6, 7) respectively.…”

“…equations since the C, species equation has automatically been satisfied. The value for W, obtained from equation (30) must now be included in the energy equation, equation (9). There is also an additional radiation term to be included for the u + 1 species.…”