A new nitrogen dissociation model for direct simulation Monte Carlo (DSMC) is formulated based on reaction cross-sections obtained from quasi-classical-trajectory (QCT) calculations using an ab initio potential energy surface (PES). The proposed model accurately captures the dependence of different molecular energies on the dissociation process, such as favoring due to vibrational and rotational energy. The probability model is then averaged over all molecular energies in the near-equilibrium limit to obtain a dissociation rate coefficient expression, suitable for use in computational fluid dynamics (CFD) calculations. The proposed CFD dissociation model is dependent on average translational, rotational, and vibrational energies and is shown to reproduce nonequilibrium rates, where the average internal energy is not in equilibrium with the average translational energy. An advantage of the proposed models is that they are analytically consistent and therefore could be useful for hybrid DSMC-CFD simulations of hypersonic flows.
|Original language||English (US)|
|Title of host publication||47th AIAA Thermophysics Conference, 2017|
|Publisher||American Institute of Aeronautics and Astronautics Inc, AIAA|
|State||Published - 2017|
|Event||47th AIAA Thermophysics Conference, 2017 - Denver, United States|
Duration: Jun 5 2017 → Jun 9 2017
|Name||47th AIAA Thermophysics Conference, 2017|
|Other||47th AIAA Thermophysics Conference, 2017|
|Period||6/5/17 → 6/9/17|
Bibliographical noteFunding Information:
The research presented is supported by Air Force Office of Scientific Research (AFOSR) under Grant No. FA9550-16-1-0161. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the AFOSR or the US government. The research is also partially supported by the Air Force Research Laboratory (AFRL) under grant FA9453-17-1-0101.
© 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.