TY - GEN
T1 - Development of a two-dimensional binning model for N2-N relaxation in hypersonic shock conditions
AU - Zhu, Tong
AU - Li, Zheng
AU - Levin, Deborah A.
N1 - Funding Information:
The authors would like to acknowledge Dr. van Duin for helping fitting the 3N PES using ReaxFF. The research performed at the Pennsylvania State University was supported by the Air Force Office of Scientiffic Research through the Grant No. FA9550-10-1-0563.
Publisher Copyright:
© 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All right reserved.
PY - 2016
Y1 - 2016
N2 - A high fidelity internal energy relaxation model for N2-N suitable for use in direct simulation Monte Carlo (DSMC) modeling of chemically reacting flows is proposed. A novel two-dimensional binning approach with variable bin energy resolutions in the rotational and vibrational modes is developed for treating the internal mode of N2. Both bin-to-bin and state-specific relaxation cross sections are obtained using the MD/QCT method with two potential energy surfaces as well as the state-specific database of Jaffe et al. The MD/QCT simulations of inelastic energy exchange between N2 and N also show that the VSS model is much better in capturing the forward-preferential scattering behavior in collisions at hypersonic conditions. The 99 bin model is used in homogeneous DSMC relaxation simulations and is found to be able to recover the state-specific master equation results of Panesi et al. when the Jaffe state-specific cross sections are used. Rotational relaxation energy profiles and relaxation times obtained using the ReaxFF and Jaffe PESs are in general agreement but there are larger differences between the vibrational relaxation times. These differences become smaller as the translational temperature increases because the difference in the PES energy barrier becomes less important.
AB - A high fidelity internal energy relaxation model for N2-N suitable for use in direct simulation Monte Carlo (DSMC) modeling of chemically reacting flows is proposed. A novel two-dimensional binning approach with variable bin energy resolutions in the rotational and vibrational modes is developed for treating the internal mode of N2. Both bin-to-bin and state-specific relaxation cross sections are obtained using the MD/QCT method with two potential energy surfaces as well as the state-specific database of Jaffe et al. The MD/QCT simulations of inelastic energy exchange between N2 and N also show that the VSS model is much better in capturing the forward-preferential scattering behavior in collisions at hypersonic conditions. The 99 bin model is used in homogeneous DSMC relaxation simulations and is found to be able to recover the state-specific master equation results of Panesi et al. when the Jaffe state-specific cross sections are used. Rotational relaxation energy profiles and relaxation times obtained using the ReaxFF and Jaffe PESs are in general agreement but there are larger differences between the vibrational relaxation times. These differences become smaller as the translational temperature increases because the difference in the PES energy barrier becomes less important.
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M3 - Conference contribution
AN - SCOPUS:84980401250
SN - 9781624104350
T3 - 46th AIAA Thermophysics Conference
BT - 46th AIAA Thermophysics Conference
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - 46th AIAA Thermophysics Conference, 2016
Y2 - 13 June 2016 through 17 June 2016
ER -