@article{fd766498ab864515b915278af4d55d3e,
title = "Collisional Radiative Modeling of Electronically Excited States in a Hypersonic Flow",
abstract = "The hypersonic, nonequilibrium thermochemistry flow over a cylinder was modeled to study nitric oxide (NO) ultraviolet (UV) emissions. The main focus of this work is to model the populations of the electronically excited states of N2 and NO because the transitions from those states to ground states are responsible for UV emissions. Collisional radiative models were constructed for the purpose of predicting the electronically excited state populations using two approaches, the quasi-steady-state (QSS) method and a MassTR method. These methods were applied to flows generated by the direct simulation Monte Carlo method of ground state species for two types of collisional radiative models. The results showed that when the coupling between the formation of electronically excited states and flow transport was modeled, this resulted in higher populations of the electronically excited states of N2 (A3Σu) and NO in the expansion and wake regions of the flow compared to the QSS result where flow transport is not included. In addition, it was shown that the N2 (A3Σu ) state is responsible for the most of the NO(A) state population downstream of the stagnation region.",
author = "Karpuzcu, {Irmak T.} and Jouffray, {Matthew P.} and Levin, {Deborah A.}",
note = "The research being performed at the University of Illinois Urbana-Champaign is supported by the Air Force Office of Scientific Research (AFOSR) through AFOSR Grant No. FA9550-19-1-0342. Computational resources for this research are provided by the Texas Advanced Computing Center{\textquoteright}s (TACC) Stampede2 super-computer with the project number TGATM200010. TACC is a part of National Science Foundation{\textquoteright}s (NSF) The Extreme Science and Engineering Discovery Environment (XSEDE) project. The authors would also like to thank Ingrid Wysong and Sergey Gimelshein for useful discussions about the direct simulation Monte Carlo setup and results, as well as Ozgur Tumuklu and Thong Zu for their help with the collisional-radiative model. The research being performed at the University of Illinois Urbana-Champaign is supported by the Air Force Office of Scientific Research (AFOSR) through AFOSR Grant No. FA9550-19-1-0342. Computational resources for this research are provided by the Texas Advanced Computing Center{\textquoteright}s (TACC) Stampede2 supercomputer with the project number TGATM200010. TACC is a part of National Science Foundation{\textquoteright}s (NSF) The Extreme Science and Engineering Discovery Environment (XSEDE) project. The authors would also like to thank Ingrid Wysong and Sergey Gimelshein for useful discussions about the direct simulation Monte Carlo setup and results, as well as Ozgur Tumuklu and Thong Zu for their help with the collisional-radiative model. †Graduate Student, Department of Aerospace Engineering, GAANN Fellowship from the U.S. Dept. of Education. ‡Professor, Department of Aerospace Engineering. Fellow AIAA.",
year = "2022",
month = oct,
doi = "10.2514/1.T6505",
language = "English (US)",
volume = "36",
pages = "982--1002",
journal = "Journal of thermophysics and heat transfer",
issn = "0887-8722",
publisher = "AIAA International",
number = "4",
}