[HTML][HTML] Adaptive coarse graining method for energy transfer and dissociation kinetics of polyatomic species

A Sahai, B Lopez, CO Johnston… - The Journal of chemical …, 2017‏ - pubs.aip.org
A novel reduced-order method is presented for modeling reacting flows characterized by
strong non-equilibrium of the internal energy level distribution of chemical species in the …

Kinetic study of low-temperature CO2 plasmas under non-equilibrium conditions. I. Relaxation of vibrational energy

T Silva, M Grofulović, BLM Klarenaar… - Plasma Sources …, 2018‏ - iopscience.iop.org
A kinetic model describing the time evolution of∼ 70 individual CO 2 (X 1 Σ+) vibrational
levels during the afterglow of a pulsed DC glow discharge is developed in order to …

Flow-radiation coupling in hypersonic wakes using reduced-order non-Boltzmann models

A Sahai, CO Johnston, B Lopez, M Panesi - Physical Review Fluids, 2019‏ - APS
The current work presents a computationally tractable simulation methodology combining
different model-reduction techniques for resolving non-Boltzmann thermodynamics …

Assessment of machine learning methods for state-to-state approach in nonequilibrium flow simulations

L Campoli, E Kustova, P Maltseva - Mathematics, 2022‏ - mdpi.com
State-to-state numerical simulations of high-speed reacting flows are the most detailed but
also often prohibitively computationally expensive. In this work, we explore the usage of …

Novel approach for CO2 state-to-state modeling and application to multidimensional entry flows

A Sahai, BE Lopez, CO Johnston… - 55th AIAA Aerospace …, 2017‏ - arc.aiaa.org
This paper presents a physics-based macroscopic model for the description of
nonequilibrium effects in CO2 flows. The starting point is the development of a vibrational …

Comparative analysis of reduced-order spectral models and grou** strategies for non-equilibrium radiation

A Sahai, CO Johnston, B Lopez, M Panesi - Journal of Quantitative …, 2020‏ - Elsevier
Radiative transfer calculations in complex three-dimensional domains are plagued by
computational bottlenecks due to the combined cost of resolving spectral, angular, and …

An Experimental Study of Thermochemical Nonequilibrium

S Gu, RG Morgan, TJ McIntyre, AM Brandis - AIAA Journal, 2022‏ - arc.aiaa.org
An experimental study of CO 2 flows subjected to expanding conditions relevant to Mars
entry is presented. A condition with a nominal velocity of 4.0 km/s was generated in the X2 …

Reduced-order modeling of non-Boltzmann thermochemistry and radiation for hypersonic flows

A Sahai - 2019‏ - ideals.illinois.edu
The non-equilibrium aerothermal environment during hypersonic flows is determined by the
interaction between a multitude of disparate physical phenomena with varying characteristic …

Refitting of detailed CO2 IR databases to vibrationally specific databases tailored for aerothermodynamic flows

JF Vargas, B Lopez, M Panesi… - … Joint Thermophysics and …, 2018‏ - arc.aiaa.org
D tabases such as CDSD or HITRAN were initially tailored for remote sensing applications,
where the transmissivity of an atm over a given spectral window has to be very precisely …

Reduced-order modeling of non-equilibrium kinetics and radiation for CO2 axisymmetric wake flows

A Sahai, B Lopez, CO Johnston… - AIP Conference …, 2019‏ - pubs.aip.org
This paper presents a physics-based reduced-order model for describing vibrational non-
equilibrium in CO2 flows. The use of the coarse grain approach, which entails grou** …