Journal ArticleDOI
Validation of Multitemperature Nozzle Flow Code
Chul Park,Seung-Ho Lee +1 more
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TLDR
In this paper, a computer code nozzle in n-temperatures (NOZNT) was proposed to calculate one-dimensional flows of partially dissociated and ionized air in an expanding nozzle.Abstract:
A computer code nozzle in n-temperatures (NOZNT), which calculates one-dimensional flows of partially dissociated and ionized air in an expanding nozzle, is tested against three existing sets of experimental data taken in arcjet wind tunnels. The code accounts for the differences among various temperatures, i.e., translational-rotational temperature, vibrational temperatures of individual molecular species, and electron-electronic temperature, and the effects of impurities. The experimental data considered are (1) the spectroscopic emission data; (2) electron beam data on vibrational temperature; and (3) mass-spectrometric species concentration data. It is shown that the impurities are inconsequential for the arcjet flows, and the NOZNT code is validated by numerically reproducing the experimental data.read more
Citations
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Proceedings ArticleDOI
Sensitivity Analysis of Non-equilibrium Expanding High-Enthalpy Flows
G. P. Oblapenko,Volker Hannemann +1 more
TL;DR: In this article , the role of vibrational and chemical relaxation processes on simulations of expanding hypersonic flows is considered, and the Polynomial Chaos Expansion method is used to obtain uncertainty bounds of relevant flow properties (translational and vibrational temperatures, pressure, species molar fractions), as well as their sensitivities to vibrational relaxation times and chemical reaction rates.
Proceedings ArticleDOI
Reduction of the Hypersonic Heat Flux Behavior on Catalytic Walls
TL;DR: In this article, the authors point out simple methods to take into account the wall finite catalycity when sizing the thermal protection system of a Hypersonic Re-entry Vehicle (HREV).
Journal ArticleDOI
Theoretical and numerical study of the binary scaling law for electron distribution in thermochemical non-equilibrium flows under extremely high Mach number
TL;DR: In this paper , the authors investigated the applicability of the binary scaling law in thermochemical non-equilibrium airflow and found that the failure of the scaling law is caused by three-body collision reactions and the translation-electron energy exchange from collisions between electrons and ions.
Proceedings ArticleDOI
State-to-state modeling of non-equilibrium air nozzle flows
TL;DR: In this article, one-dimensional non-equilibrium air flows in nozzles are studied on the basis of the state-to-state description of vibrational-chemical kinetics, taking into account Zeldovich exchange reactions of NO formation, dissociation, recombination and vibrational energy transitions.
Journal ArticleDOI
Computational and Experimental Study of Nonequilibrium Flow in Plasma Wind Tunnel
V. J. Unnikrishnan,Nandini Yadava,N. Virani,Joydeep Ghosh,N. Sreenivas,L. Aravindakshan Pillai,K. Bodi +6 more
TL;DR: In this paper , the Boltzmann plot method was employed to estimate the vibrational temperatures from the measured spectra, which showed that vibrational modes obey the Boltzman distribution for the conditions considered in this study.
References
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Journal ArticleDOI
Systematics of Vibrational Relaxation
TL;DR: In this article, a large number of data points for the vibrational relaxation time (pτv in atm sec) of simple systems have been logarithmically plotted vs (T°K)-⅓.
Book
Nonequilibrium hypersonic aerothermodynamics
TL;DR: In this paper, nonequilibrium phenomena in hypersonic flows are examined on the basis of theoretical models and selected experimental data, in an introduction intended for second-year graduate students of aerospace engineering.
Journal ArticleDOI
Review of chemical-kinetic problems of future NASA missions, II: Mars entries
TL;DR: A number of chemical-kinetic problems related to phenomena occurring behind a shock wave surrounding an object flying in the earth atmosphere are discussed in this paper, including the nonequilibrium thermochemical relaxation phenomena behind a wave surrounding the flying object.
Journal ArticleDOI
Vibrational Relaxation of Anharmonic Oscillators with Exchange‐Dominated Collisions
TL;DR: In this paper, an analytic expression is given for the distribution maintained by the vibration-vibration mechanism of a simple harmonic oscillator, which reduces to the usual Boltzmann-like distribution defined by a single vibrational temperature.
Book ChapterDOI
Survey of Rate Constants in the N/H/O System
Ronald K. Hanson,S. Salimian +1 more
TL;DR: A detailed survey of high-temperature N/H/O reactions and rate constants can be found in this paper, including reactions for which limited or no rate data are available currently as well as reactions which have undergone critical reviews previously or in this study.