gross-et-al-2024-simulations-of-non-equilibrium-air-chemistry-compared-to-hypersonic-wind-tunnel-experiments.pdf

Simulations of Non-Equilibrium Air Chemistry Compared To

Hypersonic Wind Tunnel Experiments

T. J. Gross

∗

, E. Torres

†

and T. E. Schwartzentruber

‡

University of Minnesota, Minneapolis, MN 55455

P. M. Finch

, J. J. Girard

, T. Schwartz

‖

, Z. N. Granowitz

∗∗

, C. L. Strand

††

and R. K. Hanson

‡‡

Stanford University, Stanford, CA 94305

W. M. Yu

§§

, J. M. Austin

¶¶

and H. G. Hornung

∗∗∗

California Institute of Technology, Pasadena, CA 91125

Computational fluid dynamics simulations of hypersonic flow over a finite-span cylindrical

test article are presented and compared to laser absorption spectroscopy measurements

obtained in a high-enthalpy reflected shock tunnel. The experimental dataset consists of

simultaneous measurements of rotational temperature, vibrational temperature and mass

density of nitric oxide in the freestream and post-shock region surrounding the test article.

The partially measured freestream along with computational fluid dynamics simulations of the

shock tunnel nozzle are used to characterize the un-measured freestream properties required

to set the boundary conditions for the test article simulations. Synthetic measurements are

post-processed on the simulation results to convert simulation flow field data into a form

that is more appropriate for comparison with the experimental line of sight laser diagnostic

measurements. The computational fluid dynamics simulations use the Modified Marrone-

Treanor nonequilibrium chemical kinetics model and new vibrational relaxation time constants

for five species air that are based on quantum chemistry calculations.

I. Introduction

ultiple

experiments have been performed in the T5 Reflected Shock Tunnel [

] at the Graduate Aerospace

Laboratories at the California Institute of Technology (GALCIT) where measurements targeted the post-shock flow

surrounding multiple test articles [

]. Using tunable diode laser absorption spectroscopy (TDLAS) the experimental

team is able to infer path-averaged values of the rotational temperature, the vibrational temperature and the mass density

of nitric oxide (NO) behind the bow shock generated by these test articles. Stanford University and Caltech have also

performed a dedicated freestream measurement campaign exploring various flow conditions [

] which informed

the test article experiments. This experimental effort complements the nonequilibrium chemistry model development

being performed at the University of Minnesota. Chaudhry

et al.

[

] developed the Modified Marrone-Treanor

(MMT) nonequilibrium chemical kinetics model and subsequently implemented it into US3D [

], which is a finite

volume computational fluid dynamics (CFD) code developed by the University of Minnesota for simulating hypersonic

flows. Torres

et al.

[

] recently adapted and enhanced the chemical-kinetic dataset of the MMT model based on

the most recent potential energy surfaces (PESs) released by the Minnesota computational chemists [

]. Torres

et al.

also performed a verification study of the MMT model as implemented in US3D by comparison with direct molecular

∗

Graduate Research Assistant, Aerospace Engineering and Mechanics

†

Research Associate, Aerospace Engineering and Mechanics, AIAA member

‡

Professor of Aerospace Engineering and Mechanics, AIAA Associate Fellow

Graduate Research Assistant, Mechanical Engineering, AIAA Student Member

Ph.D, Mechanical Engineering

‖

Graduate Research Assistant, Aeronautics and Astronautics, AIAA Student Member

∗∗

Graduate Research Assistant, Mechanical Engineering

††

Senior Research Engineer, Mechanical Engineering, AIAA Member

‡‡

Clarence J. and Patricia R. Woodard Professor of Mechanical Engineering, AIAA Fellow

§§

Graduate Research Assistant, Aerospace, AIAA Student Member

¶¶

Professor of Aerospace, AIAA Associate Fellow

∗∗∗

C. L. "Kelly" Johnson Professor of Aeronautics, Emeritus, AIAA Fellow

Downloaded by 131.215.225.166 on July 3, 2024 | http://arc.aiaa.org | DOI: 10.2514/6.2024-2087

AIAA SCITECH 2024 Forum

8-12 January 2024, Orlando, FL

10.2514/6.2024-2087

J. Gross, E. Torres, T. E. Schwartzentruber, P. M. Finch, J. J. Girard, T. Schwartz, Z. N. Granowitz, C. L. Strand, R. K. Hanson, W. M. Yu, J. M. Austin, H. G. Hornung . Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.

AIAA SciTech Forum