Three-Temperature Model Applied to Thermochemical Non-Equilibrium Reentry Flows in 2D—Seven Species

Edisson Sávio De Góes Maciel

doi:10.4236/ojfd.2022.121001

Abstract

In this work, a study involving the fully coupled Euler and Navier-Stokes reactive equations is performed. These equations, in conservative and finite volume contexts, employing structured spatial discretization, on a condition of thermochemical non-equilibrium, are analyzed. High-order studies are accomplished using the Spectral method of Streett, Zang, and Hussaini. The high enthalpy hypersonic flows around a circumference, around a reentry capsule, along a blunt body, and along a double ellipse in two-dimensions are simulated. The Van Leer, Liou and Steffen Jr., and Steger and Warming flux vector splitting algorithms are applied to execute the numerical experiments. Three temperatures, which are the translational-rotational temperature, the vibrational temperature, and the electron temperature, are used to accomplish the numerical comparisons. Excellent results were obtained with minimum errors inferior to 6.0%. The key contribution of this work is the correct implementation of a three temperature model coupled with the implementation of three algorithms to perform the numerical simulations, as well the description of energy exchange mechanisms to perform more realistic simulations.

Highlights

Several conceptual designs for vehicles that would fly in the atmosphere at hypersonic speeds have been developed recently [1]
The key contribution of this work is the correct implementation of a three temperature model coupled with the implementation of three algorithms to perform the numerical simulations, as well the description of energy exchange mechanisms to perform more realistic simulations
The accuracy of macroscopic temperature models, such as the Landau-Teller translation-vibration (T-V) model, can lead to questioning of the underlying approximations. Such questioning in the past invariably has lead to the development of gas kinetic schemes, such as the Bhatnagar-Gross-Krook scheme [3], to describe the energy exchanges

Summary

Introduction

Several conceptual designs for vehicles that would fly in the atmosphere at hypersonic speeds have been developed recently [1]. The air that envelops these vehicles is chemically reacted, vibrationally excited, and ionized The motivation for multi-temperature model studies often originates for ionized flows owing to the wide disparities in the masses of the constituent species [2]. In this regard, the accuracy of macroscopic temperature models, such as the Landau-Teller translation-vibration (T-V) model, can lead to questioning of the underlying approximations. The subjective question of the effect of the various energy exchanges using approximate macroscopic temperature models on the shock structure of hypersonic flows can be answered with greater ease if the analysis is made for flows within the continuum regime

Objectives

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Results

Conclusion