Advanced Validation of Nonequilibrium Plasma Flow Simulation for Arc-Heated Wind Tunnels

Takahashi, Yusuke; Abe, Takashi; Takayanagi, Hideaki; Mizuno, Masahito; Kihara, Hisashi; Abe, Ken

doi:10.2514/1.t3991

Cited by 8 publications

(7 citation statements)

References 41 publications

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“…The high pressures encountered in the arc-heater facility result in a large number of collisions and rapid thermal equilibration. Similar findings have been reported in previous studies focusing on the flow-field inside large arc-heated wind tunnels [5,11]. Consequently, T ev and T are expected to be in equilibrium in the majority of the flowfield.…”

Section: Mathematical Model: Non-equilibrium Plasma Flowssupporting

confidence: 90%

“…Similar analyses have been performed on the Kyushu University Wind Tunnel and on a larger arc heater in JAXA [7]. The main objective was to examine the impact of turbulent and radiative heat transfer on the flow-field for facilities of different sizes [8][9][10][11]. Trelles et al [12][13][14][15] have worked extensively on finite element modeling of industrially-relevant argon based arc plasma torches while employing simple empirical radiation models.…”

Section: Introductionmentioning

confidence: 99%

“…There are different studies on the use of finite element discretization to solve the magneto-hydrodynamics equations [41,42] which allow for the interaction between electromagnetic forces and the underlying flowfield to be resolved acccurately. The current analysis follows the approach adopted by researchers investigating the AHF and large arc-heated wind tunnels in general [5,11] and introduces certain simplifications to the treatment of the EM field. The external and self-induced magnetic fields are neglected and electric discharge is modeled assuming a static electric field.…”

Section: Introductionmentioning

confidence: 99%

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Modeling of high pressure arc-discharge with a fully-implicit Navier–Stokes stabilized finite element flow solver

Sahai

Mansour

López

et al. 2017

Plasma Sources Sci. Technol.

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This work addresses the modeling of high pressure electric discharge in an arc-heated wind tunnel. The combined numerical solution of Poisson's equation, radiative transfer equations, and the set of Favre-averaged thermochemical nonequilibrium Navier-Stokes equations allows for the determination of the electric, radiation, and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles with the Chapman-Enskog method. A multi-temperature formulation is used to account for thermal non-equilibrium. Finally, the turbulence closure of the flow equations is obtained by means of the Spalart-Allmaras model, which requires the solution of an additional scalar transport equation. A Streamline upwind Petrov-Galerkin stabilized finite element formulation is employed to solve the Navier-Stokes equation. The electric field equation is solved using the standard Galerkin formulation. A stable formulation for the radiative transfer equations is obtained using the least-squares finite element method. The developed simulation framework has been applied to investigate turbulent plasma flows in the 20 MW Aerodynamic Heating Facility at NASA Ames Research Center. The current model is able to predict the process of energy addition and re-distribution due to Joule heating and thermal radiation, resulting in a hot central core surrounded by colder flow. The use of an unsteady three-dimensional treatment also allows the asymmetry due to a dynamic electric arc attachment point in the cathode chamber to be captured accurately. The current work paves the way for detailed estimation of operating characteristics for arc-heated wind tunnels which are critical in testing thermal protection systems.

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Section: Mathematical Model: Non-equilibrium Plasma Flowssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling of high pressure arc-discharge with a fully-implicit Navier–Stokes stabilized finite element flow solver

Sahai

Mansour

López

et al. 2017

Plasma Sources Sci. Technol.

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show abstract

“…The spectroscopic analysis of the molecular band, [8], laserinduced fluorescence (LIF) [9,10], and cavity-enhanced absorption spectroscopy [11], which are non-intrusive techniques, have been used to identify arc-heated flow properties. The emission spectra of the arc column in a constrictor revealed the distributions of translational temperature, flow velocity, and electron number density in the heating section [12,13]. Zander et al [14] directly measured the translational temperature and velocity of a plasma flow using the Fabry-Perot spectroscopic technique.…”

Section: Introductionmentioning

confidence: 99%

Flow Enthalpy of Nonequilibrium Plasma in 1 MW Arc-Heated Wind Tunnel

Takahashi¹,

Enoki²,

Koike³

et al. 2021

AIAA Journal

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The flow enthalpy of an arc-heated wind tunnel is an important parameter for reproducing planetary entry and performing heating tests. However, its distribution is insufficiently clarified owing to complicated phenomena, such as arc discharge and supersonic expansion. In this study, we assess the enthalpy of an arc-heated flow in a large-scale facility based on measurements and computational results. The flow enthalpy of high-temperature gases, which comprised thermal, chemical, kinetic, and pressure components, was reconstructed based on the measured rotational temperature, heat flux, and impact pressure, in addition to the computational science approach. The rotational temperature of nitric oxide molecules was obtained using emission spectroscopic measurements of band spectra in the near-ultraviolet range. A numerical model was developed and validated based on measured data. The results indicated that the model efficiently reproduced the arc discharge behavior in the heating section and the thermochemical non-equilibrium in the expansion section. It was discovered that the dominant components of the arc-heated flow in the test section were the chemical and kinetic components. The flow enthalpy exhibited a non-uniform distribution in the radial direction. We conclude that the flow enthalpy of the core is approximately 28 MJ/kg at the nozzle exit.

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“…Emission spectroscopy [10], laser-induced fluorescence (LIF) [11,12], and cavityenhanced absorption spectroscopy [13] have been used to investigate such flows. In some studies, spectroscopic measurements of heated areas have been performed [14,15]. Zander et al [16] used the Fabry-Perot spectroscopic technique to measure the translational temperature and velocity.…”

Section: Introductionmentioning

confidence: 99%

Nonequilibrium shock layer in large-scale arc-heated wind tunnel

Takahashi¹,

Takasawa²,

Yamada³

et al. 2022

J. Phys. D: Appl. Phys.

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An arc-heated wind tunnel is one of the most important facilities to reproduce the high-temperature environment during atmospheric entry for plasma studies and spacecraft development. However, the properties of the plasma flow cannot be determined easily, because of the complex physical phenomena, such as arc discharge and supersonic expansion, occurring inside the tunnel. The shock-layer structure should be clarified to evaluate the aerodynamic characteristics, communication conditions, and thermal- protection performance in a high-temperature environment. In this study, shock-layer spectroscopic measurements of a plasma flow in a 1 MW-class arc-heated wind tunnel were performed. The γ-band system spectra of nitric oxide (NO) molecules in the ultraviolet region were measured, and the rotational temperature was determined via spectral fitting through comparison with numerical spectra. The rotational temperature of the NO molecules in the shock layer was 6,620±350 K, whereas that in the free jet was much lower at 770±60 K. This difference is attributed to the increase in translational temperature by flow stagnation across the shock wave, followed by the increase in rotational temperature owing to energy relaxation. A computational science approach revealed the detailed structure of the flow through comparisons with the spectroscopic measurement data. The wind tunnel flow became hypersonic with high temperature and low pressure due to the expansion and acceleration at the nozzle and test chamber. Although the temperature increased across the shock wave, the chemical reaction progressed slowly owing to the low-pressure environment. The rotational temperature in the shock layer increased with the translational temperature; this agrees with the trend of the measurement results. The arc-heated flow was found to be in strong thermo- chemical nonequilibrium in the shock layer. Through this study, a detailed structure of arc-heated flow was revealed and its methodology was also proposed.

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Advanced Validation of Nonequilibrium Plasma Flow Simulation for Arc-Heated Wind Tunnels

Cited by 8 publications

References 41 publications

Modeling of high pressure arc-discharge with a fully-implicit Navier–Stokes stabilized finite element flow solver

Modeling of high pressure arc-discharge with a fully-implicit Navier–Stokes stabilized finite element flow solver

Flow Enthalpy of Nonequilibrium Plasma in 1 MW Arc-Heated Wind Tunnel

Nonequilibrium shock layer in large-scale arc-heated wind tunnel

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