Numerical Analysis of Rarefied Gas Flows Using the Academic CFD Code Galatea

Klothakis, Angelos; Lygidakis, Georgios N.; Nikolos, Ioannis K.

doi:10.7712/100016.1863.5044

Cited by 3 publications

(2 citation statements)

References 37 publications

(103 reference statements)

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“…The DSMC method is a particle-based simulation technique that serves as a stochastic solver for the Boltzmann equation [76]. This accurately describes the behavior of particles across all flow regimes [77][78][79]. The DSMC framework is adopted and revised from the SPARTA code [80].…”

Section: Hybrid Pic-dsmc Methodsmentioning

confidence: 99%

Plasma plume simulation of an atomic oxygen-fed ion thruster in very-low-earth-orbit

Moon,

Choe,

Jun

2023

Plasma Sources Sci. Technol.

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The plasma plume flow of an atomic oxygen-fed (AO-fed) ion thruster is numerically investigated as a simplification of the atmosphere-breathing electric propulsion (ABEP). A predictive analysis is conducted focusing on the ion backflow phenomenon and plume-background interaction in very-low-earth-orbit (VLEO). The computational framework employs two sequentially integrated numerical methods: a zero-dimensional (0-D) analytical model for the radio-frequency ion thruster and a hybrid method of the particle-in-cell (PIC) and direct simulation Monte Carlo (DSMC) techniques. The 0-D analytic model is employed for the prediction of exhaust conditions, while the hybrid PIC-DSMC method adopts these predictions to conduct the plasma plume simulations. A generalized collision cross-section model is introduced to enable consistent kinetic simulations for both AO and xenon propellants in VLEO atmosphere. The plasma plume simulations are conducted in an axisymmetric domain, including a cylindrical satellite body to consider wake flow. The exhaust ions exhibit diffusive transport transverse to the ion beam direction, implying the ion backflow. The backflowing ion current density can be increased in AO-fed thrusters, which require a high propellant flow rate to achieve a practical thrust. The AO-fed ion thruster shows a more active interaction between its plasma plume and the VLEO atmosphere compared to conventional xenon-based thrusters. The intensified plume-background interaction modifies the backflowing ion current density and the kinetic energy of individual ions, factors related to the spacecraft’s surface contamination.

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Section: Hybrid Pic-dsmc Methodsmentioning

confidence: 99%

Plasma plume simulation of an atomic oxygen-fed ion thruster in very-low-earth-orbit

Moon,

Choe,

Jun

2023

Plasma Sources Sci. Technol.

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“…The majority of the existing DSMC codes (academic or commercial) have to be coupled with a mesh generator to provide them with a discretized geometry. Examples of such codes are DAC [2], SMILE [3], MONACO [4], SPARTA [5], MGDS [6], as well as dsmcFoam [7].…”

Section: Introductionmentioning

confidence: 99%

An improved combinatorial geometry model for arbitrary geometry in DSMC

Kargaran¹,

Minuchehr²,

Zolfaghari³

2017

J. Stat. Mech.

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This paper focuses on a new direct simulation Monte Carlo (DSMC) code based on combinatorial geometry (CG) for simulation of any rarefied gas flow. The developed code, called DgSMC-A, has been supplied with an improved CG modeling able to significantly optimize the particle-tracking process, resulting in a highly reduced runtime compared to the conventional codes. The improved algorithm inserts a grid over the geometry and saves those grid elements containing some part of the geometry border. Since only a small part of a grid is engaged with the geometry border, significant time can be saved using the proposed algorithm. Embedding the modified algorithm in the DgSMC-A resulted in a fast, robust and self-governing code needless to any mesh generator. The code completely handles complex geometries created with first-and second-order surfaces. In addition, we developed a new surface area calculator in the CG methodology for complex geometries based on the Monte Carlo method with acceptable accuracy. Several well-known test cases are examined to indicate the code ability to deal with a wide range of realistic problems. Results are also found to be in good agreement with references and experimental data.

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