Capturing photoionization shadows in streamer simulations using the discrete ordinates method

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F23%3A00132994" target="_blank" >RIV/00216224:14310/23:00132994 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1088/1361-6595/acfcd8" target="_blank" >https://doi.org/10.1088/1361-6595/acfcd8</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1361-6595/acfcd8" target="_blank" >10.1088/1361-6595/acfcd8</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Capturing photoionization shadows in streamer simulations using the discrete ordinates method

Popis výsledku v původním jazyce

Numerical simulations of streamer propagation involving photoionization are presented, utilizing an ANSYS Fluent implementation that employs unstructured meshes and automatic mesh refinement. Two approximate methods for radiative transfer, used to handle computation of the photoionization source terms, are compared: the Eddington approximation and the discrete ordinates (DOs) method. The former is commonly employed in streamer simulations, while the latter is well-established in other branches of computational physics, such as radiative heat transfer. A 2D test case with two distinct regions, where streamer propagation can be triggered thanks to the protruded electrodes, is introduced. The two regions are partially separated by an opaque solid insulator barrier to study the effects of photoionization shadows on streamer inception and propagation. The primary positive streamer is initiated by placing a neutral plasma patch close to one of the electrode protrusions, while the secondary positive streamer, in the other region of the computational domain, is initiated by photoionization originating from the primary streamer zone. The Eddington approximation results in an excessively high photoionization source in the secondary streamer inception zone, as it fails to capture the shadowing effects of the opaque dielectric barrier. Consequently, this leads to a fast secondary streamer inception process, followed by rapid streamer propagation. On the other hand, the DOs method accurately captures the shadow, leading to a delayed secondary streamer inception. It is also shown that both methods exhibit very similar results when the dielectric barrier is transparent and the shadow is absent. This work demonstrates that using the DOs method for streamer simulations offers considerable advantages over the Eddington approximation, especially in cases involving more complex geometries where shadows need to be captured for accurate streamer inception and dynamics.

Název v anglickém jazyce

Capturing photoionization shadows in streamer simulations using the discrete ordinates method

Popis výsledku anglicky

Numerical simulations of streamer propagation involving photoionization are presented, utilizing an ANSYS Fluent implementation that employs unstructured meshes and automatic mesh refinement. Two approximate methods for radiative transfer, used to handle computation of the photoionization source terms, are compared: the Eddington approximation and the discrete ordinates (DOs) method. The former is commonly employed in streamer simulations, while the latter is well-established in other branches of computational physics, such as radiative heat transfer. A 2D test case with two distinct regions, where streamer propagation can be triggered thanks to the protruded electrodes, is introduced. The two regions are partially separated by an opaque solid insulator barrier to study the effects of photoionization shadows on streamer inception and propagation. The primary positive streamer is initiated by placing a neutral plasma patch close to one of the electrode protrusions, while the secondary positive streamer, in the other region of the computational domain, is initiated by photoionization originating from the primary streamer zone. The Eddington approximation results in an excessively high photoionization source in the secondary streamer inception zone, as it fails to capture the shadowing effects of the opaque dielectric barrier. Consequently, this leads to a fast secondary streamer inception process, followed by rapid streamer propagation. On the other hand, the DOs method accurately captures the shadow, leading to a delayed secondary streamer inception. It is also shown that both methods exhibit very similar results when the dielectric barrier is transparent and the shadow is absent. This work demonstrates that using the DOs method for streamer simulations offers considerable advantages over the Eddington approximation, especially in cases involving more complex geometries where shadows need to be captured for accurate streamer inception and dynamics.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

<a href="/cs/project/TK04020069" target="_blank" >TK04020069: Streamery a klouzavé výboje na površích izolantů v alternativních plynech k SF6</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Plasma Sources Science and Technology

ISSN

0963-0252

e-ISSN

1361-6595

Svazek periodika

32

Číslo periodika v rámci svazku

10

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

12

Strana od-do

1-12

Kód UT WoS článku

001081544200001

EID výsledku v databázi Scopus

2-s2.0-85175658880