COMSOL 6.4 - Surface Dielectric Barrier Discharge

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Surface Dielectric Barrier Discharge

Surface dielectric barrier discharges (SDBDs) are a class of non-thermal plasmas generated when a high voltage is applied across electrodes separated by a dielectric material, with at least one electrode exposed to the surrounding gas. They are widely studied for applications in flow control, ozone generation, and plasma-assisted combustion.

This model simulates SDBDs using the Electric Discharge interface. The formulation captures the key physical mechanisms governing the discharge, including charge transport, impact ionization, electron attachment, recombination, and surface charge accumulation, all self-consistently coupled through the Poisson equation.

The simulation outputs include the spatial distribution of the electric field and the time-dependent number densities of electrons, positive ions, and negative ions, providing detailed insight into discharge behavior near dielectric surfaces.

Model Definition

The Electric Discharge interface is used to simulate the SDBDs. The built-in charge transport model is used:

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e, p, n denote electrons, positive ions, and negative ions

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ni is the number density of the charge carrier (SI unit: 1/m3)

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E is the electric field (SI unit: V/m)

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zi denotes the carrier charge (SI unit: 1)

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μi denotes the carrier mobility (SI unit: m2/(V·s))

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wi is the drift velocity in the electric field (SI unit: m/s)

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Di is the diffusion coefficient (SI unit: m2/s)

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Ri is the reaction rate (SI unit: 1/(m3·s))

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α is the ionization coefficient (SI unit: 1/m)

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η is the attachment coefficient (SI unit: 1/m)

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βep is the electron–ion recombination coefficient (SI unit: m3/s)

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βpn is the ion–ion recombination coefficient (SI unit: m3/s)

The above transport equations are fully coupled with Poisson’s equation through the electric field and the space charge:

where e is the elementary charge.

The Gas–Solid interface is modeled with the dedicated Dielectric Interface, Surface Transport feature described in the Electric Discharge Module User’s Guide.

Results and Discussion

Figure 1 shows the space charge density at several time instants. Figure 2 shows the isosurface plot of positive ions density along dielectric surface in 3D.

Figure 1: The distribution of space charge density at several instants.

Figure 2: The distribution of positive ions in 3D.

Electric_Discharge_Module/Dielectric_Barrier_Discharges/sdbd

Modeling Instructions

From the menu, choose .

In the window, click

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In the tree, select > .

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In the tree, select > .

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From the list, choose .

Global Definitions

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In the table, enter the following settings:


Name	Expression	Value	Description
V0	-15[kV]	-15000 V	Applied voltage
z0	50[mm]	0.05 m	Out-of-plane thickness

Rectangle 1 (r1)

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Locate the section. In the text field, type -2.

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Click to expand the section. In the table, enter the following settings:


Layer name	Thickness (mm)
Layer 1	2
Layer 2	0.5

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Electric Discharge (edis)

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Enable the isotropic diffusion stabilization.

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Add Material from Library

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Air [Kang et al. 2003] (mat1)

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Electric Discharge (edis)

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Free Triangular 1

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Step 2: Time Dependent

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Use lower of BDF solver to increase stability.

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Space Charge Density

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Solution Array 1

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Space Charge Density

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3D Plot Group 2

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