Numerical simulation of constricted and diffusive arc–anode attachments in wall-stabilized transferred argon arcs

Zhu, Tao; Wang, Hai‐Xing; Sun, Su‐Rong; Geng, Jie; Shen, Yan

doi:10.1088/2058-6272/ab4722

Cited by 11 publications

(8 citation statements)

References 72 publications

(106 reference statements)

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“…The temperature gradients of experimental data are steep, while the gradients at the same position are underestimated by the numerical model. The predicted results of the same numerical approach are also compared with the experimental results presented in [65], as shown in [40]. Generally, the results of numerical simulation predictions are acceptable in this simulation.…”

Section: Comparison and Verification Of Numerical Simulation Results ...mentioning

confidence: 81%

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Numerical simulation of the effects of protrusion on DC arc anode attachment

Niu¹,

Meng²,

Huang³

2021

Plasma Sci. Technol.

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The attachment of the DC arc on the anode is usually affected by surface morphology such as protrusions due to ablation or melting deformation. A three-dimensional thermodynamic and chemical non-equilibrium model is used to numerically simulate the effect of artificially assumed surface protrusions on the arc anode attachment. The numerical simulation results show that the arc deflects toward the protrusions on the anode and attaches to them in a constricted mode, resulting in an increase in the temperature of the arc attachment region. The analysis shows that the presence of protrusion on the anode surface changes the electric field distribution, intensifies the degree of thermodynamic and chemical non-equilibrium in its vicinity, further influences the chemical kinetic process of the plasma around it, which is the main reason for the deflection of the arc toward the protrusions and the arc anode attachment in a constricted mode. In order to verify the numerical simulation results, verification experiments are also performed using similar size scale anode protrusion, and the results showed that the presence of protrusion can indeed cause the deflection of the arc and even cause the ablation of the protrusion.

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Section: Comparison and Verification Of Numerical Simulation Results ...mentioning

confidence: 81%

“…S c,s is the chemical reaction source term which is determined by different kinetic processes shown in table 1. The diffusion flux  J s are obtained from equation (2) [40,41]. Here, p is the gas pressure.…”

Section: Main Assumptions and Governing Equationsmentioning

confidence: 99%

Numerical simulation of the effects of protrusion on DC arc anode attachment

Niu¹,

Meng²,

Huang³

2021

Plasma Sci. Technol.

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“…The plasma discharge equations, which are almost the same as in our previous papers [36][37][38], describe the species densities, electron and heavy-species temperature, the electric field, selfinduced magnetic field and velocity field in the wall-stabilized transferred arc. The governing equations used for the 3D transferred arc plasma are presented below.…”

Section: System Of Equationsmentioning

confidence: 98%

Three-dimensional chemical non-equilibrium simulation of an argon transferred arc with cross-flow

Sun

Zhu

Wang

et al. 2020

J. Phys. D: Appl. Phys.

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A three-dimensional chemical non-equilibrium plasma simulation is performed to investigate the plasma characteristics of a high-intensity argon transferred arc exposed to cross-flow. The model is validated by comparison with experimental data from the literature, and reasonable agreement is obtained for the calculated electron temperature distributions. The simulation results indicate that the interactions of the cross gas flow with the plasma column have a significant influence on the distributions of the electric field close to the anode surface. At a high cross-flow rate, corresponding changes to the distributions of current density and Joule heating occur, leading to a high electron temperature zone stretching upstream of the arc attachment region. By examining the chemical reaction processes near the anode surface, it is found that the rate of electron-impact ionization of excited atoms and the three-body recombination rate are comparable at the positions in the upstream region close to the anode surface where the electron temperature is high, so the electron density does not increase in this region. Compared to the case without cross gas flow, the heavy-species temperature distribution becomes more constricted at a large cross-flow rate, and the energy loss due to the convective cooling makes the temperature gradients steeper on the side facing the cross-flow.

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“…Previous numerous experimental studies and numerical simulations have shown that the arc may attach to the anode in a diffuse or constricted mode [8][9][10][11]. If the arc-forming gas is a molecular gas, such as the widely used nitrogen, the arc is usually attached to the anode in a constricted mode.…”

Section: Introductionmentioning

confidence: 99%

Experimental study on the effect of argon shielding gas on the suppression of nitrogen arc anode ablation

Hu¹,

Meng²,

Huang³

et al. 2022

J. Phys. D: Appl. Phys.

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The high heat flux density of the DC arc often leads to severe anode ablation, which is a key factor limiting the wider use of the DC plasma torches. In this study, a series of comparative experimental studies are conducted with the goal of suppressing nitrogen arc anode ablation by combining argon shielding flow and anode structure. It is found that for the planar electrode structure, the use of argon shielding gas can alleviate the ablation of the anode by nitrogen arc to some extent. If a boron nitride channel is installed on the anode surface to constrain the argon shielding flow, the electrode ablation can be significantly reduced. The experimental results show that there is no significant ablation on the anode surface after 1 hour of operation of the nitrogen arc device with an arc current of 100 A. Further analysis reveals that, on the one hand, argon shielding gas can extend the range of motion of the nitrogen arc root along the anode surface and increase the speed of arc root motion, which has the effect of expanding the time-averaged arc anode attachment area. On the other hand, argon shielding gas can also increase the size of the nitrogen arc root and decrease the temperature of the arc root. The use of constraining channels can effectively control the range of motion of the arc root along the anode surface and strengthen the influence of argon shielding gas. The combination of these effects can substantially suppress the anode ablation of the DC arc device.

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Numerical simulation of constricted and diffusive arc–anode attachments in wall-stabilized transferred argon arcs

Cited by 11 publications

References 72 publications

Numerical simulation of the effects of protrusion on DC arc anode attachment

Numerical simulation of the effects of protrusion on DC arc anode attachment

Three-dimensional chemical non-equilibrium simulation of an argon transferred arc with cross-flow

Experimental study on the effect of argon shielding gas on the suppression of nitrogen arc anode ablation

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