Untitled

Pan, Wenxia; Zhang, Wenhua; Zhang, Wenhong; Wu, Chengkang

doi:10.1023/a:1007037327834

Cited by 80 publications

(47 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A DC nontransferred arc plasma torch similar to that used in [9] has been employed in the present experimental study. Pure argon is used as the plasma-forming gas, and the generated plasma jet is issued into the atmospheric-pressure air surroundings.…”

Section: Experimental Studiesmentioning

confidence: 99%

“…Indeed, long laminar plasma jets cannot be generated by use of a conventional DC arc plasma torch employed for plasma spraying [4] or even for basic studies [5,6]. However, stable long laminar thermal plasma jets have been successfully generated in recent decades by the use of specially designed DC nontransferred arc plasma torches in atmospheric-pressure air surroundings [7][8][9]. Experimental results [9,10] showed that the long laminar plasma jets are characterized by stable flow state, negligible noise emission, and reduced entrainment of ambient air into the jet, thus leading to a rather long high-temperature region length (visual jet length/diameter ratio may be as great as 80 or even more), and the jet length can be easily adjusted by changing the flow rate of the working gas or the arc current.…”

Section: Introductionmentioning

confidence: 99%

“…However, stable long laminar thermal plasma jets have been successfully generated in recent decades by the use of specially designed DC nontransferred arc plasma torches in atmospheric-pressure air surroundings [7][8][9]. Experimental results [9,10] showed that the long laminar plasma jets are characterized by stable flow state, negligible noise emission, and reduced entrainment of ambient air into the jet, thus leading to a rather long high-temperature region length (visual jet length/diameter ratio may be as great as 80 or even more), and the jet length can be easily adjusted by changing the flow rate of the working gas or the arc current. The long laminar plasma jet can be generated in a rather wide range of the working-gas flow rate and arc current of the arc plasma torch, and rather high jet inlet velocity (~1000 m/s) and temperature (~17 000 K) can be achieved.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

What do we know about long laminar plasma jets?

Chen

Pan

Meng

et al. 2006

Pure and Applied Chemistry

Self Cite

View full text Add to dashboard Cite

Silent and stable long laminar plasma jets can be generated in a rather wide range of working parameters. The laminar flow state can be maintained even if considerable parameter fluctuations exist in the laminar plasma jet or if there is an impact of laterally injected particulate matter and its carrier gas. The attractive special features of laminar plasma jets include extremely low noise level, less entrainment of ambient air, much longer and adjustable high-temperature region length, and smaller axial gradient of plasma parameters. Modeling results show that the laminar plasma jet length increases with increasing jet inlet velocity or temperature and the effect of natural convection on laminar plasma jet characteristics can be ignored, consistent with experimental observations. The large difference between laminar and turbulent plasma jet characteristics is revealed to be due to their different laws of surrounding gas entrainment. Besides the promising applications of the laminar plasma jet to remelting and cladding strengthening of the metallic surface and to thermal barrier coating preparation, it is expected that the laminar plasma jet can become a rather ideal object for the basic studies of thermal plasma science owing to the nonexistence of the complexity caused by turbulence.

show abstract

Section: Experimental Studiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

What do we know about long laminar plasma jets?

Chen

Pan

Meng

et al. 2006

Pure and Applied Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

mentioning

confidence: 99%

“…adding a piece of inter-electrode insert between the cathode and the anode [5]. Studies indicate that the long laminar plasma jets possess stable flow state, rather high flow velocity (hard or directional flow characteristic), negligible noise emission, appreciably reduced entrainment of ambient air and adjustable jet length, and thus are favorable for achieving good process reproducibility and controllability [5][6][7][8]. Preliminary attempts [7,8] to use the long laminar plasma jets in the preparation of thermal barrier coatings, in the re-melting hardening of cast iron surfaces and in the stainless-steel surface cladding have shown encouraging results, including the fine microstructure, low surface roughness and small porosity of the prepared coatings, the good re-melting process controllability and surface morphologies, as well as the preferable metallurgically bonded clad layer.…”

mentioning

confidence: 99%

Experimental Study on the Thermal Argon Plasma Generation and Jet Length Change Characteristics at Atmospheric Pressure

Pan

Meng

et al. 2006

Plasma Chem Plasma Process

Self Cite

View full text Add to dashboard Cite

The generation, jet length and flow-regime change characteristics of argon plasma issuing into ambient air have been experimentally examined. Different torch structures have been used in the tests. Laminar plasma jets can be generated within a rather wide range of working-gas flow rates, and an unsteady transitional flow state exists between the laminar and turbulent flow regimes. The high-temperature region length of the laminar plasma jet can be over an order longer than that of the turbulent plasma jet and increases with increasing argon flow rate or arc current, while the jet length of the turbulent plasma is less influenced by the generating parameters. The flow field of the plasma jet has very high radial gradients of plasma parameters, and a Reynolds number alone calculated in the ordinary manner may not adequately serve as a criterion for transition. The laminar plasma jet can have a higher velocity than that of an unsteady or turbulent jet. The long laminar plasma jet has good stiffness to withstand the impact of laterally injected cold gas and particulate matter. It could be used as a rather ideal object for fundamental studies and be applied to novel materials processing due to its attractive stable and adjustable properties.

show abstract

Production of long, laminar plasma jets at atmospheric pressure with multiple cathodes

Wang

Cui

Zhang

et al. 2017

Contributions to Plasma Physics

View full text Add to dashboard Cite

Plasma jets from conventional non-transferred arc plasma devices are usually operated in turbulent flows at atmospheric pressure. In this paper, a novel non-transferred arc plasma device with multiple cathodes is introduced to produce long, laminar plasma jets at atmospheric pressure. A pure helium atmosphere is used to produce a laminar plasma jet with a maximum length of >60 cm. The influence of gas components, arc currents, anode nozzle diameter, and gas flow rate on the jet characteristics is experimentally studied. The results reveal that the length of the plasma jet increases with increasing helium content and arc current but decreases with increasing nozzle diameter. As the gas flow rate increases, the length of the plasma jet initially increases and then decreases. Accordingly, the plasma jet is transformed from a laminar state to a transitional state and finally to a turbulent state. Furthermore, the anode arc root behaviours corresponding to different plasma jet flows are studied. In conclusion, the multiple stationary arc roots that exist on the anode just inside the nozzle entrance are favourable for the generation of a laminar plasma jet in this device. KEYWORDSanode arc root, arc plasma, jet length, laminar plasma jet, multiple cathodes 1.

show abstract

Untitled

Cited by 80 publications

References 2 publications

What do we know about long laminar plasma jets?

What do we know about long laminar plasma jets?

Experimental Study on the Thermal Argon Plasma Generation and Jet Length Change Characteristics at Atmospheric Pressure

Production of long, laminar plasma jets at atmospheric pressure with multiple cathodes

Contact Info

Product

Resources

About