Experimental investigation of the anode region of a free-burning atmospheric-pressure inert-gas arc. II. Intermediate current regime—multiple anode constriction

1997 ◽  
Vol 42 (1) ◽  
pp. 35-38 ◽  
Author(s):  
F. G. Baksht ◽  
G. A. Dyuzhev ◽  
N. K. Mitrofanov ◽  
S. M. Shkol’nik
Keyword(s):  
Experimental Investigation ◽  
Atmospheric Pressure ◽  
Inert Gas ◽  
Anode Region ◽  
Current Regime

The Influence of Radiation on Arc Constriction in the Anode Region

1975 ◽  
Vol 97 (1) ◽  
pp. 41-46 ◽  
Author(s):  
E. Pfender ◽  
J. Schafer
Keyword(s):  
Analytical Model ◽  
Atmospheric Pressure ◽  
High Intensity ◽  
Radiation Effects ◽  
Relaxation Method ◽  
Anode Region ◽  
Conservation Equations ◽  
Radiation Losses ◽  
Argon Arcs

An improved analytical model for the description of the anode contraction zone of a high intensity arc takes radiation effects into account. The conservation equations for the anode contraction zone and the adjacent undisturbed arc column are solved numerically with a relaxation method. Results for atmospheric pressure argon arcs at three different currents demonstrate that radiation losses reduce temperature peaks substantially and, at the same time, provide a smooth matching of arc column and contraction zone solutions. Although the model seems to be adequate for a large portion of the anode contraction zone, the results indicate that refinements of the model are necessary for the region close to the anode, in particular, deviations from LTE have to be taken into account.

scholarly journals Влияние предыонизации на микроканальную структуру искрового разряда в воздухе в промежутке острие-плоскость

2022 ◽  
Vol 92 (1) ◽  
pp. 52
Author(s):  
А.А. Тренькин ◽  
К.И. Алмазова ◽  
А.Н. Белоногов ◽  
В.В. Боровков ◽  
Е.В. Горелов ◽  
...  
Keyword(s):  
Wave Front ◽  
Electron Concentration ◽  
Atmospheric Pressure ◽  
Initial Phase ◽  
Discharge Channel ◽  
Cathode Region ◽  
Ionization Wave ◽  
Anode Region ◽  
Microstructure Formation ◽  
Micron Diameter

The initial phase of a spark discharge in the gap between the pin (cathode) and a plane 1.5 mm long in atmospheric pressure air under conditions of preliminary photoionization by an auxiliary discharge was investigated by the method of shadow photography. In the absence of preionization, the discharge from the first nanoseconds after breakdown is an aggregate of a large number of micron-diameter channels. It was found that the electron concentration resulting from preionization, estimated at 108  109 cm-3, increases the degree of uniformity of the discharge channel in the near-cathode region; however, in the near-anode region, the channel remains microstructured. Within the framework of the mechanism of microstructure formation due to the instability of the ionization wave front, a criterion for the formation of a uniform discharge is obtained and an explanation of the results obtained is presented.

Heat Transfer in Film Boiling With Pulsating Pressures

1964 ◽  
Vol 86 (3) ◽  
pp. 457-460 ◽  
Author(s):  
D. A. Di Cicco ◽  
R. J. Schoenhals
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Heat Transfer Rate ◽  
High Purity ◽  
Atmospheric Pressure ◽  
Transfer Rate ◽  
Peak Pressure ◽  
Film Boiling ◽  
Periodic Pressure ◽  
Initial Results

The purpose of this exploratory experimental investigation was to determine the effect on the heat-transfer rate when a pulsating pressure is applied to a stable film boiling system. The test section used consisted of a 0.030-in-dia horizontal platinum wire. The boiling medium was monofluorotrichloromethane, C Cl3F, commercially available in high purity as Refrigerant 11. A boiling curve was obtained at atmospheric pressure. In addition, pulsating tests were conducted for various pulsing rates and for three different test wire temperatures. Periodic pressure pulses of approximately 100 psi were applied to the system. The initial results thus far obtained in this investigation show a substantial increase in the heat-transfer rate for pulsing frequencies ranging from 11.3 cps to 25.8 cps. The improvement is noted to be from 59.5 percent to 103 percent above the heat-transfer rate for film boiling at atmospheric pressure at the same temperature difference between the test wire and the fluid. It was also found that the heat-transfer rate achieved was higher than the average of the heat-transfer rate for atmospheric pressure film boiling and that for subcooled film boiling at the peak pressure achieved in pulsing. For the higher pulsing frequencies, the heat-transfer rate was found to be even greater than that for subcooled film boiling at the peak pressure.

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