scholarly journals Stability, spatial extension and extinction of an electric arc in aeronautical conditions of pressure under 540 V DC

2019 ◽  
Vol 87 (3) ◽  
pp. 30901
Author(s):  
Romaric Landfried ◽  
Mohamed Boukhlifa ◽  
Thierry Leblanc ◽  
Philippe Teste ◽  
Jonathan Andrea
Keyword(s):  
High Speed ◽  
Electric Arc ◽  
High Speed Camera ◽  
Arc Length ◽  
Electrode Gap ◽  
Arc Current ◽  
The Mean ◽  
The Stability ◽  
Energy Dissipated

This work deals with the characterization of DC electric arcs in aeronautical conditions of pressure (from 104 Pa to 105 Pa). Observations have been made with the help of a high speed camera and various characteristics of electric arc under 540 V DC have been studied: the stability arc length, the extinction gap, the arc duration and the mean energy dissipated in the arc. The arc current intensity range is 10–100 A. The obtained results show that the arc stability length, extinction electrode gap, arc duration and energy dissipation in the arc have a direct correlation with the pressure and the current in the circuit.

Study on Arc and Drop Transfer Behaviors of DCEN MAG Welding

2014 ◽  
Vol 887-888 ◽  
pp. 1290-1293
Author(s):  
Xu Ming Wang ◽  
Qing Xia Bi
Keyword(s):  
Direct Current ◽  
High Speed ◽  
Welding Process ◽  
Mag Welding ◽  
High Speed Camera ◽  
High Current ◽  
Current Electrode ◽  
The Stability

By means of the high speed camera, the arc and drop transfer behaviours of direct current electrode negative MAG welding process are researched. The influences of luminous arc ball on the stability of MAG welding process are analyzed. On this basis, the process interval of DCEN MAG welding is determined. And the influences of wire polarity on wire melting coefficient are compared. By using the shield gas 98%Ar + 2%O2, the stable drop transfer manner can be divided into two kinds: dropwise transfer with low current, and streaming transfer with high current.

scholarly journals 3D Analysis of Low-Voltage Gas-Filled DC Switch Using Simplified Arc Model

2019 ◽  
Vol 6 (1) ◽  
pp. 65-68 ◽  
Author(s):  
S. Gortschakow ◽  
D. Gonzalez ◽  
S. Yu ◽  
F. Werner
Keyword(s):  
High Speed ◽  
Low Voltage ◽  
Black Box ◽  
Optical Observations ◽  
3D Analysis ◽  
High Speed Camera ◽  
Plasma Model ◽  
Arc Model ◽  
Arc Current ◽  
Electro Magnetic

Electro-magnetic simulations have been used for the visualization of distribution of Lorentz force acting on a DC switching arc in low-voltage contactor. A simplified plasma model (black-box model) was applied for the description of arc conductivity. Arc geometry was gained from the high-speed camera images. Influence of arc position, arc current and of external magnetic field has been studied. Results have been compared with optical observations of the arc dynamics.

scholarly journals Effect of External Magnetic Field on Long DC Arc Characteristics with Rng-shaped Anode

2021 ◽  
Vol 333 ◽  
pp. 03004
Author(s):  
Akio Hashizawa ◽  
Manabu Tanaka ◽  
Takayuki Watanabe ◽  
Tomohiro Koga
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
High Speed ◽  
Plasma Jet ◽  
Jet Flow ◽  
Critical Issue ◽  
Fluctuation Phenomena ◽  
High Speed Camera ◽  
Electrode Gap ◽  
Dc Arc

Fluctuation phenomena of plasma jet flow in an innovative long DC arc system with a ring-shaped anode were successfully clarified by a high-speed camera visualization. The long DC arc with long electrode gap distance more than 350 mm has been applied to gas decomposition due to its advantages of long plasma length, resulting in long residence time of treated gas. However, large heat loss at a conventional hemispherical-shaped anode was a critical issue in the long DC arc system. Therefore, the ring-shaped anode was utilized to convert large energy loss at the anode into the plasma jet flow. High-speed camera observation revealed the effect of external magnetic field on the fluctuation phenomena. Plasma jet fluctuates with the frequency of several tens Hz when the magnetic field was applied. These understanding of arc and plasma jet fluctuation enables to improve the capability of long DC arc system.

Dynamic Impact Characterization of Al+Fe2O3+30% Epoxy Composites Using Time Synchronized High-Speed Camera and VISAR Measurements

2005 ◽  
Vol 896 ◽  
Author(s):  
Louis Ferranti ◽  
Naresh N. Thadhani
Keyword(s):  
Dynamic Loading ◽  
High Speed ◽  
Elastic Recovery ◽  
Axial Strain ◽  
Epoxy Composites ◽  
Surface Velocity ◽  
High Speed Camera ◽  
Wave Interactions ◽  
Impact Experiments

AbstractReverse Taylor anvil-on-rod impact experiments were conducted on Al+Fe2O3+30% epoxy composites to measure their viscoelastic and fracture response to dynamic loading. Impact velocities ranged from 80 to 200 m/s. High-speed camera images capturing transient deformation reveal these materials exhibit significant elastic recovery in both the longitudinal and radial directions. Images were time synchronized with free surface velocity measurements, using VISAR, to track elastic/plastic wave interactions attributed to the material’s dynamic loading response. Some specimens underwent brittle fracture once a critical areal strain was exceeded while the axial strain response appeared unaltered.

scholarly journals High-speed camera characterization of voluntary eye blinking kinematics

2013 ◽  
Vol 10 (85) ◽  
pp. 20130227 ◽  
Author(s):  
Kyung-Ah Kwon ◽  
Rebecca J. Shipley ◽  
Mohan Edirisinghe ◽  
Daniel G. Ezra ◽  
Geoff Rose ◽  
...  
Keyword(s):  
Clinical Research ◽  
Healthy Volunteers ◽  
Ocular Surface ◽  
High Speed ◽  
High Potential ◽  
Potential Usefulness ◽  
High Speed Camera ◽  
Master Curves ◽  
Time Data

Blinking is vital to maintain the integrity of the ocular surface and its characteristics such as blink duration and speed can vary significantly, depending on the health of the eyes. The blink is so rapid that special techniques are required to characterize it. In this study, a high-speed camera was used to record and characterize voluntary blinking. The blinking motion of 25 healthy volunteers was recorded at 600 frames per second. Master curves for the palpebral aperture and blinking speed were constructed using palpebral aperture versus time data taken from the high-speed camera recordings, which show that one blink can be divided into four phases; closing, closed, early opening and late opening. Analysis of data from the high-speed camera images was used to calculate the palpebral aperture, peak blinking speed, average blinking speed and duration of voluntary blinking and compare it with data generated by other methods previously used to evaluate voluntary blinking. The advantages of the high-speed camera method over the others are discussed, thereby supporting the high potential usefulness of the method in clinical research.

Characterization of calculus migration during Ho:YAG laser lithotripsy by high speed camera using suspended pendulum method

2014 ◽  
Author(s):  
Jian James Zhang ◽  
Danop Rajabhandharaks ◽  
Jason Rongwei Xuan ◽  
Ray W. J. Chia ◽  
Tom Hasenberg
Keyword(s):  
High Speed ◽  
Laser Lithotripsy ◽  
High Speed Camera ◽  
Ho:Yag Laser

scholarly journals Reliability of the High-speed Camera-based System (HSC-Kinovea) for lower-limb explosive strength endurance assessment in athletes

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Carlos Gilberto Freitas-Junior ◽  
Pedro Pinheiro Paes ◽  
Leonardo Sousa Fortes ◽  
Alessandro José Da Silva ◽  
Manoel Cunha Costa ◽  
...  
Keyword(s):  
Lower Limb ◽  
High Speed ◽  
Average Power ◽  
High Speed Camera ◽  
Mean Power ◽  
Explosive Strength ◽  
Vertical Jumping ◽  
Jumping Test ◽  
The Mean ◽  
Typical Measurement

The present study verified the reliability of the high-speed camera-based system (HSC-Kinovea) in the lower-limb explosive strength endurance assessment in athletes. Eleven male volleyball players (21.8 ± 2.9 years; 186.3 ± 6.2 cm and 82.3 ± 11.0 kg) participated in the intermittent vertical jumping test in two days. The test was filmed and later analyzed using Kinovea 0.8.15 software to obtain the mean and peak power variables. Regarding reliability, the intra-class correlation coefficient, the typical error of measurements, and Bland-Altman plots were used. The method presented satisfactory values for inter and intra-class correlations (˃ 0.88). The typical values error of measurement presented in the inter-rater analysis was 0.95 W.kg-1 and 0.59 W.kg-1 for the peak and the mean power, respectively. In the intra-assessment analyses, the typical measurement error values were 7.02 W.kg-1 and 5.66 W.kg-1 (test-retest) and 1.59 W.kg-1 and 0.24 W.kg-1  (duplicates videos) for peak and average power, respectively. The HSC-Kinovea system is reliable for assessing the variables of the explosive strength endurance in athletes.

scholarly journals Characterization of a nitrogen gliding arc plasmatron using optical emission spectroscopy and high-speed camera

2018 ◽  
Vol 52 (6) ◽  
pp. 065201 ◽  
Author(s):  
Sven Gröger ◽  
Marleen Ramakers ◽  
Marc Hamme ◽  
Jose A Medrano ◽  
Nikita Bibinov ◽  
...  
Keyword(s):  
Emission Spectroscopy ◽  
High Speed ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
High Speed Camera ◽  
Gliding Arc

Design of a test rig for fundamental investigations of spark characteristics

2019 ◽  
Vol 21 (8) ◽  
pp. 1412-1425 ◽  
Author(s):  
Anton Tilz ◽  
Georg Meyer ◽  
Constantin Kiesling ◽  
Gerhard Pirker ◽  
Sebastian Salbrechter ◽  
...  
Keyword(s):  
Flow Velocity ◽  
High Speed ◽  
Electric Arc ◽  
Combustion Stability ◽  
Arc Length ◽  
Test Rig ◽  
Arc Behavior ◽  
Cycle Variation ◽  
Spark Plug ◽  
Flow Velocities

A common means to increase efficiency in stationary spark ignited engines is to operate the engine with a higher air/fuel ratio of the mixture in conjunction with a higher turbulence level; however, this generally leads to severe conditions that significantly impact the inflammability of the gas–air mixture and combustion stability. Because the electric arc that forms at the spark plug is a main influencing factor in combustion, detailed research work in the field of electric arc behavior generated at spark plugs is required. This article thus presents a specially tailored test rig that is designed to facilitate an investigation of electric arc behavior under cross-flows at a spark plug typically used in gas engines. The test rig consists of a closed flow circuit for inert gases; its centerpiece is a test cell that provides optical access for high-speed imaging of the electric arc behavior at the spark plug. The required flow velocity at the spark plug is set with a blower. Flow velocities up to 30 m/s, pressures up to 60 bar and temperatures up to 80 °C can be achieved inside the flow system at the location of the spark plug. Postprocessing algorithms have been developed to automatically extract information from the high-speed images. The results reveal that the arc stretches more at a higher flow velocity as indicated by its greater arc length. In addition, it is evident that the cycle-to-cycle variation in arc length increases at higher flow velocities. The secondary voltage history and its cycle-to-cycle variation are strongly influenced by the arc length. This is reflected in the cycle-to-cycle variation of the spark energy input to the flowing gas. These results support the conclusion that spark behavior itself can be a substantial source of cycle-to-cycle variation in the combustion process observed in spark ignited gas engines.

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