scholarly journals Determination of distributions of key physical parameters of plasma jet particles by means of image stream processing during high-speed video filming

2019 ◽  
Vol 1333 ◽  
pp. 032031
Author(s):  
V I Jordan ◽  
D I Kobelev
Keyword(s):  
High Speed ◽  
Stream Processing ◽  
Plasma Jet ◽  
Physical Parameters ◽  
High Speed Video ◽  
Image Stream

scholarly journals CNN-based visual analysis to study local boiling characteristics

2021 ◽  
Vol 2119 (1) ◽  
pp. 012068
Author(s):  
A N Chernyavskiy ◽  
I P Malakhov
Keyword(s):  
Network Architecture ◽  
High Speed ◽  
Visual Analysis ◽  
Nucleation Site ◽  
High Speed Video ◽  
Site Density ◽  
Segmentation Approach ◽  
Nucleation Site Density ◽  
Instance Segmentation

Abstract Visual analysis allows an estimate of different local boiling characteristics including bubble growth rate, departure diameters and frequencies of nucleation, nucleation site density and evolution of bubbles and dry spots in time. At the same time, visual determination of the presented characteristics in case of big amounts of data requires the development of the appropriate software which will allow not only determination of bubble location, but also an estimate of their sizes based on high-speed video. The presented problem can be solved by using the instance segmentation approach based on a convolutional neural network. In the presented work Mask R-CNN network architecture was used for estimation of the local boiling characteristics.

Anode Boundary Layer Effects in Plasma Spray Torches

2000 ◽  
Author(s):  
Z. Duan ◽  
J. Heberlein
Keyword(s):  
Boundary Layer ◽  
Plasma Torch ◽  
High Speed ◽  
Plasma Jet ◽  
Coating Quality ◽  
Gas Entrainment ◽  
Framing Rate ◽  
Mass Flow Rates ◽  
Cold Gas

Abstract The control over coating quality in plasma spraying is partly dependent on the arc and jet instabilities of the plasma torch. Different forms of instabilities have been observed with different effects on the coating quality. We report on an investigation of these instabilities based on high-speed end-on observation of the arc. The framing rate of 40,500 frames per second has allowed the visualization of the anode attachment movement and the determination of the thickness of the cold gas boundary layer surrounding the arc. The images have been synchronized with voltage traces. Data have been obtained for a range of arc currents, mass flow rates, for different gas injectors and for anodes displaying different amounts of wear. The analysis of the data has led to quantitative correlations between the cold gas boundary layer thickness and the instability mode for the range of operating parameters. The arc instabilities can be seen to enhance the plasma jet instabilities and the cold gas entrainment. These results are particular useful for guiding plasma torch design and operation to minimize the influence of plasma jet instabilities on coating properties.

scholarly journals Temperature evaluation of a hyper-rapid plasma jet by the method of high-speed video recording

2016 ◽  
Vol 124 ◽  
pp. 012001
Author(s):  
A E Rif ◽  
V V Cherevko ◽  
A S Ivashutenko ◽  
N V Martyushev ◽  
N Ye Nikonova
Keyword(s):  
High Speed ◽  
Video Recording ◽  
Plasma Jet ◽  
High Speed Video

scholarly journals Determination of the geometry of laser-cutting fronts with high spatial and temporal resolution

2021 ◽  
Vol 1135 (1) ◽  
pp. 012013
Author(s):  
Michael Sawannia ◽  
Peter Berger ◽  
Rudolf Weber ◽  
Thomas Graf
Keyword(s):  
Laser Power ◽  
High Speed ◽  
Frame Rate ◽  
Laser Fusion ◽  
Normal Vector ◽  
Local Surface ◽  
Aisi 304 ◽  
High Speed Video ◽  
Laser Fusion Cutting

Abstract The melt flow velocity and the local surface angles of the cutting front during laser fusion cutting of 10 mm AISI 304 were determined for a laser power of 8 kW and a feed rate of 2 m/min. The cut front was recorded with a polarization goniometer, which uses the polarization of the process emission to determine the local surface angles, allowing to calculate the orientation of the normal vector of the surface. The records in this work were carried out with a frame rate of 75 kHz and a spatial resolution of about 30 µm. This allowed to identify big and small structures moving down the cutting front and to determine their velocities. The approximate velocity of the small structures was 9.1 m/s and for the big structures approx. 2.5 m/s. The information of a usual high-speed video was compared with the additionally obtained geometry information.

Determination of the high-speed plasma jet injection parameters in the "Fluxus" experiments

2021 ◽  
Author(s):  
Tatiana Losseva ◽  
Anatoly Golub' ◽  
Igor Kosarev ◽  
Yury Poklad ◽  
Andrey Lyakhov
Keyword(s):  
High Speed ◽  
Plasma Jet ◽  
Jet Injection ◽  
Injection Parameters

Optimum Backwashing of Filters with Air Scour: A Review

1993 ◽  
Vol 27 (10) ◽  
pp. 195-211 ◽  
Author(s):  
Appiah Amirtharajah
Keyword(s):  
High Speed ◽  
Computer Hardware ◽  
Cleaning Process ◽  
Water Flows ◽  
High Speed Video ◽  
Water Treatment Plants ◽  
Model Filter ◽  
The Media ◽  
Air Pockets

The problems occurring in the filtration facilities of water treatment plants, such as mudballs and poor initial filtrate quality are associated with the effectiveness of backwashing. Backwashing with water alone to fluidize the media is an inherently weak cleaning process. The effectiveness of backwashing is significantly improved by the use of air scour simultaneously with subfluidization water wash. When air and subfluidization water flowed concurrently through porous media, a condition termed “collapse- pulsing” occurred in which air pockets formed and collapsed within the bed. A theory has been developed that predicted the combinations of air and water flows that caused collapse-pulsing to occur. Model filter systems have shown that the fluid mechanical condition termed “collapse-pulsing” is also the condition of optimum removal of particles from the media grains during backwashing. The theoretical aspects of collapse-pulsing have been confirmed with an experimental filter system having an endoscope, high speed video system with freeze frame capability for visual observations and an XY Coordinator with computer hardware and software which enabled the determination of velocities of filter grains during air scour. Additional studies on optimum removal of particles from media during air scour have also demonstrated that the results may be extended to dual media filters and are valid at the plant scale too.

APPLICATION OF THE EARLY DAMAGE DIAGNOSTICS TECHNIQUE TO EXAMINATION OF THE AVIATION PANEL

2019 ◽  
Vol 85 (6) ◽  
pp. 53-63 ◽  
Author(s):  
I. E. Vasil’ev ◽  
Yu. G. Matvienko ◽  
A. V. Pankov ◽  
A. G. Kalinin
Keyword(s):  
Acoustic Emission ◽  
Damage Detection ◽  
High Speed ◽  
Early Stage ◽  
Video Data ◽  
High Speed Video ◽  
Damage Diagnostics ◽  
Subsurface Defect ◽  
Sensitive Coating ◽  
Early Damage

The results of using early damage diagnostics technique (developed in the Mechanical Engineering Research Institute of the Russian Academy of Sciences (IMASH RAN) for detecting the latent damage of an aviation panel made of composite material upon bench tensile tests are presented. We have assessed the capabilities of the developed technique and software regarding damage detection at the early stage of panel loading in conditions of elastic strain of the material using brittle strain-sensitive coating and simultaneous crack detection in the coating with a high-speed video camera “Video-print” and acoustic emission system “A-Line 32D.” When revealing a subsurface defect (a notch of the middle stringer) of the aviation panel, the general concept of damage detection at the early stage of loading in conditions of elastic behavior of the material was also tested in the course of the experiment, as well as the software specially developed for cluster analysis and classification of detected location pulses along with the equipment and software for simultaneous recording of video data flows and arrays of acoustic emission (AE) data. Synchronous recording of video images and AE pulses ensured precise control of the cracking process in the brittle strain-sensitive coating (tensocoating)at all stages of the experiment, whereas the use of structural-phenomenological approach kept track of the main trends in damage accumulation at different structural levels and identify the sources of their origin when classifying recorded AE data arrays. The combined use of oxide tensocoatings and high-speed video recording synchronized with the AE control system, provide the possibility of definite determination of the subsurface defect, reveal the maximum principal strains in the area of crack formation, quantify them and identify the main sources of AE signals upon monitoring the state of the aviation panel under loading P = 90 kN, which is about 12% of the critical load.

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