Physical characterization of the optical transmission path for digital high-speed camera observation of vacuum arcs

Author(s):  
B. Kuehn ◽  
T. Kopp ◽  
B. Weber ◽  
C. Dorsch ◽  
V. Hinrichsen ◽  
...  
2019 ◽  
Vol 87 (3) ◽  
pp. 30901
Author(s):  
Romaric Landfried ◽  
Mohamed Boukhlifa ◽  
Thierry Leblanc ◽  
Philippe Teste ◽  
Jonathan Andrea

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.


2005 ◽  
Vol 896 ◽  
Author(s):  
Louis Ferranti ◽  
Naresh N. Thadhani

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.


2013 ◽  
Vol 10 (85) ◽  
pp. 20130227 ◽  
Author(s):  
Kyung-Ah Kwon ◽  
Rebecca J. Shipley ◽  
Mohan Edirisinghe ◽  
Daniel G. Ezra ◽  
Geoff Rose ◽  
...  

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.


2014 ◽  
Author(s):  
Jian James Zhang ◽  
Danop Rajabhandharaks ◽  
Jason Rongwei Xuan ◽  
Ray W. J. Chia ◽  
Tom Hasenberg

2018 ◽  
Vol 52 (6) ◽  
pp. 065201 ◽  
Author(s):  
Sven Gröger ◽  
Marleen Ramakers ◽  
Marc Hamme ◽  
Jose A Medrano ◽  
Nikita Bibinov ◽  
...  

Author(s):  
Amol Kulkarni ◽  
Amey Vidvans ◽  
Mustafa Rifat ◽  
Gregory Bicknell ◽  
Xi Gong ◽  
...  

The present work delineates a novel and scalable approach to characterization of defects in additively manufactured components. The approach is based on digital image correlation and involves characterization of surface speeds during rigid body rotation of the workpiece, followed by normalization with respect to rotation speed. Towards this, two different imaging sources were tested, viz. smartphone camera and sophisticated high-resolution/high-speed camera. The proposed approach successfully delineated horizontal and vertical notch defects in a simple FDM fabricated component. Accuracy of this approach was tested with concomitant laser based scanning. Some limitations of this approach were discussed.


Sadhana ◽  
2020 ◽  
Vol 45 (1) ◽  
Author(s):  
Manasa Ram Kotal ◽  
Somnath De ◽  
Soumyadeep Das ◽  
Swarnendu Sen

2020 ◽  
Vol 91 (1) ◽  
pp. 10301
Author(s):  
Zhi Yang ◽  
Guoqiang Zheng ◽  
Peng Zhu ◽  
Cong Xu ◽  
Qiu Zhang ◽  
...  

Parallel bridge foils (PBF) with four strip foils, which is derived from traditional single bridge foil (SBF), was designed to study the effect of convergence and collision of plasmas and shock waves on driving flyer. Firstly, Electro-thermal simulation of PBF was performed to analyze temperature distribution before melting, which predicted the synchronous burst characteristic of PBF. Subsequently, a capacitor discharging circuit was designed to initiate bridge foils, results indicated PBF reached higher burst power in shorter time compared with SBF due to better matching between PBF and the test circuit. The flow fields of electrical explosion of bridge foils were photographed by ultra-high-speed camera, which displayed PBF almost burst simultaneously. Moreover, PBF had wider and brighter flow field visualization than SBF owing to convergence and superposition of plasma beams. Most importantly, flyer-accelerators inserted with bridge foils were prepared by MEMS technology, and comparative analysis from PDV revealed MEMS flyer-accelerator inserted with PBF had access to better velocity performances, compared with that inserted with SBF. For instance, PBF flyer-accelerator spent mere 168 ns to 2325 m/s at 900 V/0.22 µF, but SBF flyer-accelerator took 335 ns to 1073 m/s. Finally, we proposed a mathematical model for explaining the enhancement effect of flyer velocity, which to some extent showed good agreement with experimentation.


1986 ◽  
Vol 108 (1) ◽  
pp. 109-114 ◽  
Author(s):  
M. J. Tan ◽  
S. G. Bankoff

Fragmentation of mercury drops falling through a bubbly aqueous liquid by a pressure shock wave was investigated by means of a shock tube capable of operating at driver pressures up to 3 MPa. The responses to moderately strong shock waves (up to 1.7 MPa) were photographed by a high-speed camera at rates of up to 4400 frames per second. The results show the existence of a critical Weber number, (We)cr = 17, for drop fragmentation. Qualitative characterization of the shock-drop interactions for single mercury drops is provided.


Sign in / Sign up

Export Citation Format

Share Document