scholarly journals High-Speed Photography and Digital Optical Measurement Techniques for Geomaterials: Fundamentals and Applications

2017 ◽  
Vol 50 (6) ◽  
pp. 1611-1659 ◽  
Author(s):  
H. Z. Xing ◽  
Q. B. Zhang ◽  
C. H. Braithwaite ◽  
B. Pan ◽  
J. Zhao
Keyword(s):  
High Speed ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
High Speed Photography

Realization of a Fully Optically Accessible Medium Speed Large Bore Engine Using a Fisheye Optic

2020 ◽  
Author(s):  
Stephan Karmann ◽  
Christian Friedrich ◽  
Maximilian Prager ◽  
Georg Wachtmeister
Keyword(s):  
High Speed ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Combustion Process ◽  
Engine Operation ◽  
New Approach ◽  
Medium Speed ◽  
Starting Point ◽  
Nominal Load ◽  
Fire Engine

Abstract To address one of the main environmental concerns, the engine out emissions, an enhanced understanding of the combustion process itself is fundamental. Recent optical and laser optical measurement techniques provide a promising approach to investigate and optimize the combustion process regarding emissions. These measurement techniques are already quite common for passenger car and truck size engines and significantly contribute to their improvement. Transferring these measurement techniques to large bore engines from low to high speed is still rather more uncommon especially due to the bigger challenges caused by the engine size and thus much higher stability requirements and design effort for optical accessibility. To cover this new field of research a new approach for a medium speed large bore engine was developed using a fisheye optic mounted centrally in the cylinder head to design a fully optically accessible engine test bench. This new approach is detailed with a test setup layout and a stability concept consisting of cooling systems and the development of a suitable operation strategy based on simulation and experimental verification. The design of this single cylinder engine with 350mm bore and 440mm stroke providing 530kW nominal load at 750 rpm was tested up to 85% nominal load in skipped fire engine operation mode. The measurements of the flame chemiluminescence of a dual fuel combustion of the diesel gas type present proof of the feasibility of the new design as a starting point for future systematic studies on the combustion process of large bore engines.

Investigating the Flexural Behaviour of Foams at High Strain Rate Using Optical Measurement Techniques

2013 ◽  
Vol 569-570 ◽  
pp. 799-804
Author(s):  
Duncan A. Crump ◽  
Janice M. Dulieu-Barton
Keyword(s):  
High Speed ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Maximum Load ◽  
Image Correlation ◽  
Test Machine ◽  
Full Field ◽  
Closed Cell ◽  
Load To Failure ◽  
Point Bend

Polymer closed cell foam beam specimens manufactured from H100 Divinycell (Diab) are tested in four point bend at three loading speeds using a specially designed rig and an Instron VHS test machine. Synchronised high speed images are captured using white light and infra-red thermography (IRT) to obtain the mid-point full-field deflection and strains using digital image correlation (DIC) along with the temperature evolutions. There is a marked increase in the maximum load to failure with loading rate and the optical techniques provide an opportunity to analyse the strain and temperature evolution within the specimens.

Application of High-Speed OH-PLIF Technique for Improvement of Lean Hydrogen-Air Combustion Modeling

2016 ◽  
Author(s):  
Peter Katzy ◽  
Lorenz R. Boeck ◽  
Josef Hasslberger ◽  
Thomas Sattelmayer
Keyword(s):  
High Speed ◽  
Optical Measurement ◽  
Initial Conditions ◽  
Measurement Techniques ◽  
Evaluation Methods ◽  
Line Of Sight ◽  
Flame Surface ◽  
Validation Data ◽  
Time Resolved ◽  
Wrinkled Flame

The presented work aims to improve CFD explosion modeling for lean hydrogen-air mixtures on under-resolved grids. Validation data is obtained from an entirely closed laboratory scale explosion channel (GraVent facility). Investigated hydrogen-air concentrations range from 6 to 19 vol.-%. Initial conditions are p = 1 atm and T = 293 K. Two highly time-resolved optical measurement techniques are applied simultaneously: (1) 10 kHz shadowgraphy captures line-of-sight integrated macroscopic flame propagation; and (2) 20 kHz OH-PLIF (planar laser-induced fluorescence of the OH radical) resolves microscopic flame topology without line-of-sight integration. This paper presents the experiment, measurement techniques, data evaluation methods and initial results. The evaluation methods encompass the determination of flame tip velocity over distance and a detailed time-resolved quantification of flame topology based on OH-PLIF images. One parameter is the length of wrinkled flame fronts in the OH-PLIF plane obtained through automated post-processing. It reveals the expected enlargement of flame surface area by instabilities on microscopic level. A strong effect of mixture composition is observed.

Crack divergence phenomena in tempered glass

2020 ◽  
Vol 13 (3) ◽  
pp. 115-129
Author(s):  
Shin’ichi Aratani
Keyword(s):  
Optimal Design ◽  
High Speed ◽  
Glass Plate ◽  
Acute Angle ◽  
Divergence Angle ◽  
High Speed Photography ◽  
Tempered Glass ◽  
Thick Glass

High speed photography using the Cranz-Schardin camera was performed to study the crack divergence and divergence angle in thermally tempered glass. A tempered 3.5 mm thick glass plate was used as a specimen. It was shown that two types of bifurcation and branching existed as the crack divergence. The divergence angle was smaller than the value calculated from the principle of optimal design and showed an acute angle.

Experimental study of hydrodynamic effects in the inverse water hydrocarbon emulsions flow in microchannels

2016 ◽  
Vol 11 (1) ◽  
pp. 30-37 ◽  
Author(s):  
A.A. Rakhimov ◽  
A.T. Akhmetov
Keyword(s):  
High Speed ◽  
Petroleum Industry ◽  
Chemical Compounds ◽  
High Viscosity ◽  
Blocking Effect ◽  
High Speed Photography ◽  
Simple Chemical ◽  
Reported Study ◽  
Dynamic Blocking ◽  
Hydrodynamic Effects

The paper presents results of hydrodynamic and rheological studies of the inverse water hydrocarbon emulsions. The success of the application of invert emulsions in the petroleum industry due, along with the high viscosity of the emulsion, greatly exceeding the viscosity of the carrier phase, the dynamic blocking effect, which consists in the fact that the rate of flow of emulsions in capillary structures and cracks falls with time to 3-4 orders, despite the permanent pressure drop. The reported study shows an increase in viscosity with increasing concentration or dispersion of emulsion. The increase in dispersion of w/o emulsion leads to an acceleration of the onset of dynamic blocking. The use of microfluidic devices, is made by soft photolithography, along with high-speed photography (10,000 frames/s), allowed us to see in the blocking condition the deformation of the microdroplets of water in inverse emulsion prepared from simple chemical compounds.

Fundamentals Of High-Speed Photography

1973 ◽  
Author(s):  
J. A. Lafer, Jr.
Keyword(s):  
High Speed ◽  
High Speed Photography
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