Spray Characterization of a Slinger Injector Using a High-Speed Imaging Technique

2018 ◽  
Vol 34 (2) ◽  
pp. 469-481 ◽  
Author(s):  
S. Rezayat ◽  
M. Farshchi ◽  
H. Karimi ◽  
A. Kebriaee
Keyword(s):  
High Speed ◽  
Imaging Technique ◽  
High Speed Imaging ◽  
Spray Characterization

Combined Characterization of Free-Moving Particles in HVDC-GIS Using UHF PD, High-Speed Imaging, and Pulse-Sequence Analysis

2019 ◽  
Vol 34 (4) ◽  
pp. 1540-1548 ◽  
Author(s):  
Philipp Wenger ◽  
Michael Beltle ◽  
Stefan Tenbohlen ◽  
Uwe Riechert ◽  
Glenn Behrmann
Keyword(s):  
Sequence Analysis ◽  
High Speed ◽  
Pulse Sequence ◽  
High Speed Imaging

scholarly journals Measuring droplet fall speed with a high-speed camera: indoor accuracy and potential outdoor applications

2016 ◽  
Vol 9 (4) ◽  
pp. 1755-1766 ◽  
Author(s):  
Cheng-Ku Yu ◽  
Pei-Rong Hsieh ◽  
Sandra E. Yuter ◽  
Lin-Wen Cheng ◽  
Chia-Lun Tsai ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging Technique ◽  
High Speed Camera ◽  
High Speed Imaging ◽  
Ambient Flow ◽  
Mean Error ◽  
Challenging Issue ◽  
Size Relationship ◽  
Fall Speed ◽  
Moderate Cost

Abstract. Acquisition of accurate raindrop fall speed measurements outdoors in natural rain by means of moderate-cost and easy-to-use devices represents a long-standing and challenging issue in the meteorological community. Feasibility experiments were conducted to evaluate the indoor accuracy of fall speed measurements made with a high-speed camera and to evaluate its capability for outdoor applications. An indoor experiment operating in calm conditions showed that the high-speed imaging technique can provide fall speed measurements with a mean error of 4.1–9.7 % compared to Gunn and Kinzer's empirical fall-speed–size relationship for typical sizes of rain and drizzle drops. Results obtained using the same apparatus outside in summer afternoon showers indicated larger positive and negative velocity deviations compared to the indoor measurements. These observed deviations suggest that ambient flow and turbulence play a role in modifying drop fall speeds which can be quantified with future outdoor high-speed camera measurements. Because the fall speed measurements, as presented in this article, are analyzed on the basis of tracking individual, specific raindrops, sampling uncertainties commonly found in the widely adopted optical disdrometers can be significantly mitigated.

scholarly journals In-situ characterization of laser-powder interaction and cooling rates through high-speed imaging of powder bed fusion additive manufacturing

2017 ◽  
Vol 135 ◽  
pp. 385-396 ◽  
Author(s):  
Umberto Scipioni Bertoli ◽  
Gabe Guss ◽  
Sheldon Wu ◽  
Manyalibo J. Matthews ◽  
Julie M. Schoenung
Keyword(s):  
Additive Manufacturing ◽  
High Speed ◽  
Powder Bed Fusion ◽  
In Situ Characterization ◽  
High Speed Imaging ◽  
Cooling Rates ◽  
Powder Bed

scholarly journals Measuring Droplet Fall Speed with a High-Speed Camera: Indoor Accuracy and Potential Outdoor Applications

2016 ◽  
Author(s):  
C.-K. Yu ◽  
P.- R. Hsieh ◽  
S. E. Yuter ◽  
L.- W. Cheng ◽  
C.- L. Tsai ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging Technique ◽  
High Speed Camera ◽  
High Speed Imaging ◽  
Ambient Flow ◽  
Mean Error ◽  
Challenging Issue ◽  
Rain Drop ◽  
Rain Drops ◽  
Fall Speed

Abstract. The acquisition of accurate rain drop fall speed measurements outdoors in natural rain represents a long-standing and challenging issue in the meteorological community. Feasibility experiments were conducted to evaluate the indoor accuracy of fall speed measurements made with a high-speed camera and to evaluate its capability for outdoor applications. An indoor experiment operating in calm conditions showed that the high-speed imaging technique can provide fall speed measurements with a mean error of 4.1~9.7% compared to Gunn and Kinzer’s empirical fall speed-size relationship for typical sizes of rain and drizzle drops. Results obtained using the same apparatus outside in summer afternoon showers indicated larger, positive and negative velocity deviations compared to the indoor measurements. These observed deviations suggest that ambient flow and turbulence play a role in modifying drop fall speeds which can be quantified with future outdoor high-speed camera measurements. Because the fall speed measurements, as presented in this article, are analyzed on the basis of tracking individual, specific rain drops, sampling uncertainties commonly found in the widely adopted optical disdrometers can be significantly mitigated.

Comparison of Atomization Characteristics of Jet A-1 and Alternative Aviation Fuels Using High-Speed Imaging Technique

2019 ◽  
Author(s):  
Manish Kumar ◽  
Srinibas Karmakar
Keyword(s):  
Surface Tension ◽  
High Speed ◽  
Alternative Fuels ◽  
Imaging Technique ◽  
Droplet Formation ◽  
Fuel Properties ◽  
Slight Variation ◽  
High Speed Imaging ◽  
Butyl Butyrate ◽  
Atomization Characteristics

Abstract Environmental pollution from gas turbine engines is becoming a serious concern recently because of the steep growth in the aviation sector globally. Therefore, potential alternative fuels which can partially or fully replace fossil-based jet fuel are getting significant attention. However, the search for suitable candidate fuels which can fulfill the requirement in terms of fuel properties and combustion performance is continuing. The present study deals with an experimental investigation of atomization characteristics of Jet A-1, butanol, and butyl butyrate in quiescent atmospheric air. A high-speed imaging technique has been adopted to make a comparison of ligament breakup characteristics and droplet formation of these alternative biofuels with that of Jet A-1. Various fuel properties, including density, viscosity, and surface tension, are compared. An effort is made to understand how the variation in fuel properties influences the atomization mechanism of each fuel. The surface tension seems to be similar for these three fuels with a slight variation in density. However, there is a significant variation in viscosity. Viscosity appears to play a major role in the difference observed in ligament length and droplet formation. Due to the higher viscosity of butanol, the droplet formation seems to be delayed compared to Jet A-1, whereas the lower viscosity of butyl butyrate promotes faster droplet formation. The effect of blending of these biofuels with Jet A-1 on atomization characteristics will be compared with that of Jet A-1.

A Novel High-Speed Imaging Technique to Predict the Macroscopic Spray Characteristics of Solution Based Pressurised Metered Dose Inhalers

2014 ◽  
Vol 31 (11) ◽  
pp. 2963-2974 ◽  
Author(s):  
Nicolas A. Buchmann ◽  
Daniel J. Duke ◽  
Sayed A. Shakiba ◽  
Daniel M. Mitchell ◽  
Peter J. Stewart ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging Technique ◽  
Metered Dose Inhalers ◽  
High Speed Imaging ◽  
Spray Characteristics ◽  
Metered Dose ◽  
Pressurised Metered Dose Inhalers

Nanomanipulator Based on a High-Speed Atomic Force Microscopy

2012 ◽  
Vol 516 ◽  
pp. 396-401
Author(s):  
Itsuhachi Ishisaki ◽  
Yuya Ohashi ◽  
Tatsuo Ushiki ◽  
Futoshi Iwata
Keyword(s):  
Atomic Force Microscopy ◽  
Real Time ◽  
High Speed ◽  
Imaging Technique ◽  
Frame Rate ◽  
High Speed Imaging ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Short Time

We developed a real-time nanomanipulation system based on high-speed atomic force microscopy (HS-AFM). During manipulation, the operation of the manipulation is momentarily interrupted for a very short time for high-speed imaging; thus, the topographical image of the fabricated surface is periodically updated during the manipulation. By using a high-speed imaging technique, the interrupting time could be much reduced during the manipulation; as a result, the operator almost does not notice the blink time of the interruption for imaging during the manipulation. As for the high-speed imaging technique, we employed a contact-mode HS-AFM to obtain topographic information through the instantaneous deflection of the cantilever during high-speed scanning. By using a share motion PZT scanner, the surface could be imaged with a frame rate of several fps. Furthermore, the high-speed AFM was coupled with a haptic device for human interfacing. By using the system, the operator can move the AFM probe into any position on the surface and feel the response from the surface during manipulation. As a demonstration of the system, nanofabrication under real-time monitoring was performed. This system would be very useful for real-time nanomanipulation and fabrication of sample surfaces.

Three-Dimensional Structural Characterization of Nonwoven Fabrics

2012 ◽  
Vol 18 (6) ◽  
pp. 1368-1379 ◽  
Author(s):  
Lalith B. Suragani Venu ◽  
Eunkyoung Shim ◽  
Nagendra Anantharamaiah ◽  
Behnam Pourdeyhimi
Keyword(s):  
High Speed ◽  
Imaging Technique ◽  
Low Cost ◽  
Three Dimensional ◽  
Complex Nature ◽  
Volumetric Imaging ◽  
Analysis Techniques ◽  
Nonwoven Fabrics ◽  
Nonwoven Materials

AbstractNonwoven materials are found in a gamut of critical applications. This is partly due to the fact that these structures can be produced at high speed and engineered to deliver unique functionality at low cost. The behavior of these materials is highly dependent on alignment of fibers within the structure. The ability to characterize and also to control the structure is important, but very challenging due to the complex nature of the structures. Thus, to date, focus has been placed mainly on two-dimensional analysis techniques for describing the behavior of nonwovens. This article demonstrates the utility of three-dimensional (3D) digital volumetric imaging technique for visualizing and characterizing a complex 3D class of nonwoven structures produced by hydroentanglement.

scholarly journals Real-Time Defects Analyses Using High-Speed Imaging during Aluminum Magnesium Alloy Laser Welding

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1877
Author(s):  
Sabin Mihai ◽  
Diana Chioibasu ◽  
Muhammad Arif Mahmood ◽  
Liviu Duta ◽  
Marc Leparoux ◽  
...  
Keyword(s):  
Real Time ◽  
High Speed ◽  
Yttrium Aluminum Garnet ◽  
Continuous Wave ◽  
Threshold Value ◽  
High Speed Imaging ◽  
Vapor Plume ◽  
Imaging Camera ◽  
Microscopy Images

In this study a continuous wave Ytterbium-doped Yttrium Aluminum Garnet (Yb: YAG) disk laser has been used for welding of AlMg3 casted alloy. A high-speed imaging camera has been employed to record hot vapor plume features during the process. The purpose was to identify a mechanism of pores detection in real-time based on correlations between metallographic analyses and area/intensity of the hot vapor in various locations of the samples. The pores formation and especially the position of these pores had to be kept under control in order to weld thick samples. Based on the characterization of the hot vapor, it has been found that the increase of the vapor area that exceeded a threshold value (18.5 ± 1 mm2) was a sign of pores formation within the weld seam. For identification of the pores’ locations during welding, the monitored element was the hot vapor intensity. The hot vapor core spots having a grayscale level reaching 255 was associated with the formation of a local pore. These findings have been devised based on correlation between pores placement in welds cross-section microscopy images and the hot vapor plume features in those respective positions.

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