scholarly journals Simulation of flow development in high-speed combustor in 2D and 3D formulations

2018 ◽  
Author(s):  
V. V. Vlasenko ◽  
E. S. Matyash ◽  
S. S. Molev ◽  
V. A. Sabelnikov ◽  
V. A. Talyzin
Keyword(s):  
High Speed ◽  
Flow Development ◽  
2D And 3D

scholarly journals Secondary Atomization of a Biodiesel Micro-Emulsion Fuel Droplet Colliding with a Heated Wall

2020 ◽  
Vol 10 (2) ◽  
pp. 685 ◽  
Author(s):  
Alexander E. Ashikhmin ◽  
Nikita A. Khomutov ◽  
Maxim V. Piskunov ◽  
Vyacheslav A. Yanovsky
Keyword(s):  
Surface Area ◽  
High Speed ◽  
Heating Temperature ◽  
Video Recording ◽  
Heated Wall ◽  
Fuel Droplet ◽  
Area Increase ◽  
Micro Emulsion ◽  
2D And 3D ◽  
Surface Area Increase

Using high-speed video recording, we establish the following regimes of hydrodynamic interaction of a biodiesel micro-emulsion fuel droplet with a heated wall: deposition (including drop spreading and receding), drop hydrodynamic breakup, and rebound. Collision regime maps are plotted using a set of dimensionless criteria: Weber number We = 470–1260, Ohnesorge number Oh = 0.146–0.192, and Reynolds number Re = 25–198. The scenarios of droplet hydrodynamic disintegration are studied for transient and film boiling. We also estimate the disintegration characteristics of a biodiesel micro-emulsion droplet (mean diameter of child droplets, their number, and evaporation surface area increase due to breakup). The study establishes the effect of water proportion on the micro-emulsion composition (8–16 vol.%), heating temperature (300–500 °C), droplet size (1.8–2.8 mm), droplet velocity (3–4 m/s), rheological properties of the examined compositions, and emulsifier concentration (10.45 vol.% and 20 vol.%) on the recorded characteristics. The results show that the initial liquid surface area can be increased 2–19 times. The paper analyzes ways to control the process. The hydrodynamic disintegration characteristics of a biodiesel micro-emulsion fuel droplet are compared using 2D and 3D recording.

scholarly journals An Evaluation of Temporal and Club Angle Parameters During Golf Swings Using Low Cost Video Analyses Packages

2022 ◽  
Author(s):  
Henry H. Hunter ◽  
Ukadike C. Ugbolue ◽  
Graeme G. Sorbie ◽  
Wing-Kai Lam ◽  
Fergal M. Grace ◽  
...  
Keyword(s):  
High Speed ◽  
Low Cost ◽  
Cost Effective ◽  
Video Camera ◽  
Golf Club ◽  
Phase Measurements ◽  
Swing Time ◽  
The Cost ◽  
3D Software ◽  
2D And 3D

Abstract The purpose of this study was to compare swing time and golf club angle parameters during golf swings using three, two dimensional (2D) low cost, Augmented-Video-based-Portable-Systems (AVPS) (Kinovea, SiliconCoach Pro, SiliconCoach Live). Twelve right-handed golfers performed three golf swings whilst being recorded by a high-speed 2D video camera. Footage was then analysed using AVPS-software and the results compared using both descriptive and inferential statistics. There were no significant differences for swing time and the golf phase measurements between the 2D and 3D software comparisons. In general, the results showed a high Intra class Correlation Coefficient (ICC > 0.929) and Cronbach’s Coefficient Alpha (CCA > 0.924) reliability for both the kinematic and temporal parameters. The inter-rater reliability test for the swing time and kinematic golf phase measurements on average were strong. Irrespective of the AVPS software investigated, the cost effective AVPS can produce reliable output measures that benefit golf analyses.

Flow Development of a Liquid Sheet Issued Into Low-Speed Airstream

2020 ◽  
Author(s):  
Amin Jaberi ◽  
Mehran Tadjfar
Keyword(s):  
High Speed ◽  
Liquid Sheet ◽  
Liquid Jets ◽  
High Speed Photography ◽  
Low Speed ◽  
Liquid Sheets ◽  
Flow Development ◽  
Flow Feature ◽  
Subsonic Crossflow ◽  
Jet Characteristics

Abstract In this study, a liquid sheet with an aspect ratio of 90 and a thickness of 0.35 was experimentally investigated when issued into a low-speed subsonic crossflow. High speed photography and shadowgraphy technique were employed to capture the instantaneous physics of the liquid sheet. Flow visualizations were used to investigate the flow development of the liquid sheet. It was found that this flow exhibited a completely different flow structure than circular or other non-circular liquid sheets. It was found that the liquid sheet developed a concave-like shape in the presence of the transverse airstream. This phenomenon, named as inflated sheet, was absent in regular circular liquid jets injected into gaseous crossflow. It was revealed the inflated sheet was the main feature of the liquid sheet that made the jet characteristics unique. The flow feature of the inflated sheet structure and its alteration with flow condition was fully examined. Moreover, the width and trajectory of the liquid sheet were quantitatively studied at different Weber numbers and for the constant momentum ratio of 40. It was found that the fluid width could be a useful parameter to distinguish different regimes of the flow.

Suspension Mixing and Segregation in 1D, 2D, and 3D Flows

2007 ◽  
Author(s):  
James F. Gilchrist ◽  
Changbao Gao
Keyword(s):  
High Speed ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Chaotic Advection ◽  
Confocal Laser ◽  
Particle Velocities ◽  
Complicated Geometries ◽  
3D Flows ◽  
2D And 3D ◽  
Suspension Structure

Particles in concentrated flowing suspension in pressure-driven flows tend to migrate away from the walls toward the center of the channel. Demixing due to shear-induced migration inhibits mixing and near wall transport. We investigate the competition between mixing and segregation in flows with complicated geometries that generate 3D chaotic advection, resulting in nontrivial concentration patterns. Using high-speed confocal laser scanning microscopy, we directly image the microspheres to measure the interplay between chaotic advection and the 3D spatial concentration profile, local particle velocities, and suspension structure.

Direct Measurement of Skin Friction in Complex Fluid Flows

1997 ◽  
Vol 50 (11S) ◽  
pp. S198-S203 ◽  
Author(s):  
Joseph A. Schetz
Keyword(s):  
Skin Friction ◽  
Direct Measurement ◽  
High Speed ◽  
Fluid Flows ◽  
Measurement Results ◽  
Hypersonic Speeds ◽  
Complex Fluid ◽  
3D Flows ◽  
2D And 3D ◽  
Very High

This paper describes methods for the direct measurement of skin friction in fluid flows under a very wide variety of conditions. The challenges involved in different flow situations are highlighted, and representative instrument designs and measurement results are presented. The test conditions considered span the range from incompressible to hypersonic speeds; ambient to very high temperature including combusting flows; smooth, rough, and porous surfaces with and without injection and test times from 10-6 to essentially continuous runs. Both 2D and 3D flows are discussed. Accuracies of +/- 3-5% are presently attainable in the simplest cases, while +/- 10-15% is more typical for complex, 3D, high-speed flows at high temperatures. The final topic discussed is simultaneous measurements of skin friction and heat flux with the possible further additions of surface pressure and temperature.

scholarly journals Three-Dimensional VHF Lightning Mapping System for Winter Thunderstorms

2013 ◽  
Vol 30 (2) ◽  
pp. 325-335 ◽  
Author(s):  
Masahide Nishihashi ◽  
Ken-ichi Shimose ◽  
Kenichi Kusunoki ◽  
Syugo Hayashi ◽  
Ken-ichiro Arai ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Japan Sea ◽  
Correlation Technique ◽  
Very High Frequency ◽  
Digital Oscilloscope ◽  
Observation Network ◽  
Radiation Sources ◽  
Mapping System ◽  
2D And 3D

Abstract A three-dimensional (3D) winter lightning mapping system employing very high frequency (VHF) broadband signals was developed for continuous remote observation in winter. VHF broadband pulses radiated by leader progression are received with three discone antennas arranged in a triangle (20–30 m) and recorded on a high-speed digital oscilloscope (1.25-GHz sampling) with GPS digital timing data. The two-dimensional (2D) mapping for azimuth and elevation of the VHF radiation sources was conducted by computing the arrival time differences of three pulses using a cross-correlation technique. From azimuth and elevation data from two sites extracted within a given time frame, 3D lightning mapping was performed using the triangulation scheme. An observation network for winter lightning was constructed within a comprehensive meteorological observation network in the Shonai area, which is located on the coast of the Japan Sea. This report includes the preliminary 2D and 3D mapping of winter lightning observed on 3 December 2010. The horizontal and vertical distributions of VHF radiation sources were consistent with the radar echo observed with X-band Doppler radar. These results indicate that the system can detect winter lightning discharges and perform 2D and 3D lightning mapping in detail.

scholarly journals High-Speed Manipulation of Microobjects Using an Automated Two-Fingered Microhand for 3D Microassembly

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 534
Author(s):  
Eunhye Kim ◽  
Masaru Kojima ◽  
Yasushi Mae ◽  
Tatsuo Arai
Keyword(s):  
High Speed ◽  
Positional Error ◽  
Adhesion Forces ◽  
Nih3t3 Cells ◽  
Manipulation System ◽  
Strong Adhesion ◽  
3D Assembly ◽  
End Effectors ◽  
2D And 3D ◽  
Pick And Place Operation

To assemble microobjects including biological cells quickly and precisely, a fully automated pick-and-place operation is applied. In micromanipulation in liquid, the challenges include strong adhesion forces and high dynamic viscosity. To solve these problems, a reliable manipulation system and special releasing techniques are indispensable. A microhand having dexterous motion is utilized to grasp an object stably, and an automated stage transports the object quickly. To detach the object adhered to one of the end effectors, two releasing methods—local stream and a dynamic releasing—are utilized. A system using vision-based techniques for the recognition of two fingertips and an object, as well automated releasing methods, can increase the manipulation speed to faster than 800 ms/sphere with a 100% success rate (N = 100). To extend this manipulation technique, 2D and 3D assembly that manipulates several objects is attained by compensating the positional error. Finally, we succeed in assembling 80–120 µm of microbeads and spheroids integrated by NIH3T3 cells.

F-10 High Speed 2D and 3D MXRF—Imaging with Bench Top Technology

2010 ◽  
Vol 25 (2) ◽  
pp. 210-210
Author(s):  
U. Waldschlaeger ◽  
M. Haschke
Keyword(s):  
High Speed ◽  
2D And 3D
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