High Speed Manyframe Optical Methods For Plasma Diagnostics

1979 ◽  
Author(s):  
A. A. Erokhin ◽  
A. S. Shikanov ◽  
G. V. Sklizkov ◽  
Yu. A. Zakharenkov ◽  
N. N. Zorev
Keyword(s):  
Plasma Diagnostics ◽  
High Speed ◽  
Optical Methods

High Speed Plasma Diagnostics Instrumentation

2000 ◽  
Author(s):  
Andreas Neuber ◽  
M. Kristiansen
Keyword(s):  
Plasma Diagnostics ◽  
High Speed

scholarly journals Cavitation between cylinder-liner and piston-ring in a new designed optical IC engine

2021 ◽  
pp. 146808742110080
Author(s):  
Jamshid Malekmohammadi Nouri ◽  
Ioannis Vasilakos ◽  
Youyou Yan
Keyword(s):  
High Speed ◽  
Contact Point ◽  
Cylinder Liner ◽  
Optical Methods ◽  
Engine Management System ◽  
Great Success ◽  
Ic Engine ◽  
Contact Points ◽  
Lubricant Flow ◽  
Cavitation Intensity

A new engine block with optical access has been designed and manufactured capable of running up to 3000 r/min with the same specification as the unmodified engine. The optical window allowed access to the full length of the liner over a width of 25 mm to investigate the lubricant flow and cavitation at contact point between the rings and cylinder-liner. In addition, it allowed good access into the combustion chamber to allow charged flow, spray and combustion visualisation and measurements using different optical methods. New custom engine management system with build in LabView allowed for the precise full control of the engine. The design of the new optical engine was a great success in producing high quality images of lubricant flow, cavitation formation and development at contact point at different engine speeds ranging from 208 to 3000 r/min and lubricant temperatures (30°C–70°C) using a high-speed camera. The results under motorised operation confirmed that there was no cavitation at contact points during the intake/exhaust strokes due to low in-cylinder presure, while during compression/expansion strokes, with high in-cylinder pressure, considerable cavities were observed, in particular, during the compression stroke. Lubricant temperatures had the effect of promoting cavities both in their intensity and covered ring area up to 50°C as expected. Beyond that, although the cavitation intensity increases further with temperature, its area reduces due to possible collapse of the cavitating bubbles at higher temperature. The change of engine speed from 208 to 800 r/min increased cavitating area considerably by 52% of the ring area and was further increased by 19% at 1000 r/min. After that, the results showed very small increase in cavitation area (1.3% at 2000 r/min) with similar intensity and distribution across the ring.

The Use of Modan 3D in Experimental Modal Analysis

2013 ◽  
Vol 486 ◽  
pp. 36-41 ◽  
Author(s):  
Róbert Huňady ◽  
František Trebuňa ◽  
Martin Hagara ◽  
Martin Schrötter
Keyword(s):  
Modal Analysis ◽  
Vibration Analysis ◽  
High Speed ◽  
Mechanical Vibration ◽  
Steel Sample ◽  
Experimental Modal Analysis ◽  
Image Correlation ◽  
Optical Methods ◽  
Mode Shapes ◽  
Vibration Modes

Experimental modal analysis is a relatively young part of dynamics, which deals with the vibration modes identification of machines or their parts. Its development has started since the beginning of the eighties, when the computers hardware equipment has improved and the fast Fourier transform (FFT) could be used for the results determination. Nowadays it provides an uncountable set of vibration analysis possibilities starting with conventional contact transducers of acceleration and ending with modern noncontact optical methods. In this contribution we mention the use of high-speed digital image correlation by experimental determination of mode shapes and modal frequencies. The aim of our work is to create a program application called Modan 3D enabling the performing of experimental modal analysis and operational modal analysis. In this paper the experimental modal analysis of a thin steel sample performed with Q-450 Dantec Dynamics is described. In Modan 3D the experiment data were processed and the vibration modes were determined. The reached results were verified by PULSE modulus specialized for mechanical vibration analysis.

scholarly journals High speed plasma diagnostics for laser plasma interaction and fusion studies

Sadhana ◽  
1999 ◽  
Vol 24 (6) ◽  
pp. 513-549 ◽  
Author(s):  
V N Rai ◽  
M Shukla ◽  
H C Pant ◽  
D D Bhawalkar
Keyword(s):  
Laser Plasma ◽  
Plasma Diagnostics ◽  
High Speed ◽  
Plasma Interaction ◽  
Laser Plasma Interaction

Investigation of the Flow Structures in Supersonic Free and Impinging Jet Flows

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
C. Chin ◽  
M. Li ◽  
C. Harkin ◽  
T. Rochwerger ◽  
L. Chan ◽  
...  
Keyword(s):  
High Speed ◽  
Numerical Study ◽  
Experimental Studies ◽  
Turbulence Models ◽  
Impinging Jet ◽  
Optical Methods ◽  
Navier Stokes ◽  
Jet Flows ◽  
Shock Cell ◽  
Rans Turbulence Models

A numerical study of compressible jet flows is carried out using Reynolds averaged Navier–Stokes (RANS) turbulence models such as k-ɛ and k-ω-SST. An experimental investigation is performed concurrently using high-speed optical methods such as Schlieren photography and shadowgraphy. Numerical and experimental studies are carried out for the compressible impinging at various impinging angles and nozzle-to-wall distances. The results from both investigations converge remarkably well and agree with experimental data from the open literature. From the flow visualizations of the velocity fields, the RANS simulations accurately model the shock structures within the core jet region. The first shock cell is found to be constraint due to the interaction with the bow-shock structure for nozzle-to-wall distance less than 1.5 nozzle diameter. The results from the current study show that the RANS models utilized are suitable to simulate compressible free jets and impinging jet flows with varying impinging angles.

Image Processing for Optical Methods to Analyze Shape, Deformation, Stress and Strain

2006 ◽  
Vol 326-328 ◽  
pp. 13-18
Author(s):  
Yoshiharu Morimoto
Keyword(s):  
Image Processing ◽  
Real Time ◽  
High Speed ◽  
Video Camera ◽  
Image Sensor ◽  
Phase Shifting ◽  
Optical Methods ◽  
Shape Deformation ◽  
Stress And Strain ◽  
Deformation Stress

The authors have been developing some novel methods to measure shape, deformation, stress and strain of structures using optical methods and image processing as follows: (1) Phase analysis methods using Fourier, wavelet or Gabor transforms, etc., (2) Real-time 2-D strain measurement using moiré interferometry, (3) Scanning moiré method using thinning-out of scanning lines and a DMD camera (4) Strain rate distribution measurement by a high-speed video camera, (5) Real-time integrated phase-shifting method, (6) Shape measurement methods using multi-reference planes, a linear image sensor, or a frequency modulated grating, and (7) Windowed phase-shifting digital holographic interferometry (WPSDHI). Theories of these methods and some applications are introduced. The most accurate result is 88 picometer standard deviation of errors using the WPSDHI.

scholarly journals An Application of the Visualization Methods for Investigation Small Scale Processes in the Atmosphere-hydrosphere Boundary Layer within Laboratory Experiments on the Wind-wave Facilities

2021 ◽  
Author(s):  
Daniil Sergeev ◽  
Anatoly Suvorov ◽  
Alexander Kandaurov
Keyword(s):  
Boundary Layer ◽  
High Speed ◽  
Wind Wave ◽  
Weather Conditions ◽  
Optical Methods ◽  
Small Scale ◽  
Imaging Method ◽  
Shadow Imaging ◽  
Laboratory Modelling ◽  
The Waves

Hydro/aerodynamic laboratory experiment aimed at the laboratory modelling of the physical processes marine atmospheric boundary layer is one of the most complicated. Especial features as spray of droplets, the bubbles in the water and foam generated during the breaking of the waves should be taken into account when modelling extreme weather conditions caused by severe winds. Thus, in the experiment we are dealing with a multiphase turbulent flow with a free boundary. This investigation describes developing approaches to the use of optical methods based on visualization for performing these investigations. Presented results were obtained in experiments carried out on wind-wave facilities. To study the processes of fragmentation of the water surface leading to the formation of droplets and foam, high-speed multi-angle video taking is used in combination with the shadow imaging method.

Measurements of Diffraction of Shock Waves and Resulting Loading of Structures

1950 ◽  
Vol 17 (4) ◽  
pp. 439-445 ◽  
Author(s):  
Walker Bleakney ◽  
D. R. White ◽  
W. C. Griffith
Keyword(s):  
Fluid Dynamics ◽  
High Speed ◽  
Practical Importance ◽  
Fluid Flows ◽  
Optical Methods ◽  
High Speed Flow ◽  
Solid Objects ◽  
Speed Flow ◽  
Transient Interactions ◽  
Methods Of Measurement

Abstract Although the idea of using a shock tube to generate waves of large amplitude and to study their properties is not new, nevertheless this technique has been improved greatly in recent years. This circumstance, taken together with good optical methods of measurement, has provided a powerful tool for the investigation of a great variety of problems in transient interactions of shocks and fluid flows with solid objects and with each other. This paper is concerned with the evolution in time of a flow pattern about an obstacle initially in still air, passed over by a sudden front of high-speed flow induced by a shock wave, the stream approaching a steady configuration. Such information is not only of interest in the theory of fluid dynamics but it also is of considerable practical importance, since the principal forces on the obstacle can be measured as a function of time, and the character of the loading determined. The main objective of this paper is to elucidate the method by giving examples of a great variety of experiments and at the same time to provide a large amount of basic data which may be used by others in various types of analyses.

Sign in / Sign up

Export Citation Format

Share Document