scholarly journals Experimental Investigation on the Influence of Target Physical Properties on an Impinging Plasma Jet

Plasma ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Emanuele Simoncelli ◽  
Augusto Stancampiano ◽  
Marco Boselli ◽  
Matteo Gherardi ◽  
Vittorio Colombo
Keyword(s):  
Physical Properties ◽  
High Speed ◽  
Gas Flow ◽  
Light Emission ◽  
Fluid Dynamic ◽  
Imaging Techniques ◽  
Plasma Jet ◽  
Time Behavior ◽  
Charge Coupled Device ◽  
Intensified Charge Coupled Device

The present work aims to investigate the interaction between a plasma jet and targets with different physical properties. Electrical, morphological and fluid-dynamic characterizations were performed on a plasma jet impinging on metal, dielectric and liquid substrates by means of Intensified Charge-Coupled Device (ICCD) and high-speed Schlieren imaging techniques. The results highlight how the light emission of the discharge, its time behavior and morphology, and the plasma-induced turbulence in the flow are affected by the nature of the target. Surprisingly, the liquid target induces the formation of turbulent fronts in the gas flow similar to the metal target, although the dissipated power in the former case is lower than in the latter. On the other hand, the propagation velocity of the turbulent front is independent of the target nature and it is affected only by the working gas flow rate.

Investigation of Auto-Ignition of a Pulsed Methane Jet in Vitiated Air Using High-Speed Imaging Techniques

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
W. Meier ◽  
I. Boxx ◽  
C. Arndt ◽  
M. Gamba ◽  
N. Clemens
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Imaging Techniques ◽  
Frame Rate ◽  
Experimental Arrangement ◽  
Single Shot ◽  
Exhaust Gas ◽  
High Speed Imaging ◽  
Auto Ignition ◽  
Flow Field Characteristics

An experimental arrangement for the investigation of auto-ignition of a pulsed CH4 jet in a coflow of hot exhaust gas from a laminar lean premixed H2/air flame at atmospheric pressure is presented. The ignition events were captured by high-speed imaging of the OH∗ chemiluminescence associated with the igniting flame kernels at a frame rate of 5 kHz. The flow-field characteristics were determined by high-speed particle image velocimetry and Schlieren images. Furthermore, high-speed imaging of laser-induced fluorescence of OH was applied to visualize the exhaust gas flow and the ignition events. Auto-ignition was observed to occur at the periphery of the CH4 jet with high reproducibility in different runs concerning time and location. In each measurement run, several hundred consecutive single shot images were recorded from which sample images are presented. The main goals of the study are the presentation of the experimental arrangement and the high-speed measuring systems and a characterization of the auto-ignition events occurring in this system.

Optical Restriction of Plasma Emission Light for Nanometric Sampling Depth and Depth Profiling of Multilayered Metal Samples

2007 ◽  
Vol 61 (7) ◽  
pp. 719-724 ◽  
Author(s):  
T. Čtvrtníčková ◽  
F. J. Fortes ◽  
L. M. Cabalín ◽  
J. J. Laserna
Keyword(s):  
Light Emission ◽  
Depth Profiling ◽  
Depth Resolution ◽  
Homogeneous Distribution ◽  
Charge Coupled Device ◽  
Depth Analysis ◽  
Delay Times ◽  
Laser Induced Breakdown ◽  
Intensified Charge Coupled Device ◽  
Emission Light

Improvement in depth profiling capabilities of laser-induced breakdown spectrometry (LIBS) for multilayered samples has been attempted. For this purpose, in a typical LIBS experiment, an optical restriction consisting of a pinhole placed between the dichroic mirror and the collecting lenses has been used. This new optical approach allows observing only the light emission coming from the central region of the plume. The microplasma was created on the sample by a pulsed Nd:YAG laser operating at 1064 nm with a homogeneous distribution of energy across the beam. Light emitted by the microplasma was detected with an intensified charge-coupled device (iCCD) multichannel detector. The effect of pinhole diameter and the delay time influence on depth analysis have been assessed. An ablation range of only a few nanometers per pulse has been achieved. Depth profiles of various metals (Cr, Ni, Cu) from multilayered samples have been generated by LIBS and depth resolution at different delay times using various pinhole diameters have been calculated and compared.

Investigation of Auto-Ignition of a Pulsed Methane Jet in Vitiated Air Using High-Speed Imaging Techniques

2010 ◽  
Author(s):  
Wolfgang Meier ◽  
Isaac Boxx ◽  
Christoph Arndt ◽  
Mirko Gamba ◽  
Noel Clemens
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Imaging Techniques ◽  
Frame Rate ◽  
Experimental Arrangement ◽  
Single Shot ◽  
Exhaust Gas ◽  
High Speed Imaging ◽  
Auto Ignition ◽  
Flow Field Characteristics

An experimental arrangement for the investigation of auto-ignition of a pulsed CH4 jet in a co-flow of hot exhaust gas from a laminar lean premixed H2/air flame at atmospheric pressure is presented. The ignition events were captured by high-speed imaging of the OH* chemiluminescence associated with the igniting flame kernels at a frame rate of 5 kHz. The flow field characteristics were determined by high-speed PIV and Schlieren images. Further, high-speed imaging of laser-induced fluorescence of OH was applied to visualize the exhaust gas flow and the ignition events. Auto-ignition was observed to occur at the periphery of the CH4 jet with high reproducibility in different runs concerning time and location. In each measurement run several hundred consecutive single shot images were recorded from which sample images are presented. The main goals of the study are the presentation of the experimental arrangement and the high-speed measuring systems and a characterization of the auto-ignition events occurring in this system.

Characteristics of Flame Modes for a Conical Bluff Body Burner With a Central Fuel Jet

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Haojie Tang ◽  
Dong Yang ◽  
Tongfeng Zhang ◽  
Min Zhu
Keyword(s):  
High Speed ◽  
Bluff Body ◽  
Recirculation Zone ◽  
Particle Image ◽  
Reynolds Numbers ◽  
Charge Coupled Device ◽  
Fuel Jet ◽  
Image Velocimetry ◽  
Intensified Charge Coupled Device ◽  
Turbulent Air Flow

Bluff body stabilized nonpremixed flames are usually used as pilot flames in lean-premixed combustors. Experiments are conducted to investigate the characteristics of the flame. Typical flame modes are investigated in both stable and unstable conditions. The flow structures, the reaction zone, and the dynamics of unstable flames are measured with particle image velocimetry (PIV), intensified charge-coupled device (ICCD) and a high-speed camera, respectively, based on which the inherent mechanisms that influence the configuration and stabilization of the flame are analyzed. Stable flames are apparently influenced by the mixing characteristics in the recirculation zone. Flame detachment, a typical phenomenon of stable flames in a turbulent air flow, can be explained by the distribution of fuel concentration in the recirculation zone. The Reynolds number of air has different effects on different parts of the flame, which results in three unstable flame modes at different Reynolds numbers of air. These results could be helpful for the design of stable burners in practice.

A Novel Optical System for Investigation on the Characteristics of Light Emission from Long Plasma Column

2012 ◽  
Vol 220-223 ◽  
pp. 2047-2051
Author(s):  
Xue Chen Li ◽  
Peng Ying Jia
Keyword(s):  
Optical System ◽  
Plasma Column ◽  
Barrier Discharge ◽  
Light Emission ◽  
Time Lag ◽  
Half Cycle ◽  
Charge Coupled Device ◽  
Emission Signal ◽  
Breakdown Mechanism ◽  
Intensified Charge Coupled Device

Although intensified charge coupled device (ICCD) is conventionally used to investigate the breakdown mechanism in gas discharge. ICCD can not be used to study the long plasma column because it is hard to be imaged. For solving this problem, a novel optical system is proposed which consists of several elements. Each element is composed of one collimator and a photomultiplier tube. Using this system, spatial resolved emission signal can be obtained. Results show that the light emission signal from each area shows a pulse with a width of about 3μs. It is interesting that the time lag in each half cycle increases with the increase of distance away from the dielectric barrier discharge (DBD). This phenomenon implies that the plasma bullet always leaves DBD at the rising edge of the applied voltage. The time lag versus the distance from DBD is used to calculate the propagation velocity of the discharge.

UNS C36000

Alloy Digest ◽  
1988 ◽  
Vol 37 (3) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Speed ◽  
Heat Treating ◽  
Screw Machine ◽  
Trade Names ◽  
Machine Work

Abstract UNS NO. C36000 is a leaded brass suitable for high-speed screw-machine work. It has many uses such as hardware, gears and pinions. Its trade names include free-turning brass, free-cutting yellow brass and high-leaded brass. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-536. Producer or source: Brass mills.

ANACONDA ALLOY 360

Alloy Digest ◽  
1982 ◽  
Vol 31 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
High Speed ◽  
Heat Treating ◽  
High Speed Machining ◽  
Copper Base ◽  
Screw Machine ◽  
Medium Strength ◽  
Machining Operations ◽  
Strength And Ductility

Abstract ANACONDA Alloy 360 is a leaded brass and is the alloy most often used for high-speed machining operations; it fills most of the needs for such purposes. Alloy 360 is the standard free-cutting brass and its machinability has become the standard by which all other copper-base alloys are rated. It has medium strength and ductility. Alloy 360 is used for hardware such as gears and pinions where excellent machinability is of prime importance and for all types of automatic high-speed screw-machine products. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-447. Producer or source: Anaconda American Brass Company.

ENPLATE NI-423

Alloy Digest ◽  
1986 ◽  
Vol 35 (11) ◽  
Keyword(s):  
Wear Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
High Speed ◽  
Chemical Reduction ◽  
Electronic Devices ◽  
Electroless Nickel ◽  
Heat Treating ◽  
Corrosion And Wear ◽  
Phosphorus Alloy

Abstract ENPLATE NI-423 is a nickel-phosphorus alloy deposited by chemical reduction without electric current. It is deposited by a stable, relatively high-speed functional electroless nickel process that produces a low-stress coating with good ductility and excellent resistance to corrosion. Its many uses include equipment for chemicals and food, aerospace components, molds and electronic devices. This datasheet provides information on composition, physical properties, and hardness. It also includes information on corrosion and wear resistance as well as heat treating, machining, joining, and surface treatment. Filing Code: Ni-343. Producer or source: Enthone Inc..

ALX ALLOY

Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Speed ◽  
Heat Treating ◽  
Temperature Performance ◽  
Cobalt Base

Abstract ALX is a composition of nonferrous materials with a cobalt base containing chromium, tungsten and carbon. This alloy is commonly supplied in the cast-to-shape form, having an as-cast hardness of Rockwell C60-62 and requiring no further heat treatment. ALX is also supplied as cast tool bit material and is useful where conventional high-speed steels or carbides do not function effectively. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting, forming, heat treating, and machining. Filing Code: Co-35. Producer or source: Allegheny Ludlum Corporation.

MUSTANG-LC

Alloy Digest ◽  
1967 ◽  
Vol 16 (4) ◽  
Keyword(s):  
Physical Properties ◽  
High Speed ◽  
High Speed Steel ◽  
Hot Extrusion ◽  
Heat Treating ◽  
Hot Forming ◽  
Steel Company ◽  
Extrusion Dies ◽  
Die Life

Abstract Mustang-LC is a tungsten-molybdenum high-speed steel specially developed for hot work applications requiring long die life. It is recommended for hot forming and swaging dies, hot extrusion dies, hot punches, etc. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-192. Producer or source: Jessop Steel Company.

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