High-speed colour cinematography of the spontaneous ignition of propane–air and n-pentane–air mixtures

2011 ◽  
Vol 21 (1) ◽  
pp. 31-33 ◽  
Author(s):  
Nikolai M. Rubtsov ◽  
Boris S. Seplyarskii ◽  
Kirill Ya. Troshin ◽  
Georgii I. Tsvetkov ◽  
Victor I. Chernysh
Keyword(s):  
High Speed ◽  
Spontaneous Ignition

Fuel Systems Problems in High Speed Aircraft

1964 ◽  
Vol 68 (637) ◽  
pp. 11-24 ◽  
Author(s):  
W. G. Lydiard
Keyword(s):  
High Speed ◽  
Test Method ◽  
High Rate ◽  
Spontaneous Ignition ◽  
Engine Control System ◽  
Aircraft Systems ◽  
Acute Form ◽  
Valid Test ◽  
Kinetic Effects ◽  
Aircraft Configurations

SummaryThe lecture discusses the extent to which the problems met in the fuel systems of subsonic aircraft are aggravated by flight at supersonic speeds and mentions some new problems of considerable severity. These arise from the relatively large fuel quantity required, its high rate of consumption and its heating by kinetic effects or by its use as a heat sink for the aircraft systems. The paper includes a discussion on fuel management and gauging and of the means used to transfer fuel to the engines—showing the relative merits of some of the available pumping techniques. A few comments only are made on the engine control system.The problem of thermal degradation of the fuel in the tanks and in components leading to the engine is discussed, with particular attention being paid to the difficulty of establishing a valid test method for differing aircraft configurations.Spontaneous ignition of flammable mixtures in contact with heated surfaces is a hazard that is likely to arise in a particularly acute form at a Mach number of about 3. The progress of research into this phenomenon is briefly outlined, and some of the measures which may be adopted to ensure safety are indicated. Associated with this is the necessity to develop instruments to detect hazardous conditions in various parts of an aircraft, on which some recommendations are made.

Recent Developments in “Knock” Research

1951 ◽  
Vol 5 (1) ◽  
pp. 89-99 ◽  
Author(s):  
D. Downs ◽  
R. W. Wheeler
Keyword(s):  
High Speed ◽  
Spark Ignition Engine ◽  
The Other ◽  
Spontaneous Ignition ◽  
Physical Factors ◽  
Fuel Quality ◽  
Two Stage ◽  
Engine Design ◽  
Recent Developments ◽  
Ratio Speed

Although the importance of “knock” in limiting the power output and efficiency of the spark-ignition engine was realized long ago, and much empirical information has been accumulated which has enabled engine design and fuel quality to be improved—so minimizing the restrictions due to knock—progress in understanding the fundamental nature of the knocking process has been comparatively slow. Recent work, both in Great Britain and America, has improved our knowledge of the chemical and physical factors involved, resulting in a better understanding of the phenomenon. The use of an electromagnetically operated gas sampling valve has enabled the sequence of chemical reactions, occurring in the engine cylinder, prior to knock, to be followed. Organic peroxides have been shown to be some of the most important intermediate products of combustion, and the effect of changing engine conditions—such as compression ratio, speed, and mixture strength—on their formation has been explored. These experiments have shown that there are at least two types of precombustion knock mechanism, one a “low”-temperature two-stage process involving the formation of peroxides, and the other, a “high”-temperature process which is non-peroxidic in character. Studies of the combustion reactions in a motored engine have confirmed these conclusions. So far as the knocking process itself is concerned, there have been two main schools of thought, one that it was an autoignition (i.e., spontaneous ignition) pure and simple and the other that it was a detonation wave perhaps preceded by autoignition. In reviewing published work, the authors consider that the bulk of the evidence favours the autoignition theory. An alternative explanation of the N.A.C.A. high-speed photographic work is put forward which would appear to support the conception of a two-stage autoignition.

Spontaneous Ignition Testing for High Speed Aircraft

2009 ◽  
pp. 150-150-19
Author(s):  
W. F. Hamilton ◽  
R. A. Holloway
Keyword(s):  
High Speed ◽  
Spontaneous Ignition

Investigation into Spontaneous Ignition of Hydrogen–air Mixtures in a Heated Reactor at Atmospheric Pressure by High-speed Cinematography

2012 ◽  
Vol 22 (4) ◽  
pp. 222-224 ◽  
Author(s):  
Nikolai M. Rubtsov ◽  
Boris S. Seplyarskii ◽  
Kirill Ya. Troshin ◽  
Victor I. Chernysh ◽  
Georgii I. Tsvetkov
Keyword(s):  
Atmospheric Pressure ◽  
High Speed ◽  
Spontaneous Ignition ◽  
High Speed Cinematography

Characteristics of Spontaneous Ignition and Combustion in Unsteady High-Speed Gaseous Fuel Jets

2003 ◽  
Author(s):  
Takuji Ishiyama ◽  
Masahiro Shioji ◽  
Tadayoshi Ihara ◽  
Takanori Inoue ◽  
Noriyuki Takada
Keyword(s):  
High Speed ◽  
Gaseous Fuel ◽  
Spontaneous Ignition ◽  
Ignition And Combustion

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

The on-line use of histogram data for high-speed correction and alignment of electron microscope images

1984 ◽  
Vol 42 ◽  
pp. 556-557
Author(s):  
William Krakow
Keyword(s):  
Power Spectrum ◽  
High Speed ◽  
Direct Memory Access ◽  
Digital Television ◽  
Contrast Transfer Function ◽  
The Past ◽  
High Resolution Tem ◽  
On Line ◽  
Correction Of Astigmatism ◽  
The Fourier Transform

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

An atomic-resolution microscope study of Al contracts on GaAs

1986 ◽  
Vol 44 ◽  
pp. 726-727
Author(s):  
Z. Liliental-Weber ◽  
C. Nelson ◽  
R. Ludeke ◽  
R. Gronsky ◽  
J. Washburn
Keyword(s):  
High Speed ◽  
Schottky Contacts ◽  
Detailed Knowledge ◽  
The Past ◽  
Semiconductor Interfaces ◽  
Deposited Metal ◽  
Microwave Applications ◽  
Free Interfaces ◽  
Potential Use

The properties of metal/semiconductor interfaces have received considerable attention over the past few years, and the Al/GaAs system is of special interest because of its potential use in high-speed logic integrated optics, and microwave applications. For such materials a detailed knowledge of the geometric and electronic structure of the interface is fundamental to an understanding of the electrical properties of the contact. It is well known that the properties of Schottky contacts are established within a few atomic layers of the deposited metal. Therefore surface contamination can play a significant role. A method for fabricating contamination-free interfaces is absolutely necessary for reproducible properties, and molecularbeam epitaxy (MBE) offers such advantages for in-situ metal deposition under UHV conditions

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