scholarly journals THE RESEARCH OF IGNITION AND COMBUSTION OF ALUMINUM AND MAGNESIUM ALLOYS IN THE PRODUCTS OF DECOMPOSITION OF SOLID PYROTECHNICAL FUELS

2020 ◽  
Vol 1 (2) ◽  
pp. 81-85
Author(s):  
R Motrichuk ◽  
O Kyrychenko ◽  
O Dibrova ◽  
V Vashchenko ◽  
S Kolinko
Keyword(s):  
High Temperature ◽  
Magnesium Alloys ◽  
Fire Hazard ◽  
Combustion Process ◽  
Combustion Products ◽  
Temperature Combustion ◽  
Pyrotechnic Mixtures ◽  
Aluminum Magnesium Alloys ◽  
Ignition And Combustion ◽  
Aluminum And Magnesium Alloys

The results of experimental research of processes of ignition and combustion of particles of aluminum and magnesium alloys in gaseous purges of high-temperature decomposition of solid pyrotechnic fuels leading to their fire explosive hazardous development are presented. The relevance of these research is due to the wide scope of application of pyrotechnic products based on pyrotechnic mixtures of powders of aluminum-magnesium alloys with additives of organic substances, in particular applications in military technology and use in various industries related to the rotation of solid pyrotechnic equipment. Accordingly, in case of fire at facilities where pyrotechnic products are kept or during their transportation there exists the risk of ignition of pyrotechnic mixtures with different acceleration of their subsequent combustion process and destruction of the pyrotechnic products. As a result, high-temperature combustion products are formed, which are fire hazardous to the surrounding environment. Based on the foregoing, it is necessary to obtain data on the regularities of ignition and combustion particles of aluminum-magnesium alloys, which determines the ability to predict the properties of fire hazard pyrotechnic mixtures.  As a result of conducted research, data on the ignition and combustion of particles of aluminum-magnesium alloys was obtained, in particular, the dependence of the delay time of the particles of aluminum-magnesium alloys on their chemical composition was obtained, the data on the process of combustion of particles of aluminum-magnesium alloys was obtained, the data on the effect of additives to aluminum-magnesium alloys was obtained.

scholarly journals Двухканальный лазерный монитор для наблюдения процессов высокотемпературного горения нанопорошков металлов

2021 ◽  
Vol 47 (7) ◽  
pp. 38
Author(s):  
Ф.А. Губарев ◽  
А.В. Мостовщиков ◽  
А.П. Ильин ◽  
Л. Ли ◽  
А.И. Федоров ◽  
...  
Keyword(s):  
High Temperature ◽  
Experimental Technique ◽  
Image Acquisition ◽  
Combustion Process ◽  
Combustion Products ◽  
The Other ◽  
Powder Materials ◽  
Digital Cameras ◽  
Temperature Combustion ◽  
High Temperature Combustion

A laser monitor with two image acquisition channels based on two brightness amplifiers and two digital cameras is presented. The laser monitor makes it possible to visualize the surface of metal nanopowders during combustion simultaneously in two regions of the sample or in one region with different magnifications. The delay between the radiation pulses of the brightness amplifiers is set in such a way that the radiation of one brightness amplifier does not affect the image formed by the other brightness amplifier. The proposed experimental technique makes it possible to study the surface of samples of powder materials during high-temperature combustion, accompanied by intense glowing and scattering of combustion products. The use of two-channel visualization makes it possible to study the surface of a burning sample in more detail, in particular, to study the inhomogeneity of the combustion process.

scholarly journals LASER SYSTEM FOR STUDYING THE DYNAMICS OF HIGH TEMPERATURE COMBUSTION

2019 ◽  
Vol 4 (2) ◽  
pp. 154-162
Author(s):  
Lin Li ◽  
Fedor Gubarev ◽  
Andrei Mostovshchikov ◽  
Alexander Ilyin
Keyword(s):  
High Temperature ◽  
Narrow Band ◽  
Laser System ◽  
Combustion Process ◽  
Visual Observation ◽  
Copper Bromide ◽  
Temperature Combustion ◽  
Temporal And Spatial ◽  
Combustion Processes ◽  
High Temperature Combustion

The paper is devoted to development of methods for studying the dynamics of high-temperature combustion of aluminum nanopowder.The difficulty in studying the combustion of nanopowders is the high temperature and intensity of light emissionduring the combustion process, which makes the visual observation virtually impossible.The paper discusses various schemes using laser radiation to study the combustion processes of metal nanopowders.Particular mentions the use of the laser monitor based on an active medium on copper bromide vapor to study the combustion process of various powders and mixtures.The laser monitor combines the functions of the narrow-band laser illuminator and the brightness amplifier, thereby achieving the visualization at a narrow gain wavelength. Therefore, the laser monitor can be used to observe the changes in the surface of a burning sample with high temporal and spatial resolution.

scholarly journals Features of thermodynamic and thermal processes in hydrogen combustion units and systems on their basis

2021 ◽  
Vol 2039 (1) ◽  
pp. 012032
Author(s):  
A I Schastlivtsev ◽  
V I Borzenko
Keyword(s):  
High Temperature ◽  
Combustion Products ◽  
Hydrogen Combustion ◽  
Thermal Processes ◽  
Steam Generators ◽  
Temperature Combustion ◽  
Main Components ◽  
High Temperature Combustion

Abstract The main types and designs of hydrogen combustion units (HCU), including hydrogen-oxygen steam generators, superheaters and air heaters of various power levels, are considered. The main problems arising in the development, creation and testing of such installations are determined, including the problems of cooling the most heat-stressed units, mixing of the main components of the fuel and oxidizer, mixing of high-temperature combustion products and ballasting components, problems associated with the completeness of hydrogen combustion and ensuring safety during operation.

The Combustion Characteristics of n-Heptane Fueled HCCI Engine Operation With Gaseous Fuels Admission

2006 ◽  
Author(s):  
C. Liu ◽  
G. A. Karim ◽  
A. Sohrabi ◽  
F. Xiao
Keyword(s):  
Carbon Monoxide ◽  
High Temperature ◽  
Combustion Process ◽  
Cylinder Pressure ◽  
Engine Operation ◽  
Hcci Engine ◽  
Gaseous Fuels ◽  
High Temperature Reaction ◽  
Temperature Combustion ◽  
Combustion Region

The effects of the introduction of the gaseous fuels, methane, hydrogen and carbon monoxide into the intake of a variable compression ratio n-heptane fuelled HCCI, CFR engine were investigated. The variations in some of the key combustion and operational parameters were determined experimentally. These included cylinder pressure and its rise rate temporal developments, autoignition timing, combustion durations for both the low and high temperature reaction regions, COV values for IMEP and maximum cylinder pressure, and the incidence of knock and its intensity. In parallel with the experimental investigation, results of a numerical simulation of the processes involved obtained by employing a KIVA based approach while incorporating sufficiently detailed chemical kinetics are presented. It was found that supplementing n-heptane HCCI with gaseous fuels could inhibit the low temperature combustion region and delay to varying extents the high temperature combustion region. Methane admission produced lengthening of the delay to autoignition and extended the combustion durations. It is suggested that supplementing the liquid fuel with methane may be a means for controlling the combustion process of a liquid fuelled HCCI engine while obtaining higher power and acceptable levels of emissions without producing unacceptably heavy knock. However, the addition of hydrogen or carbon monoxide could not reduce the intensity of knock while improving power output.

Effect of oxidative torrefaction on high temperature combustion process of wood sphere

Fuel ◽  
2021 ◽  
Vol 286 ◽  
pp. 119379
Author(s):  
Xin Li ◽  
Zhimin Lu ◽  
Jinzheng Chen ◽  
Xiaoxuan Chen ◽  
Yuan Jiang ◽  
...  
Keyword(s):  
High Temperature ◽  
Combustion Process ◽  
Temperature Combustion ◽  
High Temperature Combustion

Measurement Of Interfacial Segregation In Aluminum-Magnesium Alloys Using A Feg-Tem And Eds

1999 ◽  
Vol 5 (S2) ◽  
pp. 160-161
Author(s):  
J.S. Vetrano ◽  
C.H. Henager
Keyword(s):  
High Temperature ◽  
Magnesium Alloys ◽  
Superplastic Forming ◽  
Automotive Applications ◽  
Automotive Components ◽  
Intermetallic Particles ◽  
Interfacial Segregation ◽  
Aluminum Magnesium Alloys ◽  
Viable Method ◽  
Primary Problem

Aluminum-magnesium alloys are currently being utilized in lightweight automotive components and their good strength and weldability characteristics has made them candidates for increased use. The primary problem with using aluminum alloys for automotive applications is their relatively low formability. Superplastic forming (SPF) is a viable method for producing high elongations and is enabled in these alloys by the manipulation of intermetallic particles (e.g. Al3Sc) that restrict grain growth at the high homologous temperatures necessary for this technique [1]. SPF of Al-Mg-Mn-Sc alloy has yielded elongations of over 600% [2]. However, Al3Sc particles age rapidly at high temperatures which can reduce their strengthening characteristics following deformation. It has been experimentally observed that the addition of Zr to Al-Sc alloys retards the aging of the Al3Sc precipitates [3]. This is beneficial for high temperature conditions like superplastic forming and welding. In this study we examine the location of Zr in the strupturc and how it may be inhibiting particle aging.

scholarly journals Simultaneous High-Speed Formaldehyde PLIF and Schlieren Imaging of Multiple Injections From an ECN Spray D Injector

2020 ◽  
Author(s):  
Noud Maes ◽  
Hyung Sub Sim ◽  
Lukas Weiss ◽  
Lyle Pickett
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Combustion Products ◽  
Schlieren Imaging ◽  
Multiple Injections ◽  
Soot Precursors ◽  
Planar Laser ◽  
Temperature Combustion ◽  
Polycyclic Aromatic ◽  
High Temperature Combustion

Abstract The interaction of multiple injections in a diesel engine facilitates a complex interplay between freshly introduced fuel, previous combustion products, and overall combustion. To improve understanding of the relevant processes, high-speed Planar Laser-Induced Fluorescence (PLIF) with 355-nm excitation of formaldehyde and Polycyclic Aromatic Hydrocarbon (PAH) soot precursors is applied to multiple injections of n-dodecane from Engine Combustion Network Spray D, characterized by a converging 189-μm nozzle. High-speed schlieren imaging is applied simultaneously with 50-kHz PLIF excitation to visualize the spray structures, jet penetration, and ignition processes. For the first injection, formaldehyde (as an indicator of low-temperature chemistry) is first found in the jet periphery, after which it quickly propagates through the center of the jet, towards the jet head prior to high-temperature ignition. At second-stage ignition, downstream formaldehyde is consumed rapidly and upstream formaldehyde develops into a quasi-steady structure for as long as the momentum flux from the injector continues. Since the first injection in this work is relatively short, differences to a single long injection are readily observed, ultimately resulting in high-temperature combustion and PAH structures appearing farther upstream after the end of injection. For the second injection in this work, the first formaldehyde signal is significantly advanced because of the entrained high-temperature combustion products, and an obvious premixed burn event does not occur. The propensity for combustion recession after the end of the first injection changes significantly with ambient temperature, thereby affecting the level of interaction between the first- and second injection.

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