Evaluation of Stored Energy in Ultrafine Aluminum Powder Produced by Plasma Explosion

1999 ◽  
Vol 15 (6) ◽  
pp. 794-800 ◽  
Author(s):  
Jonathan T. DeSena ◽  
Kenneth K. Kuo
Keyword(s):  
Aluminum Powder ◽  
Stored Energy ◽  
Ultrafine Aluminum ◽  
Ultrafine Aluminum Powder

Propellant grade ultrafine aluminum powder by RF induction plasma

2018 ◽  
Vol 29 (3) ◽  
pp. 804-812 ◽  
Author(s):  
P. Sai Karthik ◽  
S.B. Chandrasekhar ◽  
D. Chakravarty ◽  
P.V.V. Srinivas ◽  
V.S.K. Chakravadhanula ◽  
...  
Keyword(s):  
Aluminum Powder ◽  
Induction Plasma ◽  
Ultrafine Aluminum ◽  
Ultrafine Aluminum Powder ◽  
Rf Induction Plasma

scholarly journals INFLUENCE OF POROSITY OF PRESSED SAMPLES OF SUPERFINE ALUMINUM POWDER ON COMBUSTION PARAMETERS

2021 ◽  
pp. 199-205
Author(s):  
В.О. Попов ◽  
В.Н. Комов ◽  
Е.М. Попенко ◽  
А.В. Сергиенко
Keyword(s):  
Aluminum Powder ◽  
Gas Permeability ◽  
Side Surface ◽  
Combustion Mechanism ◽  
Refractory Materials ◽  
Second Stage ◽  
Nitride Formation ◽  
Ultrafine Aluminum ◽  
Ultrafine Aluminum Powder ◽  
Two Stages

Данная статья посвящена исследованию влияния пористости прессованных таблеток из сверхтонкого порошка алюминия (СТП Al). Определен механизм горения, протекающий в две стадии: первая, медленная, включающая в себя как «кольцевое» горение боковой поверхности, так и параллельное горение концентрическими слоями, вторая стадия объемная, сопровождающаяся резким самопроизвольным увеличением температуры горения и интенсивности свечения. Показано, что увеличение плотности упаковки СТП Al позволяет замедлить процесс окисления алюминия более чем в два раза. Это обусловлено снижением газопроницаемости таблетки и затруднением доступа воздуха вглубь образца. Повышение пористости материала позволяет регулировать процесс нитридообразования за счёт увеличения содержания азота в продуктах при фильтрационном механизме горения, что открывает возможности получения тугоплавких материалов. This article is devoted to the study of the effect of porosity of compressed tablets from ultrafine aluminum powder (STP Al). The combustion mechanism was determined, which proceeds in two stages: the first, slow, which includes both "ring" combustion of the side surface and parallel combustion with concentric layers, the second stage is volumetric, accompanied by a sharp spontaneous increase in the combustion temperature and glow intensity. It has been shown that an increase in the packing density of HFC Al makes it possible to slow down the process of aluminum oxidation by more than two times. This is due to a decrease in the gas permeability of the tablet and the difficulty of air access deep into the sample. An increase in the porosity of the material makes it possible to regulate the process of nitride formation by increasing the nitrogen content in the products during the filtration mechanism of combustion, which opens up the possibility of obtaining refractory materials.

INFLUENCE OF FLOW SWIRLING ON COMBUSTION OF ALUMINUM POWDER AEROSUSPENSION IN A CHAMBER WITH EXTENSION

2020 ◽  
Author(s):  
A. Yu. Krainov ◽  
◽  
K. M. Moiseeva ◽  
V. A. Poryazov ◽  
◽  
...  
Keyword(s):  
Dynamic Model ◽  
Aluminum Powder ◽  
Swirling Flow ◽  
Numerical Study ◽  
Mathematical Formulation ◽  
Expansion Chamber ◽  
Flow Swirling ◽  
Air Suspension

A numerical study of combustion of the aluminum-air suspension in the swirling flow in the expansion chamber has been performed. The physical and mathematical formulation of the problem is based on the dynamic model of the multiphase reacting media.

The Energy of the Electrostatic Field

2020 ◽  
Vol 67 (1) ◽  
pp. 35-41
Author(s):  
Igor’ P. Popov
Keyword(s):  
Electrostatic Field ◽  
Energy System ◽  
Electrostatic Energy ◽  
Research Purpose ◽  
Target System ◽  
Mathematical Form ◽  
Stored Energy ◽  
Energy Materials ◽  
Modeling And Analysis ◽  
Maximum Work

The work is actual due to the increased role of electrostatic energy in connection with the beginning of mass production of ionistors used in the power supply system of electric vehicles, and the need for the development of theoretical support. (Research purpose) The research purpose is in increasing the correctness of electrostatic calculations that exclude the possibility of obtaining unreliable results in the form of infinite electrostatic energy. (Materials and methods) Authors have used methods of mathematical modeling and analysis, studied the mathematical model as the equivalent of an object that reflects in mathematical form its most important properties, such as the laws that it obeys, and the relationships inherent in its constituent parts. (Results and discussion) Authors have studied the electrostatic field created by a system of two charges of the same name or different names. The article presents calculations for charges located in bodies that have the shape of balls. It was found that the results could be generalized to any form of charged objects. They gave three definitions: first, the total stored energy is the energy of the system or object, equal to the maximum work that the system or object can do if it is given such an opportunity. Second, the conditional realized stored energy is a part of the total stored energy of the system or object, equal to the work that the system or object can produce, limited by a condition that excludes the possibility of the system or object performing the maximum work that the system or object can hypothetically perform. The third is a conditional impossible reserved energy as a part of a complete stored energy system or an object that is equal to the work system or object can do and limited by the condition, which excludes the possibility of making a system or object maximum work that target system or object could hypothetically do. Five theorems were proved. (Conclusions) It was found that the main drawback of the actual potential energy formula is an infinitely large increase in energy at radius tending to 0. The obtained formulas for stored electrostatic energy are devoid of this drawback.

Technology for producing composite nanostructured powder for protective coatings

2020 ◽  
pp. 97-103
Author(s):  
E. Yu. Geraschenkova ◽  
A. F. Vasiliev ◽  
E. A. Samodelkin ◽  
B. V. Farmakovsky
Keyword(s):  
Aluminum Powder ◽  
High Speed ◽  
Protective Coatings ◽  
Hadfield Steel ◽  
Nanostructured Powder ◽  
Powder Composition ◽  
Clad Powder

This article presents the results of the development of technology for producing clad powder and coatings based on it. The possibility of obtaining a clad powder using high-speed mechanosynthesis in disintegrator plants is shown on the example of the Hadfield steel – aluminum powder composition.

scholarly journals Dynamics of the Ice-Crushing Process

1988 ◽  
Vol 34 (118) ◽  
pp. 318-326 ◽  
Author(s):  
Ian J. Jordaan ◽  
Garry W. Timco
Keyword(s):  
Ice Sheet ◽  
Load Cycle ◽  
Stored Energy ◽  
Indentation Process ◽  
Ice Particles ◽  
Mode Of Failure ◽  
Indentation Tests ◽  
Energy Exchanges ◽  
The Mean ◽  
Crushed Ice

Abstract During fast indentation tests on ice sheets at constant rates, crushing is commonly observed at appropriate combinations of speed and aspect ratio. An analysis is made of this mode of failure, using as a basis a recently conducted test on an ice sheet under controlled conditions. The variation of load with time is given special attention, and cyclic variation of load is associated with periodic crushing (pulverization) events, followed by clearing of the crushed ice particles. An analysis of the clearing process is summarized in the paper, treating the crushed ice as a viscous material. A detailed analysis of the energy exchanges during the indentation process is given. Elastic variations of stored energy in the indenter and in the ice sheet are calculated; these are relatively minor. The dissipation of energy during a typical load cycle (3 mm movement during 0.05 s) is about 8 J. The energy required to create surfaces of the crushed ice particles is small (0.006 J), as is the work of crushing based on mechanical testing (0.09 J). It is concluded that the process of viscous extrusion of crushed ice is the main seat of energy dissipation, basically as a frictional process. A relationship for the mean thickness of the crushed ice layer is developed, based on energy-balance considerations.

scholarly journals A Novel Damage Model for Strata Layers and Coal Mass

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1928 ◽  
Author(s):  
Faham Tahmasebinia ◽  
Chengguo Zhang ◽  
Ismet Canbulat ◽  
Samad Sepasgozar ◽  
Serkan Saydam
Keyword(s):  
Constitutive Model ◽  
Strain Energy ◽  
Damage Model ◽  
Rock Joint ◽  
Coal Mass ◽  
Stored Energy ◽  
Rock Interaction ◽  
Geological Factors ◽  
Coal Rock ◽  
Joint Quality

Coal burst occurrences are affected by a range of mining and geological factors. Excessive slipping between the strata layers may release a considerable amount of strain energy, which can be destructive. A competent strata is also more vulnerable to riveting a large amount of strain energy. If the stored energy in the rigid roof reaches a certain level, it will be released suddenly which can create a serious dynamic reaction leading to coal burst incidents. In this paper, a new damage model based on the modified thermomechanical continuum constitutive model in coal mass and the contact layers between the rock and coal mass is proposed. The original continuum constitutive model was initially developed for the cemented granular materials. The application of the modified continuum constitutive model is the key aspect to understand the momentum energy between the coal–rock interactions. The transformed energy between the coal mass and different strata layers will be analytically demonstrated as a function of the rock/joint quality interaction conditions. The failure and post failure in the coal mass and coal–rock joint interaction will be classified by the coal mass crushing, coal–rock interaction damage and fragment reorganisation. The outcomes of this paper will help to forecast the possibility of the coal burst occurrence based on the interaction between the coal mass and the strata layers in a coal mine.

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