Effect of Condensed Phase Particles on the Characteristics of the Electromagnetic Field of Combustion Products in the Flow Duct of a Liquid-Propellant Engine. The Results of Experimental Studies

Experimental studies of the influence of external climatic factors, taking into account exposure, on the change in the bending strength of control and microwave – treated carbon and fiberglass samples in the cured state were performed. An increase in the limit stresses of three – point bending of experimental carbon fiber samples compared to the control ones was found by 7…12 %, and fiberglassby 4…7 %. It is shown that with an increase in exposure to 14 months, the strength of control samples of carbon and fiberglass decreases by an average of 10 %. At the same time, the strength of the prototypes is reduced only by 4.4 %. With an increase in the moisture content of both control and experimental samples, a decrease in their strength is observed. In this case, the linear correlation is average (from– 0.44 to – 0.615). It is established that for experimental samples, the influence of the amount of absorbed moisture on the strength is manifested to a much lesser extent. For carbon fiber, the reduction is 16.6 %, for fiberglass – 12 %.

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Graph-Analytical Estimation Method of Natural Ventilation Efficiency during Natural Gas Combustion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.931.901 ◽

2018 ◽

Vol 931 ◽

pp. 901-904 ◽

Cited By ~ 1

Author(s):

Victor I. Chebotarev ◽

Anastasia P. Pirozhnikova ◽

Alla V. Koroleva

Keyword(s):

Natural Gas ◽

Natural Ventilation ◽

Theoretical Calculations ◽

Residential Buildings ◽

Experimental Studies ◽

Estimation Method ◽

Combustion Products ◽

Gas Combustion ◽

Analytical Estimation ◽

Ventilation Duct

Open burning of natural gas when using gas equipment in the premises of residential buildings is considered, taking into account the formation of combustion products, depending on the coefficients of excess air. Theoretical and experimental studies of combustion processes are presented. To determine the aerodynamic process in the ventilation duct, theoretical calculations of the dependence of the discharge at the entrance to the ventilation duct from the outside temperature of the atmospheric air were made. Graph-analytic method of evaluating the effectiveness of natural ventilation is carried out.

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Dielectric Properties and Substantiation of Electromagnetic Technologies for Oil Sludge Processing

KnE Materials Science ◽

10.18502/kms.v6i1.8140 ◽

2020 ◽

Author(s):

Eldar Rinatovich Abdeev ◽

Minikhan Abuzarovich Fatykhov ◽

Rail Idiatovich Saitov ◽

Rinat Gazizyanovich Abdeev ◽

Lenart Minnehanovich Fatykhov

Keyword(s):

Electromagnetic Field ◽

Dielectric Properties ◽

Atmospheric Oxygen ◽

Experimental Studies ◽

Solid Particles ◽

Oil Sludge ◽

Water Contact ◽

Long Term Storage ◽

Oil Storage ◽

Oil Water

In the process of reception, storage and preparation of oil for processing, significant volumes of oil-containing sludge are formed, which are not only a source of pollution, but also a valuable hydrocarbon feedstock. Long-term storage of oil with water, contact with atmospheric oxygen, and the presence of solid particles hydrophobized with asphalt-resinous and paraffinous substances contribute to the formation of “intermediate layers” in these sludges, which are ultra-stable oil-water emulsions. It is proposed to use the energy of the electromagnetic field of the high and microwave ranges when developing a technology for the destruction of oil-water emulsions. After analyzing the composition of the oil sludge, experimental studies were conducted of the dielectric loss tangenttgδδ of oil with the addition of sand and paraffin, depending on the frequency of electromagnetic oscillations in the range of 30 - 160 MHz and temperature in the range of 25 - 80 ∘ С using the cumeter method. Studies have shown that two technologies for the disposal of oil sludge are possible: HF and UHF methods. To assess the effectiveness of their application, it is necessary to conduct experimental studies of the dielectric properties of oil sludge. Keywords: oil sludge, oil sludge disposal,oil storage, oil-water emulsions, electromagnetic field

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Влияние концентрации капель воды в аэрозольном облаке на скорости их испарения

Письма в журнал технической физики ◽

10.21883/pjtf.2021.22.51723.18791 ◽

2021 ◽

Vol 47 (22) ◽

pp. 28

Author(s):

Р.С. Волков ◽

С.А. Керимбекова ◽

П.А. Стрижак

Keyword(s):

Evaporation Rate ◽

Experimental Studies ◽

Combustion Products ◽

Water Droplets ◽

Variable Parameters ◽

Aerosol Cloud ◽

Integral Characteristics ◽

K Concentration ◽

Mass Evaporation ◽

First Time

The results of experimental studies of the integral characteristics of the water droplets evaporation in aerosol cloud are presented. Variable parameters: initial radius of droplets 0.1–0.25 mm, temperature of combustion products 573–873 K, concentration of water droplets 0.03–0.1 l /m3. The ranges of variation of the water mass evaporation rate are determined depending on the concentration of droplets in the aerosol cloud and their initial sizes. Approximation expressions for the established dependencies are obtained. For the first time, an approach was proposed to determine the evaporation rate of aerosol droplets taking into account the known/calculated values of the evaporation rate of a single drop.

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Microwave solid fuel ignition

Journal of Physics Conference Series ◽

10.1088/1742-6596/2094/5/052054 ◽

2021 ◽

Vol 2094 (5) ◽

pp. 052054

Author(s):

R V Kondratev

Keyword(s):

Electromagnetic Field ◽

Solid Fuel ◽

Thermal Power ◽

Experimental Studies ◽

Chemical Properties ◽

Ignition Process ◽

Boiler Plant ◽

Microwave Exposure ◽

Unburned Fuel ◽

Physical And Chemical

Abstract The article continues the study of the effect of microwave exposure on solid fuel. On the basis of the experimental studies, the dependences of changes in the temperature and humidity fields of the fuel on the time of microwave exposure, to arson, have been established. The possibility of using the microwave electromagnetic field to automate the process of burning solid fuel in a boiler plant, afterburning unburned fuel residues is considered. The mechanism and basic conditions of these processes are presented. The influence of this technology on the intensification of the fuel ignition process, its homogenization, an increase in energy characteristics and a change in the elemental composition, an increase in the efficiency of a boiler plant, a decrease in chemical, mechanical underburning and harmful emissions of a boiler plant is considered. The main conditions of the applied technology are: placement of the microwave generator on the combustion device of the boiler unit, the size of the solid fuel samples or its contacting pieces should be less than the wavelength of the microwave electromagnetic field (12.4 cm), the moisture content - within the range from 10 to 95%. The intensification of the process of burning solid fuel also depends on the type of fuel, its physical and chemical properties (various types of coal, wood fuel, including wood waste, peat, and others). Modernization of boiler plants using this technology is possible by unifying projects that take into account the correspondence of microwave generators to the thermal power of boiler units.

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DEVELOPMENT OF THE ASSESSMENT TECHNIQUE OF THERMAL IMAGING CAMERAS FOR FIREFIGHTERS

Fire Safety ◽

10.32447/20786662.35.2019.07 ◽

2020 ◽

Vol 35 ◽

pp. 41-48

Author(s):

V. Lushch ◽

D. Voitovych ◽

O. Lazarenko ◽

N. Shtangret

Keyword(s):

Thermal Imaging ◽

Experimental Studies ◽

Combustion Products ◽

Toxic Substances ◽

State University ◽

Assessment Technique ◽

Breathing Apparatus ◽

Scientific Task ◽

Subsequent Comparison ◽

Very High

Issues of combating hazardous fire factors such as smoke and heat, which are being fought by the firefighters whit self-contained breathing apparatus (SCBA units) of State Emergency Service of Ukraine, remains one of the complicated tasks which should be solved by the operational units. The concentration of toxic substances in the first minutes of the fire are 12-100 times above the maximum. The average volume temperature in the first 5-10 minutes of fire can reach 140-900 оС. The rate of smoke spreading and toxic substances is very high. Every year, about 16 per 1 million people worldwide die from the cause of poisoning by combustion products during the fire, moreover, this trend is increasing every year. Therefore, the effectiveness of rescuing people, eliminating fires and carrying out rescue operations in the non-breathable environment depends, largely, on the speed of carrying out such operative actions, with the help of technical means one of which is a thermal imaging camera (TIC). As foreign practice shows, firefighters have widely used TICs during firefighting, searching victims and reconnaissance, however, in Ukraine, these devices have only just begun to appear in SES units. Thus, the study of the assessment of the parameters of TICs and their subsequent comparison is an urgent scientific task. The solving of which makes it possible to improve the efficiency of fire elimination during firefighting with zero visibility and a large number of combustion products by the SCBA units. Accordingly, there is a need for developing an assessment technique of the TIC parameters, which ensure the effectiveness of reconnaissance, searching the sources of fire and rescue operations by the SCBA units. The article describes the assessment methodology for estimating the parameters of TICs, according to which will be conducted experimental studies based on the fire module of Lviv State University of Life Safety. The aims of this study will identify the influence of fire environmental on the parameters of the TICs and on the efficiency of the reconnaissance process by the SCBA units in order to detect the fire cell and other issues. After conducting the research, comparative data will be presented that will allow to evaluate and select the most optimal variant of the TICs for the SES of Ukraine.

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MONITORING SYSTEM TO ENSURE THE ELECTROMAGNETIC SAFETY OF HOUSEHOLD OBJECTS

Электросвязь ◽

10.34832/elsv.2020.9.8.012 ◽

2020 ◽

Author(s):

Е.В. ТИТОВ

Keyword(s):

Electromagnetic Field ◽

Field Strength ◽

Electric Field ◽

Electromagnetic Radiation ◽

Electromagnetic Fields ◽

Personal Computer ◽

Experimental Studies ◽

Electromagnetic Environment ◽

Stay Time ◽

Computer Monitors

Предложен метод формирования картин опасности электромагнитных излучений в ограниченном пространстве с источниками электромагнитных полей по критерию допустимого времени пребывания людей. Представлены результаты экспериментальных исследований опасности электромагнитного поля от мониторов персональных компьютеров, оптических манипуляторов типа «мышь» и многофункциональных устройств типа «принтер-копир-сканер». Приведены компьютерные модели электромагнитной обстановки в виде картин распределения напряженности электрического поля на частоте 30 кГц, а также в виде картин опасности электромагнитных излучений по критерию допустимого времени. It is proposed the method of forming pictures of the danger of electromagnetic radiation in a limited space with sources of electromagnetic fields according to the criterion of the allowable stay time. The article shows the results of experimental studies of the electromagnetic field from personal computer monitors, optical mice, and multifunctional devices printer-copier-scanner. Computer models of the electromagnetic environment are presented in the form of pictures of the distribution of the electric field strength at a frequency of 30 kHz

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Change of Rigidity of PCM Modified in an Ultrahigh Frequencies Electromagnetic Field under the Action of External Factors

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1031.234 ◽

2021 ◽

Vol 1031 ◽

pp. 234-241

Author(s):

Irina V. Zlobina

Keyword(s):

Electromagnetic Field ◽

Elastic Modulus ◽

Carbon Fiber ◽

Experimental Studies ◽

External Environment ◽

Carbon Fiber Reinforced Plastic ◽

Fiber Reinforced ◽

Fiber Reinforced Plastic ◽

Reinforced Plastic ◽

Carbon Fiber Reinforced

Experimental studies of bending deformation of carbon - and fiberglass samples after 8-month exposure in full-scale conditions were performed and the modulus of transverse elasticity was determined. It was found that the influence of the external environment on fiberglass samples is more significant. For carbon fiber, there was an average decrease of 7.1%, and for fiberglass-by 14%. Modification of samples in ultrahigh frequencies (UHF) electromagnetic field reduces the negative influence of the environment: the values of the transverse elastic modulus of carbon fiber and fiberglass samples are reduced by 5% and 11%, respectively. It is shown that the UHF electromagnetic field in rational modes can increase the modulus of transverse elasticity of carbon fiber by (27-30)%, fiberglass – by (20.8-25.6)% with a significant increase in the uniformity of this parameter. Experimental studies of the bending deformation of carbon-and fiberglass specimens after 8-month exposure in natural conditions have been carried out, and the shear elastic modulus has been determined. It has been established that the influence of the external environment on fiberglass samples is more significant. For carbon fiber reinforced plastic, a decrease was noted on average by 7.1%, for fiberglass - by 14%. Modification of samples in a microwave electromagnetic field helps to reduce the negative influence of the external environment: the values of the shear modulus of the prototypes of carbon fiber reinforced plastic and fiberglass are reduced by 5% and 11%, respectively. It is shown that the microwave electromagnetic field in rational modes allows increasing the transverse elastic modulus of carbon fiber reinforced plastic by (27-30)%, fiberglass - by (20.8-25.6)% with a significant increase in the uniformity of this parameter.

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