scholarly journals DEVELOPMENT OF A MATHEMATICAL MODEL OF BEHAVIOR OF AIR FLOWS IN THE TERRITORY OF OPEN PORT COAL WAREHOUSES

2020 ◽  
pp. 20-26
Author(s):  
Sergey N. Sikarev Sikarev ◽  
Evgeny I. Adamov ◽  
Sergey G. Smirnov ◽  
Igor V. Lipatov ◽  
Mark M. Lyudmilin
Keyword(s):  
Control Volume ◽  
Coal Dust ◽  
Dust Particles ◽  
Air Masses ◽  
Coal Particles ◽  
Arbitrary Space ◽  
Air Flows ◽  
Meteorological Features ◽  
Volume Method ◽  
Open Port

    The article discusses the need to use mathematical modeling to study the behavior of air flows in the territory of a port open coal warehouse. To study these processes of the interaction of the movement of air masses on the territory of the port with coal particles, the movement of a point volume of air in an arbitrary space of the air flow, which is inextricable, was considered. This approach allows to take into account all meteorological features of blowing more accurately: wind speed, altitude distribution of speeds, flow turbulization, various geometric parameters of the warehouse. As a result of the numerical implementation of this model by the control volume method, we get the opportunity to analyze the structure of the stream flowing around the coal warehouse and draw conclusions about the nature of dust formation, separation of coal dust particles, displacement of coal dust particles.

scholarly journals Development of Environmental Friendly Dust Suppressant Based on the Modification of Soybean Protein Isolate

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 165 ◽  
Author(s):  
Hu Jin ◽  
Wen Nie ◽  
Yansong Zhang ◽  
Hongkun Wang ◽  
Haihan Zhang ◽  
...  
Keyword(s):  
Water Retention ◽  
Soybean Protein ◽  
Coal Dust ◽  
Sodium Dodecyl ◽  
Environmentally Friendly ◽  
Protein Isolate ◽  
Dust Particles ◽  
Dust Suppression ◽  
Soybean Protein Isolate ◽  
Coal Particles

Aiming to further improve the dust suppression performance of the dust suppressant, the present study independently develops a new type of biodegradable environmentally-friendly dust suppressant. Specifically, the naturally occurring biodegradable soybean protein isolate (SPI) is selected as the main material, which is subject to an anionic surfactant, i.e., sodium dodecyl sulfonate (SDS) for modification with the presence of additives including carboxymethylcellulose sodium and methanesiliconic acid sodium. As a result, the SDS-SPI cementing dust suppressant is produced. The present study experimentally tests solutions with eight different dust suppressant concentrations under the same experimental condition, so as to evaluate their dust suppression performances. Key metrics considered include water retention capability, cementing power and dust suppression efficiency. The optimal concentration of dust suppressant solution is determined by collectively comparing these metrics. The experiments indicate that the optimal dust suppressant concentration is 3%, at which level the newly developed environmentally-friendly dust suppressant solution exhibits a decent dust suppression characteristic, with the water retention power reaching its peak level, and the corresponding viscosity being 12.96 mPa·s. This performance can generally meet the requirements imposed by coal mines. The peak efficiency of dust suppression can reach 92.13%. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to analyze the dust suppression mechanism of the developed dust suppressant. It was observed that a dense hardened shell formed on the surface of the pulverized coal particles sprayed with the dust suppressant. There is strong cementation between coal dust particles, and the cementation effect is better. This can effectively inhibit the re-entrainment of coal dust and reduce environmental pollution.

scholarly journals Numerical Study on Infrared Optical Property of Diffuse Coal Particles in Mine Fully Mechanized Working Combined with CFD Method

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Wen-Zheng Wang ◽  
Yan-Ming Wang ◽  
Guo-Qing Shi ◽  
De-Ming Wang
Keyword(s):  
Infrared Radiation ◽  
Numerical Study ◽  
Coal Dust ◽  
Mie Scattering ◽  
Dust Particles ◽  
Dust Transport ◽  
Mine Dust ◽  
Comparison Results ◽  
Coal Particles ◽  
Cfd Method

Coal dust seriously threatens the safety and occupational health of coal mines. Numerical simulation research on the infrared radiation characteristics of diffused coal dust is carried out in fully mechanized working faces based on the optical monitoring problem of dust particles in mine atmospheric environments. The CFD method is applied to obtain the law of dust transport and distribution. Combined with Mie scattering model, the infrared radiation change characteristics and spectral selection of diffused coal dust particles are simulated and analyzed along the working face. The comparison results show the following: the attenuation and scattering characteristics of mine dust particles system are first enhanced, and then they weaken as the distance from dust source increases. The infrared attenuation of mine dust at the center of the vertical cross-section is generally greater than that at the roof and floor in the same location. The dispersion of mine dust directly determines the attenuation contribution of respirable dust to total dust. Moreover, the infrared absorption effect of functional groups in coal causes the infrared attenuation effect of coal dust to have obvious optical selectivity along the roadway, the existing optical “window.”

scholarly journals Numerical Simulation of Intrachamber Processes in the Power Plant

2021 ◽  
Vol 11 (11) ◽  
pp. 4990
Author(s):  
Boris Benderskiy ◽  
Peter Frankovský ◽  
Alena Chernova
Keyword(s):  
Numerical Simulation ◽  
Power Plant ◽  
Flow Structure ◽  
Power Plants ◽  
Control Volume ◽  
Conjugate Problem ◽  
Topological Features ◽  
Gas Dynamic ◽  
Calculation Results ◽  
Volume Method

This paper considers the issues of numerical modeling of nonstationary spatial gas dynamics in the pre-nozzle volume of the combustion chamber of a power plant with a cylindrical slot channel at the power plant of the mass supply surface. The numerical simulation for spatial objects is based on the solution conjugate problem of heat exchange by the control volume method in the open integrated platform for numerical simulation of continuum mechanics problems (openFoam). The calculation results for gas-dynamic and thermal processes in the power plant with a four-nozzle cover are presented. The analysis of gas-dynamic parameters and thermal flows near the nozzle cover, depending on the canal geometry, is given. The topological features of the flow structure and thermophysical parameters near the nozzle cap were studied. For the first time, the transformation of topological features of the flow structure in the pre-nozzle volume at changes in the mass channel’s geometry is revealed, described, and analyzed. The dependence of the Nusselt number in the central point of stagnation on the time of the power plants operation is revealed.

scholarly journals A New Formulation of Maxwell’s Equations

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 868
Author(s):  
Simona Fialová ◽  
František Pochylý
Keyword(s):  
Numerical Methods ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Control Volume ◽  
Control Volume Method ◽  
Integral Forms ◽  
New Formulation ◽  
Electrical Induction ◽  
Volume Method ◽  
Integral Identities

In this paper, new forms of Maxwell’s equations in vector and scalar variants are presented. The new forms are based on the use of Gauss’s theorem for magnetic induction and electrical induction. The equations are formulated in both differential and integral forms. In particular, the new forms of the equations relate to the non-stationary expressions and their integral identities. The indicated methodology enables a thorough analysis of non-stationary boundary conditions on the behavior of electromagnetic fields in multiple continuous regions. It can be used both for qualitative analysis and in numerical methods (control volume method) and optimization. The last Section introduces an application to equations of magnetic fluid in both differential and integral forms.

Numerical prediction of the performance of gas-lubricated spiral groove thrust bearings

1997 ◽  
Vol 211 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Y Yue ◽  
T. A. Stolarski
Keyword(s):  
Control Volume ◽  
Numerical Procedure ◽  
Operating Conditions ◽  
Hydrodynamic Bearings ◽  
Thrust Bearings ◽  
Flow Balance ◽  
Control Volumes ◽  
Volume Method ◽  
Spiral Angle ◽  
Spiral Grooves

The objective of this paper is to develop an accurate numerical procedure for the analysis of nominally flat contacts with spiral grooves lubricated by gases. The numerical procedure, which is based on the control-volume method, enables the solutions of the non-linear Reynolds equation to be obtained without limitation in geometry and operating conditions. Satisfactory flow balance was achieved on the control volumes as well as on the whole boundary and the method was proved to be very accurate. Convergence of the method was quick for any compressibility number. Three types of contact with spiral grooves were analysed. They were hydrodynamic bearings without interior chambers, hydrodynamic bearings with interior chambers and hybrid bearings. The effects of spiral angle, groove geometry (length, depth and width) and compressibility on performances were investigated for all possible designs.

A VGGNet-like approach for classifying and segmenting coal dust particles with overlapping regions

2021 ◽  
Vol 132 ◽  
pp. 103506
Author(s):  
Zheng Wang ◽  
Xu Zheng ◽  
Dongyan Li ◽  
Helin Zhang ◽  
Yi Yang ◽  
...  
Keyword(s):  
Coal Dust ◽  
Dust Particles

COMBUSTION OF A GAS SUSPENSION OF COAL DUST IN A SWIRLING FLOW

2021 ◽  
pp. 139-147
Author(s):  
K.M. Moiseeva ◽  
◽  
A.Yu. Krainov ◽  
E.I. Rozhkova ◽  
◽  
...  
Keyword(s):  
Flow Velocity ◽  
Swirling Flow ◽  
Coal Dust ◽  
Combustion Efficiency ◽  
Dust Particles ◽  
Gas Temperature ◽  
Flow Swirl ◽  
Angular Component ◽  
Air Suspension ◽  
The Impact

Swirling combustion is currently one of the most important engineering problems in physics of combustion. There is a hypothesis on the increase in the combustion efficiency of reacting gas mixtures in combustion chambers with swirling flows, as well as on the increase in the efficiency of fuel combustion devices. In this paper, it is proposed to simulate a swirling flow by taking into account the angular component of the flow velocity. The aim of the study is to determine the effect of the angular component of the flow velocity on the characteristics of the flow and combustion of an air suspension of coal dust in a pipe. The problem is solved in a twodimensional axisymmetric approximation with allowance for a swirling flow. A physical and mathematical model is based on the approaches of the mechanics of multiphase reacting media. A solution method involves the arbitrary discontinuity decay algorithm. The impact of the flow swirl and the size of coal dust particles on the gas temperature distribution along the pipe is determined.

Effect of Periodic Imposed Heat Flux on Three-Dimensional Natural Convection in a Partially Heated Cubical Enclosure

2016 ◽  
Vol 831 ◽  
pp. 83-91
Author(s):  
Lahoucine Belarche ◽  
Btissam Abourida
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Study ◽  
Control Volume ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Cubical Enclosure ◽  
Simplec Algorithm ◽  
Volume Method

The three-dimensional numerical study of natural convection in a cubical enclosure, discretely heated, was carried out in this study. Two heating square sections, similar to the integrated electronic components, are placed on the vertical wall of the enclosure. The imposed heating fluxes vary sinusoidally with time, in phase and in opposition of phase. The temperature of the opposite vertical wall is maintained at a cold uniform temperature and the other walls are adiabatic. The governing equations are solved using Control volume method by SIMPLEC algorithm. The sections dimension ε = D / H and the Rayleigh number Ra were fixed respectively at 0,35 and 106. The average heat transfer and the maximum temperature on the active portions will be examined for a given set of the governing parameters, namely the amplitude of the variable temperatures a and their period τp. The obtained results show significant changes in terms of heat transfer, by proper choice of the heating mode and the governing parameters.

scholarly journals Identification of the Aerosol Types over Athens, Greece: The Influence of Air-Mass Transport

2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
D. G. Kaskaoutis ◽  
P. G. Kosmopoulos ◽  
H. D. Kambezidis ◽  
P. T. Nastos
Keyword(s):  
Winter Season ◽  
Saharan Dust ◽  
Dust Particles ◽  
Hysplit Model ◽  
Air Mass ◽  
Back Trajectories ◽  
Air Masses ◽  
Local Pollution ◽  
Coarse Mode ◽  
Aerosol Types

Aerosol optical depth at 550 nm () and fine-mode (FM) fraction data from Terra-MODIS were obtained over the Greater Athens Area covering the period February 2000–December 2005. Based on both and FM values three main aerosol types have been discriminated corresponding to urban/industrial aerosols, clean maritime conditions, and coarse-mode, probably desert dust, particles. Five main sectors were identified for the classification of the air-mass trajectories, which were further used in the analysis of the ( and FM data for the three aerosol types). The HYSPLIT model was used to compute back trajectories at three altitudes to investigate the relation between -FM and wind sector depending on the altitude. The accumulation of local pollution is favored in spring and corresponds to air masses at lower altitudes originating from Eastern Europe and the Balkan. Clean maritime conditions are rare over Athens, limited in the winter season and associated with air masses from the Western or Northwestern sector. The coarse-mode particles origin seems to be more complicated proportionally to the season. Thus, in summer the Northern sector dominates, while in the other seasons, and especially in spring, the air masses belong to the Southern sector enriched with Saharan dust aerosols.

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