Precipitation of aerosols in the boundary layers of flat surfaces of power plants

2020 ◽  
pp. 42-47
Author(s):  
SERGIY RYZHKOV
Keyword(s):  
Boundary Layers ◽  
Power Plants ◽  
Jet Stream ◽  
Flat Surfaces

Fractonal efciency of aerosol collecton in the boundary layers at diferent inital speeds of disperse multphase fow along a fat surface with the jet stream is determined.

scholarly journals Three-dimensional surface printing method for interconnecting electrodes on opposite sides of substrates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Md. Khalilur Rahman ◽  
Seong-jun Kim ◽  
Thanh Huy Phung ◽  
Jin-Sol Lee ◽  
Jaeryul Yu ◽  
...  
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Electrical Signal ◽  
Jet Stream ◽  
Flat Surfaces ◽  
Direct Printing ◽  
Fine Pattern ◽  
Sharp Edges ◽  
Glass Surfaces ◽  
Printing Method

Abstract As the application of the direct printing method becomes diversified, printing on substrates with non-flat surfaces is increasingly required. However, printing on three-dimensional surfaces suffers from a number of difficulties, which include ink flow due to gravity, and the connection of print lines over sharp edges. This study presents an effective way to print a fine pattern (~ 30 μm) on three different faces with sharp edge boundaries. The method uses a deflectable and stretchable jet stream of conductive ink, which is produced by near-field electrospinning (NFES) technique. Due to added polymer in the ink, the jet stream from the nozzle is less likely to be disconnected, even when it is deposited over sharp edges of objects. As a practical industrial application, we demonstrate that the method can be effectively used for recent display applications, which require the connection of electrical signal and power on both sides of the glass. When the total length of printed lines along the ‘Π’ shaped glass surfaces was 1.2 mm, we could achieve the average resistance of 0.84 Ω.

Mathematical Modeling of Dusty-Gas Boundary Layers

1997 ◽  
Vol 50 (6) ◽  
pp. 357-370 ◽  
Author(s):  
A. N. Osiptsov
Keyword(s):  
Mathematical Modeling ◽  
Boundary Layers ◽  
Expansion Method ◽  
Heat Fluxes ◽  
Matched Asymptotic Expansion ◽  
Dusty Gas ◽  
Two Phase ◽  
Flat Surfaces ◽  
Laminar Boundary Layers ◽  
Further Development

This article reviews the state of the art in the mathematical modeling of dusty-gas laminar boundary layers in the framework of the two-fluid approach. Main attention is paid to the strict formulation of the two-phase boundary layer approximation, using the matched asymptotic expansion method. The low and high-velocity boundary layers both on curve and flat surfaces are considered. The particle accumulation in the boundary layers and the effects of particles on the friction and heat fluxes are examined. Important advances in the field of study are summarized and the areas deserving further development are discussed. This review article has 107 references.

Measurement of Three-Dimensional Boundary Layers

1969 ◽  
Vol 73 (705) ◽  
pp. 796-798 ◽  
Author(s):  
B. K. Rogers ◽  
M. R. Head
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Three Dimensional ◽  
Present Form ◽  
Mean Flow ◽  
Flat Surfaces ◽  
Dimensional Boundary ◽  
Flow Directions

The instrument described here is designed to measure mean flow directions and velocities in the three-dimensional boundary layer. Its particular advantage is the small amount of interference it introduces, while allowing measurements to be made close to the surface and providing an acceptably large traverse distance normal to it. In its present form it is restricted, however, to flat surfaces where space beneath the surface is not at a premium.

Laminar and Turbulent Boundary Layers on Moving, Nonisothermal Continuous Flat Surfaces

1982 ◽  
Vol 104 (4) ◽  
pp. 707-714 ◽  
Author(s):  
A. Moutsoglou ◽  
A. K. Bhattacharya
Keyword(s):  
Heat Transfer ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Moving Plate ◽  
Flat Surfaces ◽  
Eddy Diffusivities ◽  
Stress Surface ◽  
Continuous Plate ◽  
Surface Temperature Variation ◽  
Good Agreement

The heat-transfer characteristics of buoyancy-affected laminar and turbulent boundary layers on nonisothermal continuous flat surfaces that move steadily through a quiescent ambient fluid are studied analytically. Both cooling and heating of the continuous plate which is moving upward or downward in a horizontal, vertical, or inclined direction are considered. A mixing length model for the eddy diffusivities of momentum and heat based on an extension of the Van Driest model is employed in the turbulent boundary layers. Numerical results, such as wall shear stress, surface heat-transfer rate, and surface temperature variation, are presented for various Reynolds and Grashof numbers for fluids with a Prandtl number of 0.7, for both laminar and turbulent boundary layers. A good agreement is found between the analytical and experimental results for friction factor in turbulent boundary layer over an isothermal, continuous moving plate.

scholarly journals Improving the acoustic efficiency of laminated dissipative noise silencers for boiler gas-air paths

2019 ◽  
Vol 140 ◽  
pp. 02005
Author(s):  
Evgeniy Zhuravlev ◽  
Dmitry Chugunkov ◽  
Galina Seyfelmlyukova
Keyword(s):  
Power Plants ◽  
Negative Impact ◽  
Thermal Power ◽  
Aerodynamic Characteristics ◽  
Sound Attenuation ◽  
Thermal Power Plants ◽  
Flat Surfaces ◽  
Reduction Efficiency ◽  
Side Walls ◽  
Plate Type

The operation of thermal power facilities is associated with the negative impact on the environment and humans of such factors as air, water, soil pollution, electromagnetic radiation, and noise. This article is devoted to improving the noise reduction efficiency of gas and air paths of boilers of thermal power plants. In world practice, to reduce noise in gas-air ducts, dissipative noise silencers are used. The authors propose a new design of sound attenuation elements for dissipative plate-type silencers. The article defines the acoustic and aerodynamic characteristics of noise silencers with new sound attenuation elements. We compare the characteristics of silencers made of new silencing elements and the characteristics of silencers consisting of plates of common design with flat surfaces of the side walls, and demonstrate an increase in acoustic efficiency and a decrease in pressure loss when using the proposed new silencing elements in noise silencers. Recommendations on the use of dissipative plate-type silencers with developed sound attenuation elements for gas-air paths of boilers are given.

HREM observation of dislocations near room temperature fractures in silicon

1988 ◽  
Vol 46 ◽  
pp. 892-893
Author(s):  
M. H. Rhee ◽  
W. A. Coghlan
Keyword(s):  
Cross Section ◽  
Room Temperature ◽  
Single Crystal Silicon ◽  
Dislocation Nucleation ◽  
Back Side ◽  
Ion Milling ◽  
Crystal Silicon ◽  
Flat Surfaces ◽  
Induced Fractures ◽  
Vicker’S Microhardness

Silicon is believed to be an almost perfectly brittle material with cleavage occurring on {111} planes. In such a material at room temperature cleavage is expected to occur prior to any dislocation nucleation. This behavior suggests that cleavage fracture may be used to produce usable flat surfaces. Attempts to show this have failed. Such fractures produced in semiconductor silicon tend to occur on planes of variable orientation resulting in surfaces with a poor surface finish. In order to learn more about the mechanisms involved in fracture of silicon we began a HREM study of hardness indent induced fractures in thin samples of oxidized silicon.Samples of single crystal silicon were oxidized in air for 100 hours at 1000°C. Two pieces of this material were glued together and 500 μm thick cross-section samples were cut from the combined piece. The cross-section samples were indented using a Vicker's microhardness tester to produce cracks. The cracks in the samples were preserved by thinning from the back side using a combination of mechanical grinding and ion milling.

Sign in / Sign up

Export Citation Format

Share Document