scholarly journals Development of Executive Equipment Design for Implementing the Process of Generating of Drops of Microand Nanoscale Range

2021 ◽  
Vol 12 (1) ◽  
pp. 38-45
Author(s):  
M. A. Kuznetsov ◽  
D. P. Ilyaschenko ◽  
A. V. Kryukov ◽  
S. A. Solodsky ◽  
E. V. Lavrova ◽  
...  
Keyword(s):  
Surface Waves ◽  
Plasma Flow ◽  
Plasma Torch ◽  
Design Feature ◽  
Metal Droplet ◽  
Droplet Surface ◽  
Geometric Parameters ◽  
Design Features ◽  
Plasma Flows ◽  
Nanoscale Range

Modeling of velocities and temperatures processes distribution in the plasma-forming channel determining the design features and optimal parameters of the plasma torch nozzle is one of promising directions in development of plasma technologies. The aim of this work was to simulate the processes of velocities and temperature distribution in the plasma-forming channel and to determine the design features and optimal geometric parameters of the plasmatron nozzle  which  ensures  the  formation  of  necessary  direction  of  plasma  flows for generation of surface waves on the surface of a liquid metal droplet under the influence of the investigated instabilities.One of the main tasks is to consider the process of plasma jet formation and the flow of electric arc plasma. For obtaining small-sized particles one of the main parameters is the plasma flow  velocity.  It  is necessary that the plasma outflow velocity be close to supersonic. An increase of  the  supersonic  speed  is possible due to design of the plasmatron nozzle especially the design feature and dimensions of the gas channel in which the plasma is formed. Also the modeling took into account dimensions of the plasma torch nozzle, i. e. the device should provide a supersonic plasma flow with the smallest possible geometric dimensions.As a result models of velocities and temperatures distribution in the plasma-forming channel at the minimum and maximum diameters of the channel were obtained. The design features and optimal geometric parameters of the plasmatron have been determined: the inlet diameter is 3 mm, the outlet diameter is 2 mm.The design of the executive equipment has been developed and designed which implements the investigated process of generating droplets of the micro- and nanoscale range. A plasmatron nozzle was manufactured which forms the necessary directions of plasma flows for the formation of surface waves on the metal droplet surface under the influence of instabilities. An algorithm has been developed for controlling of executive equipment that implements the process of generating drops of micro- and nanoscale range.

scholarly journals Plasma transport along discrete auroral arcs and its contribution to the ionospheric plasma convection

2008 ◽  
Vol 26 (11) ◽  
pp. 3279-3293 ◽  
Author(s):  
A. Kullen ◽  
S. Buchert ◽  
T. Karlsson ◽  
T. Johansson ◽  
S. Lileo ◽  
...  
Keyword(s):  
Plasma Flow ◽  
Strong Dependence ◽  
Background Plasma ◽  
Plasma Transport ◽  
Plasma Convection ◽  
Plasma Flows ◽  
Maximum Phase ◽  
Field Peak ◽  
Auroral Arcs

Abstract. The role of intense high-altitude electric field (E-field) peaks for large-scale plasma convection is investigated with the help of Cluster E-field, B-field and density data. The study covers 32 E-field events between 4 and 7 RE geocentric distance, with E-field magnitudes in the range 500–1000 mV/m when mapped to ionospheric altitude. We focus on E-field structures above the ionosphere that are typically coupled to discrete auroral arcs and their return current region. Connected to such E-field peaks are rapid plasma flows directed along the discrete arcs in opposite directions on each side of the arc. Nearly all the E-field events occur during active times. A strong dependence on different substorm phases is found: a majority of intense E-field events appearing during substorm expansion or maximum phase are located on the nightside oval, while most recovery events occur on the dusk-to-dayside part of the oval. For most expansion and maximum phase cases, the average background plasma flow is in the sunward direction. For a majority of recovery events, the flow is in the anti-sunward direction. The net plasma flux connected to a strong E-field peak is in two thirds of the cases in the same direction as the background plasma flow. However, in only one third of the cases the strong flux caused by an E-field peak makes an important contribution to the plasma transport within the boundary plasma sheet. For a majority of events, the area covered by rapid plasma flows above discrete arcs is too small to have an effect on the global convection. This questions the role of discrete auroral arcs as major driver of plasma convection.

scholarly journals An approach to automatic boundary segmentation of solid models using virtual topology: toward reconstruction of design features

2020 ◽  
Vol 7 (3) ◽  
pp. 367-385
Author(s):  
Yingzhong Zhang ◽  
Yufei Fu ◽  
Jia Jia ◽  
Xiaofang Luo
Keyword(s):  
Design Feature ◽  
Boundary Representation ◽  
Virtual Topology ◽  
Design Features ◽  
Complex Part ◽  
Novel Approach ◽  
Solid Models ◽  
Medium Level ◽  
Feature Based ◽  
Low Dimensional

Abstract Boundary segmentation of solid models is the geometric foundation to reconstruct design features. In this paper, based on the shape evolution analysis for the feature-based modeling process, a novel approach to the automatic boundary segmentation of solid models for reconstructing design features is proposed. The presented approach simulates the designer’s decomposing thinking on how to decompose an existing boundary representation model into a set of design features. First, the modeling traces of design features are formally represented as a set of feature vertex adjacent graphs that use low-dimensional vertex entities and their connection relations. Then, a set of Boolean segmentation loops is searched and extracted from the constructed feature vertex adjacent graphs, which segment the boundary of a solid model into a set of regions with different design feature semantics. In the search process, virtual topology operations are employed to simulate the topological changes resulting from Boolean operations in feature modeling processes. In addition, to realize effective search, search strategies and search algorithms are presented. The segmentation experiments and case study show that the presented approach is feasible and effective for the boundary segmentation of medium-level complex part models. The presented approach lays the foundation for the later reconstruction of design features.

Radiation Pressure Dominated Plasma Flow

1979 ◽  
Vol 34 (9) ◽  
pp. 1059-1062 ◽  
Author(s):  
P. Mulser ◽  
G. Spindler
Keyword(s):  
Supersonic Flow ◽  
Radiation Pressure ◽  
Plasma Flow ◽  
Thermal Transport ◽  
Laser Pulses ◽  
Numerical Calculations ◽  
Plasma Flows ◽  
Light Pressure ◽  
Spherical Plasma

Abstract The influence of light pressure on plane and spherical plasma flows is treated. Numerical calculations show that smooth laser pulses lead to formation of an overdense plateau if thermal transport is non-negligible there, and that an originally supersonic flow becomes subsonic in this region. The results are consistent with analytical considerations. Density humps, as reported in the literature, are found in conjunction with spiking pulses or prepulses only.

Kinetic theory of surface waves in a semibounded plasma flow

2000 ◽  
Vol 45 (4) ◽  
pp. 396-399 ◽  
Author(s):  
A. F. Aleksandrov ◽  
A. A. Rukhadze
Keyword(s):  
Kinetic Theory ◽  
Surface Waves ◽  
Plasma Flow ◽  
Semibounded Plasma

scholarly journals VISUALIZATION OF THE gas-dynamic STRUCTURE OF PLASMA FLOWS OF A PNK-50 plasma torchusing THE SHADOW METHOD

2018 ◽  
Vol 14 (4) ◽  
pp. 61-68 ◽  
Author(s):  
I P Gulyaev ◽  
V I Kuzmin ◽  
M P Golubev ◽  
P A Tyryshkin ◽  
A V Dolmatov
Keyword(s):  
Plasma Torch ◽  
Dynamic Structure ◽  
Reynolds Numbers ◽  
Air Plasma ◽  
Plasma Flows ◽  
Output Section ◽  
Modes Of Operation ◽  
Turbulent Transition ◽  
Gas Dynamic ◽  
Additional Mode

The paper presents the study of the gas-dynamic structure of air plasma flows produced by the PNK-50 spray torch using the shadow (schlieren) method. The operation of the plasma torch was studied in three different configurations, differing, among other things, by the diameter of the output section of the channel: 6, 8, 10 mm. The subsonic and supersonic modes of operation of the plasma torch were investigated in the range of plasma-forming air flow 1.4-10.5 g / s and arc current range 140-230 A.In all typical modes of operation of the plasma torch, the flow has a developed turbulent structure with a full angle of jet opening between 23 and 27 degrees. An additional mode of operation of the plasma torch with an output nozzle diameter of 14 mm allowed the realization of a laminar flow regime. It is established that the laminar-turbulent transition is observed in the range of Reynolds numbers 400 - 900. The pattern of supersonic flow impinging a flat barrier - a substrate for placedat a distance of 85 mm from the plasma torch, is visualized.

Comment on ‘Boundary conditions for surface waves propagating along the interface of plasma flow and free space’

1999 ◽  
Vol 61 (1) ◽  
pp. 169-171 ◽  
Author(s):  
MAGDI SHOUCRI
Keyword(s):  
Dispersion Relation ◽  
Boundary Conditions ◽  
Surface Waves ◽  
Plasma Flow ◽  
Free Space ◽  
Plasma Phys ◽  
Plane Interface

The dispersion relation and boundary conditions for surface waves propagating on the plane interface between a vacuum and a drifting plasma have recently been derived by Lee and Cho [J. Plasma Phys.58, 409 (1997)]. It is the purpose of the present comment to show that the boundary conditions and dispersion relation are incorrect.

A New Approach to Generic Design Feature Recognition by Detecting the Hint of Topology Variation

2012 ◽  
Author(s):  
Sha Wan ◽  
Yunbao Huang ◽  
Qifu Wang ◽  
Liping Chen ◽  
Yuhang Sun
Keyword(s):  
Feature Recognition ◽  
Design Feature ◽  
Design Features ◽  
Hybrid Features ◽  
New Approach ◽  
Complex Part ◽  
Current Design ◽  
Cad Models ◽  
Core Idea ◽  
Generic Design

Current design feature recognition mainly depends on the connective attributes of edges or faces in the CAD models, such as convexity, concavity, and tangency. However, it is difficult to uniquely define the mixed connective attributes of the generic features in some cases. A novel generic design feature recognition approach by detecting the hint of topology variation is presented in this study. The core idea includes: 1) the resulting CAD model of a complex part is regarded as formed from an initial basic shape such as roughcast and has been operated by introducing generic design features, which subsequently may cause topology variation; 2) Such topology variations, e.g. vertex elimination, edge partition and face alteration, are utilized to obtain generalized properties of the generic design features, dispensing with the connective attributes. Finally, 1) we demonstrate in the experiments that the approach successfully recognizes the main types of generic design features, both isolate and hybrid features. 2) Furthermore, we exhibit the application of the approach in some engineering examples.

scholarly journals Environmental design feature

Mechanik ◽  
2020 ◽  
Vol 93 (1) ◽  
pp. 42-47
Author(s):  
Józef Flizikowski
Keyword(s):  
Turbine Blades ◽  
Environmental Design ◽  
Design Feature ◽  
Structure Design ◽  
Machine Construction ◽  
Design Features ◽  
Environmental Characteristic ◽  
General Outline ◽  
Design Elements ◽  
Rational Development

The purpose of the study is to identify the need to address the environmental, usability and harmfulness of the structure (design), the rational development of the essence of the fourth design feature of machine components, equipment and other engineering and technical facilities as well as the environment. Known to the designers of machine construction and technology, three design features are commonly used: geometric, material and dynamic, oriented on the form, dimension and tolerance of the outer form, internal structure and the assembly capabilities of the design elements. The development of technology indicates the possibility of expending the concept of three design features, along with an environmental characteristic, as the root causes, functional and secondary existence of machinery, equipment, installation, also the environment. The aim of the study was achieved, indicating environmental useful values of the structure, in the proposal for a general outline of the essence of the fourth design feature of machine components, equipment and other engineering and technical facilities, on the example of turbine blades of windmills.

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