scholarly journals Анализ суперкаверн, формируемых при высокоскоростном движении в воде группой ударников

2022 ◽  
Vol 48 (1) ◽  
pp. 8
Author(s):  
А.Н. Ищенко ◽  
В.В. Буркин ◽  
А.С. Дьячковский ◽  
А.В. Чупашев ◽  
А.Ю. Саммель ◽  
...  
Keyword(s):  
High Speed ◽  
Mutual Influence ◽  
Qualitative Assessment ◽  
Characteristic Distance ◽  
Geometric Characteristics

The analysis of supercavities formed during the high-speed motion in water of two closely spaced supercavitating strikers is performed. By comparing of geometric characteristics of supercavities, the possibility of qualitative assessment of the degree of influence of closely spaced strikers is shown. By the example of two strikers, the characteristic distance between them was determined, at which the minimum mutual influence of the strikers on each other is observed.

An Experimental Study About the Effects of High Speed Rail’s Construction and Operation on the Ability of These Involving Enterprises

2012 ◽  
Author(s):  
Jing Yin ◽  
Xuemei Li ◽  
Zhuxue Guo
Keyword(s):  
Experimental Study ◽  
Evaluation System ◽  
High Speed ◽  
Mutual Influence ◽  
Comprehensive Evaluation ◽  
Time Dimension ◽  
High Speed Rail ◽  
Industry Chain ◽  
Complex Processes ◽  
Previous Part

Since High-Speed Rail (HSR) began planned and constructed, many involving enterprises obtain interests from the process. But with increasing number of High-Speed railways being planned, constructed, and then operated, it will inevitably bring more improvement on the ability of these involving enterprises. So, no matter policy planers and the entrepreneurs or investors, understand the inner mechanism of the mutual influence between the development of High-Speed Rail and the improvement of involving enterprises is a key point to keep harmonious and efficient development of infrastructure construction simultaneously with the enterprises. In this paper, it is presented an example of an experimental study investigating the effects of high speed rail’s construction and operation on these involving enterprises in each link of this high speed rail industry chain. As we know, social division of labor improves the efficiency of society, and with more detailed-oriented division, more enterprises and experts are engaged in one or several domains. Thus the construction and operation of high speed way are complex processes completed by numerous enterprises, each one or some of which only need to deal with one part. By sorting the industry chain of high speed rail, 50 listed enterprises are selected with their operated data from 2006 to 2010. The comprehensive evaluation system of enterprises ability is modeled by factor analysis method to obtain the key factors, which affect the development of enterprises. The results show the ability of these enterprises are influenced by their scale, profitability, debt, operation ability and progressive ability, and the enterprises in different link own their special abilities compared with those of other links. And next, from the time dimension, the abilities of enterprises have been changed from 2006 to 2010, especially one or several abilities that summarized in the previous part. So via variance analysis, the change laws of ability are explored in the process of construction and operation of high speed rail, which, on one hand, is confirmed the promotion of high speed rails to these abilities of enterprises, on the other hand, shows the inner mechanism and rules in the process.

scholarly journals Hemodynamic conditions that favor bleb formation in cerebral aneurysms

2020 ◽  
pp. neurintsurg-2020-016369 ◽  
Author(s):  
Seyedeh Fatemeh Salimi Ashkezari ◽  
Fernando Mut ◽  
Bong Jae Chung ◽  
Anne M Robertson ◽  
Juan R Cebral
Keyword(s):  
Intracranial Aneurysms ◽  
High Speed ◽  
Cerebral Aneurysms ◽  
Vascular Reconstruction ◽  
Flow Patterns ◽  
Patient Specific ◽  
Unstable Flow ◽  
Geometric Characteristics ◽  
Irregular Shapes ◽  
Bleb Formation

BackgroundAlthough it is generally believed that blebs represent weaker spots in the walls of intracranial aneurysms (IAs), it is largely unknown which aneurysm characteristics favor their development.ObjectiveTo investigate possible associations between aneurysm hemodynamic and geometric characteristics and the development of blebs in intracranial aneurysms.MethodsA total of 270 IAs in 199 patients selected for surgical clipping were studied. Blebs were visually identified and interactively marked on patient-specific vascular models constructed from presurgical images. Blebs were then deleted from the vascular reconstruction to approximate the aneurysm before bleb formation. Computational fluid dynamics studies were performed in these models and in cases without blebs. Hemodynamic and geometric characteristics of aneurysms with and without blebs were compared.ResultsA total of 173 aneurysms had no blebs, while 97 aneurysms had a total of 122 blebs. Aneurysms favoring bleb formation had stronger (p<0.0001) and more concentrated inflow jets (p<0.0001), higher flow velocity (p=0.0061), more complex (p<0.0001) and unstable (p=0.0157) flow patterns, larger maximum wall shear stress (WSS; p<0.0001), more concentrated (p=0.0005) and oscillatory (p=0.0004) WSS distribution, and a more heterogeneous WSS field (p<0.0001), than aneurysms without blebs. They were also larger (p<0.0001), more elongated (p<0.0001), had wider necks (p=0.0002), and more distorted and irregular shapes (p<0.0001).ConclusionsStrong and concentrated inflow jets, high-speed, complex, and unstable flow patterns, and concentrated, oscillatory, and heterogeneous WSS patterns favor the formation of blebs in IAs. Blebs are more likely to form in large, elongated, and irregularly shaped aneurysms. These adverse characteristics could be considered signs of aneurysm instability when evaluating aneurysms for conservative observation or treatment.

High-Speed Sealift Technology

1998 ◽  
Vol 35 (03) ◽  
pp. 135-150
Author(s):  
Colen Kennell ◽  
David R. Lavis ◽  
Michael T. Templeman
Keyword(s):  
High Speed ◽  
Empirical Method ◽  
Qualitative Assessment ◽  
Sea Transport ◽  
Relative Risks ◽  
Speed Range ◽  
Near Term ◽  
Design Characteristics ◽  
Impact Of Technology ◽  
The Impact

This paper describes a process that is currently being used within DoD and industry to examine the possibilities offered by technology to enhance the transport performance of high-speed commercial and military sealift. Technology projections are presented for both the near-term and the far-term. The impact of technology projections on transport performance properties is assessed both quantitatively and qualitatively. These assessments provide significant insight into the overall transport performance potential of hullforms and other technologies of interest, considerably in advance of detailed design studies. The quantitative assessment uses a derivation of the empirical method published by Kennell[1]4, which provides simple parametric relationships between mission requirements, expressed in terms of speed, range and payload, and design characteristics, expressed in terms of displacement, installed power and fuel weight, to compare the various hullforms and other technologies of interest. The qualitative assessment applies an established decision-making method to ascertain the relative capabilities and relative risks of hullforms and other technologies of interest for significant aspects of sea transport, other than speed, range and payload. While the methods used are generic, the data selected and results presented are aimed at ships capable of rapidly transporting heavy cargo over long distances.

DEVELOPMENT OF A METHOD OF HYDROEROSIVE SATURATION OF LIQUIDS WITH MICROPARTICLES OF TARGET MATERIALS USING ULTRAJET

2020 ◽  
pp. 3-11
Author(s):  
A. L. Galinovisky ◽  
S. A. Erokhin ◽  
Tszia Chzheniuan
Keyword(s):  
Carbon Fiber ◽  
High Speed ◽  
Inhibitory Effect ◽  
Qualitative Assessment ◽  
Fiber Structure ◽  
Initial State ◽  
X Ray ◽  
Fiber Reinforced Plastic ◽  
Carbon Plastics ◽  
Reinforced Plastic

The article is deal with the questions of assessing the applicability of the method of ultra-jet diagnostics of carbon plastics. In the work, phenomenological ideas about the process of destruction of carbon plastics under the action of a high-speed-jet of liquid are considered. The experimental part of the work is related to the implementation of the diagnostic effect of the ultra-jet on the surface of the carbon fiber reinforced plastic, the assessment of the geometric parameters of the hydraulic caverns and the qualitative assessment of the state of the fibers and the adhesion in the binder-fiber structure. In this experiment, carbon fiber samples were used both in the initial state and after the inhibitory effect of x-ray radiation. Such a technique made it possible to carry out a comparative analysis of the samples and evaluate the information content of the ultra-jet diagnostics method as applied to the materials under consideration.

scholarly journals Analysis of Subjective Qualitative Judgement of Passenger Vehicle High Speed Drivability due to Aerodynamics

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2839 ◽  
Author(s):  
Arun Kumar ◽  
Simone Sebben ◽  
Erik Sällström ◽  
Bengt J.H. Jacobson ◽  
Alexander Broniewicz
Keyword(s):  
High Speed ◽  
Lateral Acceleration ◽  
Qualitative Assessment ◽  
Measurement Unit ◽  
External Disturbances ◽  
Straight Line ◽  
Subjective Judgement ◽  
Transient Events ◽  
Vehicle Test ◽  
Steering Torque

The flow created by the shape of a vehicle and by environmental conditions, such as cross-winds, will influence the dynamics of a vehicle. The objective of this paper is to correlate the driver’s subjective judgement of drivability with quantities which are measurable during a vehicle test. For this purpose, a sedan vehicle, fitted with different aerodynamic external devices that create disturbances in the flow field, were assessed on a test track. These configurations intend to result in substandard straight line drivability. The aerodynamic devices investigated are an inverted wing, an inverted wing with an asymmetric flat plate and an asymmetric air curtain attached under the bumper. The devices generate more lift and asymmetric forces resulting in increased vehicle sensitivity to external disturbances. Pairs of configurations with and without bumper side-kicks are also tested. The side-kicks create a defined flow separation which helps to stabilize the flow and increase drivability. Plots of mean and standard deviation and ride diagram of lateral acceleration, yaw velocity, steering angle and steering torque are used to understand vehicle behaviour for the different configurations. Ride diagrams are used to visualize vehicle excitations with transient events separated from the stationary signal. The range of the measured quantities for understanding the drivability is not predicted in advance and it turns out that the error margins of the measurements are smaller than the measurement uncertainty of the Inertia Measurement Unit. Although the outcome lacks the ability to objectively quantify subjective judgements, it provides a useful qualitative assessment of the problem as the trends agree well with the subjective judgement of the driver.

The Friction and Wear Properties of VC Coating by TD Process

2010 ◽  
Vol 33 ◽  
pp. 61-65 ◽  
Author(s):  
Chao Zheng Zhou ◽  
De Jun Kong ◽  
Yu Feng Yan
Keyword(s):  
Crack Growth ◽  
Wear Mechanism ◽  
High Speed ◽  
Friction And Wear ◽  
Cold Working ◽  
Mutual Influence ◽  
Wear Properties ◽  
Fatigue Wear ◽  
Friction And Wear Properties ◽  
Surface Morphologies

VC coating was prepared on the surface of Cr12MoV cold working die steel by TD process, and its friction and wear properties were researched with HSR-2M type high-speed reciprocating friction and wear tester, the effects of load on friction and wear properties were discussed, and the wear surface morphologies were observed with SEM. The experimental results shown that fatigue wear and adhesive wear are mainly wear mechanism of VC coating, and the different parts have an influence on wear mechanism; When cracks occurs, the crack growth is the combined result of mutual influence of elastic-plastic crack growth and fatigue crack growth; There is no relationship between friction coefficient and load, and the wear rate increases with the load.

Numerical Simulation Research of Air-Assisted Atomizer Internal Gas Flow Field Based on Fluent

2014 ◽  
Vol 599-601 ◽  
pp. 377-380
Author(s):  
Qiao Li ◽  
Ya Yu Huang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Total Pressure ◽  
High Speed ◽  
Gas Flow ◽  
Static Pressure ◽  
Mutual Influence ◽  
Simulation Research ◽  
Simulation Calculation ◽  
Gas Flow Field

The numerical simulation calculation of air-assisted atomizer internal gas flow field is done, the distribution and changes of the nozzle inside flow field total pressure, velocity, and dynamic and static pressure are analyzed. The analysis shows that the total pressure loss is less; due to the effect of gas viscous, the high-speed air flow is formed vortex flow near the outlet nozzle and the mutual influence between the dynamic and static pressure. A new way is supported for optimizing the nozzle structure according to these studies.

Magnetic Levitation Transportation Technologies as an Innovative Infrastructure Framework for the Formation of Global Eurasia

2021 ◽  
Vol 26 (11) ◽  
pp. 1180-1189
Author(s):  
V. A. Tsvetkov ◽  
K. Kh. Zoidov ◽  
A. A. Medkov
Keyword(s):  
High Speed ◽  
Economies Of Scale ◽  
System Analysis ◽  
Magnetic Levitation ◽  
Mutual Influence ◽  
Spare Parts ◽  
Transport Systems ◽  
Competitive Advantages ◽  
The North ◽  
Transportation Technologies

The presented study determines the prospects for implementing and spreading transportation technologies based on the principles of magnetic levitation as an innovative infrastructure framework for the formation of Global Eurasia.Aim. The study aims to determine and analyze the mutual influence of integration processes in the formation of Global Eurasia and the spread of transportation technologies based on the principles of magnetic levitation within this space, particularly along the North-South line, as the foundation for socio-economic, industrial, and technological priority development of the region’s countries.Tasks. The authors reveal the limited applicability of the traditional principle of wheel-rail movement in modern reality; indicate the undesirability and impossibility of blindly copying magnetic levitationbased movement projects implemented abroad; consider vacuum-levitation transport systems (VLTS) as innovative infrastructure projects that are too radical, excessive in quality, expensive to implement, and limited in the scope of application; determine the undesirability factors of priority development of passenger Maglev transport over cargo transport; systematize the competitive advantages and implementation problems of the North-South high-speed cargo transit highway project and the technological competitive advantages of the open Maglev system.Methods. This study uses the methods of system analysis, theory of techno-economic paradigms, manufacturing-technological balance of the economy, evolutionary-institutional theory, and worldsystem analysis.Results. The authors verify the hypothesis that the mutual influence of integration processes in the formation of Global Eurasia and the spread of transportation technologies based on the principles of magnetic levitation within this space, particularly along the North-South line, serve as a foundation for socio-economic, industrial, and technological priority development of the region’s countries, allowing them to become global leaders in the future.Conclusions. The study proves that adaptation and localization of production of advanced traditional high-speed highway systems based on the wheel-rail principle in Russia will not change the catchingup nature of development of the country’s transit transport system. It also shows that transportation by Maglev trains combines the advantages of both mass modes of transport and high-speed movement. This type of transportation is therefore attractive to customers who use a combination of the maritime fleet or traditional railways and air transport. The authors emphasize the need for mass production and distribution of Maglev technology and its application over long distances, which will help to achieve economies of scale, develop manufacturing and technological competencies, ensure operational safety, and provide a sufficient number of spare parts and components.

SOIL COVER STRUCTURE AND CROPS CULTIVATION TECHNOLOGIES

1970 ◽  
pp. 53-57
Author(s):  
V. P. Belobrov ◽  
S. А. Yudin ◽  
N. R. Ermolaev ◽  
А. L. Ivanov ◽  
V. K. Dridiger ◽  
...  
Keyword(s):  
New Technologies ◽  
Soil Cover ◽  
Mutual Influence ◽  
Farming Systems ◽  
Farming System ◽  
Climatic Conditions ◽  
Qualitative Assessment ◽  
Soil Cover Structure ◽  
The Impact ◽  
Direct Sowing

The variability of morphometric indicators of typical chernozems is considered based on long-term field experiment in a grain 4-field crop rotation (winter wheat, corn, barley, peas) to assess the impact of plowing as a traditional farming system that uses soil treatment and no-till, in which plowing is not used. On the example of four experimental fields (each with an area of 2.4 hectares), the variation of indicators associated with the features of the soil cover structure and the applied farming systems was revealed. The tillage leads to an increase in the thickness of the soil profile leached from carbonates, and direct sowing leads to its decrease. The highest variability degree is found in the boiling depth of soil. It is shown that the tillage leads to the homogenization of the soils surface layer and the transformation of the soil cover structure, as a kind of ”insurance system " against weather risks reducing its effectiveness. The direct sowing usage leads to the restoration of degraded properties and natural of soils heterogeneity in the soil cover structures, which can be considered as a process aimed at ecological improvement of both specifiс soil sites and the soil cover structures. The mutual influence of the soil cover structure and agricultural systems can be traced in time and space. The soil structure and the cultivated crops yield related to the sustainability of agrosystems to adverse climatic conditions and other risk. For these it is necessary monitoring soil as the basis for the qualitative assessment of soil and selection of the most optimal directions of agriculture development, a new technologies development in the production of agricultural products.

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