scholarly journals Method for modeling a bore chamfer in a hull within the scope of submarine shipbuilding for welding-in of outfitting Part 2 Mathematical description of hole groove in spherical and conical sections of hulls

2020 ◽  
pp. 41-48
Author(s):  
С.А. Русановский ◽  
М.П. Худяков ◽  
Н.И. Черенков
Keyword(s):  
Mathematical Description ◽  
Geometric Modeling ◽  
Stationary Process ◽  
Intermediate Stage ◽  
Matrix Form ◽  
Process Systems ◽  
Groove Guide

Статья является логическим продолжением первой части (№1, 2020), в которой была предложена методика геометрического моделирования кромок отверстий на цилиндрических участках обечаек. В этой части рассмотрено математическое описание кромок отверстий в сферических и конических участках корпусов. Показано, что поверхность кромки отверстий может быть описана как дважды косой цилиндроид или косой коноид в зависимости от требований к разделке.Полученные выражения для описания кромок отверстий могут быть представлены в аналитическом и матричном виде (в однородных координатах). Также полученные выражения могут быть использованы в качестве промежуточного этапа в предложенной методике проектирования технологических комплексов. Отмечено, что получаемую криволинейную направляющую разделки кромки можно использовать в качестве связи между обрабатываемым изделием и обрабатывающим инструментом для механической обработки кромок отверстий с помощью нестационарных технологических комплексов. The article is a logical continuation of the first part (No. 1, 2020), in which a method for geometric modeling of hole grooves on cylindrical sections of shells has been proposed. Mathematical description of hole grooves in spherical and conical sections of hulls has been studied in the current part. It is shown that surface of a hole groove can be described as double oblique cylindroid or oblique conoid depending on groove preparation. Received expressions for describing the hole grooves can be shown in analytical and matrix form (in uniform coordinates). Also received expressions can be used as an intermediate stage in the proposed methodology for the design of process systems. It is noted that the resulting curvilinear groove guide can be used as a connection between the workpiece and the machining tool for machining the hole grooves using non-stationary process systems.

Solar Filaments as Tracers of Subsurface Processes

2000 ◽  
Vol 179 ◽  
pp. 177-183
Author(s):  
D. M. Rust
Keyword(s):  
Magnetic Fields ◽  
Magnetic Flux ◽  
Coronal Mass Ejections ◽  
Interplanetary Space ◽  
Intermediate Stage ◽  
Coronal Plasma ◽  
Magnetic Helicity ◽  
The Sun ◽  
New Paradigm ◽  
Solar Filaments

AbstractSolar filaments are discussed in terms of two contrasting paradigms. The standard paradigm is that filaments are formed by condensation of coronal plasma into magnetic fields that are twisted or dimpled as a consequence of motions of the fields’ sources in the photosphere. According to a new paradigm, filaments form in rising, twisted flux ropes and are a necessary intermediate stage in the transfer to interplanetary space of dynamo-generated magnetic flux. It is argued that the accumulation of magnetic helicity in filaments and their coronal surroundings leads to filament eruptions and coronal mass ejections. These ejections relieve the Sun of the flux generated by the dynamo and make way for the flux of the next cycle.

Study on the Modes of Operation of a Multi-Machine Installations with Mechanical Reduction

2019 ◽  
pp. 12-22
Author(s):  
A. M. Oleynikov ◽  
L. N. Kanov
Keyword(s):  
Mathematical Description ◽  
Reactive Power ◽  
Maximum Efficiency ◽  
Wind Flow ◽  
System Of Equations ◽  
Mechanical Equilibrium ◽  
Synchronous Generators ◽  
Electromagnetic Excitation ◽  
Number Of Generators ◽  
Wide Range

The paper gives the description of the original wind electrical installation with mechanical reduction in which the output of vertical axis wind turbine with rather low rotation speed over multiplicator is distributed to a certain number of generators. The number of acting generators is determined by the output of actual operating wind stream at each moment. According to this constructive scheme, it is possible to provide effective and with maximum efficiency installation work in a wide range of wind speeds and under any schedule issued to the consumer of electricity. As there are no any experience in using such complexes, mathematical description of its main elements is given, namely windwheels, generators with electromagnetic excitation of magnetic electrical type, then their interaction with windwheel, and also the results of mathematical modeling of work system regimes under using the offered system of equations. The basis for the mathematical description of the main elements of the installation – synchronous generators – are the system of equations of electrical and mechanical equilibrium in relative units in rotating coordinates without considering saturation of the magnetic circuit. The equation of mechanical equilibrium systems includes torque and brake windwheel electromagnetic moments of generators with taking into account the reduction coefficients and friction. In addition, we specify the alternator rotor dynamics resulting from continuous torque of windwheel fluctuations under the influence of unsteady wind flow and wind speed serving as the original variable is modeled by a set of sinusoids. Model simplification is achieved by equivalization of similar generators and by disregarding these transitions with a small time constant. Calculation the installation with synchronous generators of two types of small and medium capacity taking into account the operational factors allowed us to demonstrate the logic of interactions in the main elements of the reported complex in the process of converting wind flow into the generated active and reactive power. We have shown the possibility of stable system work under changeable wind stream condition by regulating of the plant blade angle and with simultaneous varying of generator number of different types. All these are in great interest for project organizations and power producers.

Classification and Methods for Mathematical Description of Bank Risks

2009 ◽  
Vol 41 (2) ◽  
pp. 38-52
Author(s):  
Petr I. Bidyuk ◽  
Andrey .B. Basarab ◽  
Aidyn Sardar ogly Gasanov
Keyword(s):  
Mathematical Description ◽  
Bank Risks

Some aspects of the pedagogical model of constructive geometric modeling

2020 ◽  
Author(s):  
Denis Voloshinov ◽  
K. Solomonov ◽  
Lyudmila Mokretsova ◽  
Lyudmila Tishchuk
Keyword(s):  
Computer Graphics ◽  
Geometric Modeling ◽  
Educational Process ◽  
Educational Institutions ◽  
Software Systems ◽  
Teaching Methodology ◽  
Models Of Teaching ◽  
Software Product ◽  
The University

The application of constructive geometric modeling to pedagogical models of teaching graphic disciplines today is a promising direction for using computer technology in the educational process of educational institutions. The essence of the method of constructive geometric modeling is to represent any operation performed on geometric objects in the form of a transformation, as a result of which some constructive connection is established, and the transformation itself can be considered as a result of the action of an abstract cybernetic device. Constructive geometric modeling is a popular information tool for information processing in various applied areas, however, this tool cannot be appreciated without the presence of appropriate software systems and developed design techniques. Traditionally, constructive geometric modeling is used in the design of mechanical engineering, energy, aircraft and shipbuilding facilities, in architectural and design engineering. The need to study descriptive geometry at the university in recent years has something in common with the issues of mastering graphic packages of computer programs in the framework of the new discipline "Engineering and Computer Graphics". The well-known KOMPAS software product is considered the simplest and most attractive for training. It should be noted the important role of graphic packages in the teaching of geometric disciplines that require a figurative perception of the material by students. Against the background of a reduction in classroom hours, computer graphics packages are practically the only productive teaching methodology, successfully replacing traditional tools - chalk and blackboard.

The results of the study of the workers’ health according to the survey

2020 ◽  
pp. 793-793
Author(s):  
M. A. Fesenko ◽  
E. V. Zueva ◽  
E. V. Fedorova
Keyword(s):  
Medical Research ◽  
Working Conditions ◽  
Intermediate Stage ◽  
The State

The possibility of using the survey as an intermediate stage of assessing the state of working conditions and health of workers. It is concluded that this method is not applicable as an independent device but can be used with other methods of medical research.

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