Complex mathematical model for computer calculation of delivery and heat distribution in pipeline system

2011 ◽  
Author(s):  
I. V. Baranova ◽  
Y. V. Parfenenko ◽  
V. G. Nenja
Keyword(s):  
Mathematical Model ◽  
Computer Calculation ◽  
Pipeline System ◽  
Heat Distribution ◽  
Complex Mathematical Model

To the question of creating a complex mathematical model of a production system

2020 ◽  
Keyword(s):  
Mathematical Model ◽  
Hierarchical Structure ◽  
Production System ◽  
Quality Criterion ◽  
Controlling Parameter ◽  
Complex Mathematical Model

One of the approaches to the development of a complex mathematical model of a production system is considered. Keywords mathematical model; target subsystem; quality criterion; controlling parameter; hierarchical structure

Thermal Analysis of Expressway Considering Wind Effect

2013 ◽  
Vol 419 ◽  
pp. 895-904
Author(s):  
X. Cao ◽  
H. Miyashita ◽  
T. Kako ◽  
Z. Zhang ◽  
B. Song
Keyword(s):  
Mathematical Model ◽  
Thermal Analysis ◽  
Thermal Conduction ◽  
Computer Calculation ◽  
Basic Mechanism ◽  
Weather Data ◽  
Wind Effect ◽  
Fortran Language ◽  
Explicit Finite Difference ◽  
Explicit Finite Difference Method

This paper reports a method of thermal analysis of expressway and the results of analysis of four expressways currently used in Japan. The authors built a mathematical model based on the principle of thermal conduction. For the boundary conditions in this mathematical model the influence of solar radiation, wind and air temperature etc. are taken into consideration. Explicit finite difference method is used in the analysis. The authors made an analysis program in Fortran language. Four main expressways distributing from the northern to the southern in Japan are chosen as the objects of this study. The observed weather data of the hottest days experienced by these expressways during the past 30 years is input into the computer calculation. The basic mechanism of expressway temperature change and effect factors are illuminated. The results are reported and discussed.

scholarly journals Taking into account multi-axiality of loads on marine structures in their fatigue strength calculations

2019 ◽  
pp. 153-161
Author(s):  
Gennadiy Kryzhevich ◽  
Anatoliy Filatov
Keyword(s):  
Mathematical Model ◽  
Fatigue Strength ◽  
Axial Loading ◽  
Failure Criteria ◽  
Design Parameters ◽  
Optimal Assignment ◽  
Marine Structures ◽  
Fatigue Wear ◽  
Mathematical Simulations ◽  
Complex Mathematical Model

This paper studies marine structures made of steels and light alloys and exposed to cyclic operational loads. Stress-strain parameters of their joints were taken from mathematical simulations of loads and strains or from actual strain gauging data. The aim of this study is to develop recommendations on fatigue strength calculations: specifically, how to quite the complex mathematical model of multi-axial loading at critical structural points with fast fatigue wear in favour of a simplified stressstrain state description based on optimal assignment of design parameters (stresses) in fatigue failure criteria. Preferability of this approach depends on case-specific requirements to calculation accuracy and timeframes. Uniaxial description of stressed state instead of the three-axial one enables much faster calculation with acceptable drop in accuracy.

scholarly journals Mathematical modeling and algorithm for calculation of thermocatalytic process of producing nanomaterial

2021 ◽  
Vol 23 (3) ◽  
pp. 1590
Author(s):  
Bakhtiyar Ismailov ◽  
Zhanat Umarova ◽  
Khairulla Ismailov ◽  
Aibarsha Dosmakanbetova ◽  
Saule Meldebekova
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Solid Phase ◽  
Nonlinear Effects ◽  
Operating Characteristics ◽  
Laplace Transform Method ◽  
Transform Method ◽  
Wide Range ◽  
The Laplace Transform ◽  
Complex Mathematical Model

<p>At present, when constructing a mathematical description of the pyrolysis reactor, partial differential equations for the components of the gas phase and the catalyst phase are used. In the well-known works on modeling pyrolysis, the obtained models are applicable only for a narrow range of changes in the process parameters, the geometric dimensions are considered constant. The article poses the task of creating a complex mathematical model with additional terms, taking into account nonlinear effects, where the geometric dimensions of the apparatus and operating characteristics vary over a wide range. An analytical method has been developed for the implementation of a mathematical model of catalytic pyrolysis of methane for the production of nanomaterials in a continuous mode. The differential equation for gaseous components with initial and boundary conditions of the third type is reduced to a dimensionless form with a small value of the peclet criterion with a form factor. It is shown that the laplace transform method is mainly suitable for this case, which is applicable both for differential equations for solid-phase components and calculation in a periodic mode. The adequacy of the model results with the known experimental data is checked.</p>

Active thrust fluid-film bearings: Theoretical and experimental studies

2019 ◽  
Vol 234 (2) ◽  
pp. 261-273 ◽  
Author(s):  
Alexander Babin ◽  
Alexey Kornaev ◽  
Alexey Rodichev ◽  
Leonid Savin
Keyword(s):  
Mathematical Model ◽  
Position Control ◽  
Experimental Studies ◽  
Axial Loading ◽  
Life Time ◽  
Fluid Film ◽  
Thrust Bearings ◽  
Active Fluid ◽  
Rotor Bearing ◽  
Complex Mathematical Model

Research in the field of active fluid-film bearing has been recently getting more and more attention, integration of control systems becoming one of the most promising means of enhancement of rotor-bearing nodes' characteristics. It has been determined that the vast majority of papers published on active fluid-film bearing only consider radial bearings, and very few focus on thrust bearings. This lack of attention along with the obvious necessity to fill the said gap has triggered the present research. In cases of rotor machines that experience extensive axial loading due to various reasons, e.g. various turbine engines (aero and spacecraft) and hydraulic pumps (crude oil extraction facilities), such research could prove the feasibility of application of a control system to significantly increase the performance of the whole machine. Moreover, extensive wear during start up and shut down could be eliminated by means of rotor position control, thus life time of a rotor-bearing system could be significantly increased. The present paper features a complex mathematical model of an active thrust fluid-film bearing with a central feeding orifice, a developed test rig designed to verify the presented mathematical model allowing a series of numerical tests to be carried out. Numerical studies focus on the hypothesis of a possibility to use active control in thrust bearings to decrease power loss due to friction and extensive axial vibrations by means of identification of an energy efficient area of axial gaps based on the lubrication regime and its maintenance by means of application of controlled lubrication principles.

scholarly journals Development of Complex Mathematical Model of Light Naphtha Isomerization and Rectification Processes

2014 ◽  
Vol 10 ◽  
pp. 236-243 ◽  
Author(s):  
Viacheslav A. Chuzlov ◽  
Nikita V. Chekantsev ◽  
Emilia D. Ivanchina
Keyword(s):  
Mathematical Model ◽  
Light Naphtha ◽  
Complex Mathematical Model

Research on Heat Distribution in a Thermal Insulation Space and a Kind of Evaluation Involving Heat-Distribution and Valid Heating-Area

2013 ◽  
Vol 444-445 ◽  
pp. 1427-1433
Author(s):  
Hong Yang Jin ◽  
Zhi Hua Chen ◽  
Lang Li
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Standard Deviation ◽  
Thermal Insulation ◽  
Transfer Equation ◽  
Heating Process ◽  
Heat Distribution ◽  
Heat Transfer Equation ◽  
Heat Transmission

Considering that food always be spoiled in an oven, an analysis of the heat distribution of an object (pan) in a thermal insulation space has been done. The analysis based on the characteristics of heat transmission in an oven. A mathematical model is designed to illustrate the heating process. Specifically, in order to monitor the temperature of the object, pdetool in MATLAB is used to solve the heat transfer equation. Then to evaluate how an object performs in the oven, a method of standard deviation has been introduced. For the efficiency, valid heating area should also be considered. Thus an evaluation is made to choose a most preferring pan, which is balanced between heat distribution and valid heating area (number of pans). The experiment shows that shapes would devote much in performance. It is also demonstrated that there is a certain shape that can be most suitable to be a pan.

scholarly journals Micropolar fluid between two coaxial cylinders (numerical approach)

2021 ◽  
pp. 12-12
Author(s):  
Dusko Salemovic ◽  
Aleksandar Dedic ◽  
Bosko Jovanovic
Keyword(s):  
Mathematical Model ◽  
Symmetry Axis ◽  
Numerical Approach ◽  
Variable Coefficients ◽  
Constant Angular Velocity ◽  
Coaxial Cylinders ◽  
Complex Mathematical Model ◽  
Two Phases ◽  
Physical Analogy ◽  
The Continuum

The paper describes the flow of a suspension which is a mixture of two phases: liquid and solid granules. The continuum model with microstructure is introduced, which involves two independent kinematic quantities: the velocity vector and the micro-rotation vector. The physical analogy is based on the movement of the suspension between two coaxial cylinders. The inner cylinder is stationary and the outer one rotates with constant angular velocity. This physical analogy enabled a mathematical model in a form of two coupled differential equations with variable coefficients. The aim of the paper is to present the numerical aspect of the solution for this complex mathematical model. It is assumed that the solid granules are identically oriented and that under the influence of the fluid they move translationally or rotate around the symmetry axis but the direction of their symmetry axes does not change. The solution was obtained by the ordinary finite difference method, and then the corresponding sets of points (nodes) were routed by interpolation graphics.

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