Numerical analysis of temperature field in a thawing embankment in permafrost

1988 ◽  
Vol 25 (1) ◽  
pp. 163-166 ◽  
Author(s):  
Mu Shen
Keyword(s):  
Mathematical Model ◽  
Temperature Field ◽  
Heat Conduction ◽  
Numerical Analysis ◽  
Finite Elements ◽  
Measured Data ◽  
Two Dimensional ◽  
Nonlinear Mathematical Model ◽  
Permafrost Thawing ◽  
Good Agreement

The objective of this paper is to present a numerical analysis by finite elements of a two-dimensional nonlinear mathematical model for heat conduction with phase change in a thawing embankment in permafrost. The calculated results are compared with actual measured data, and good agreement is obtained. All calculations were carried out on a personal computer. Key words: permafrost, thawing, embankment, temperature field, numerical analysis.

scholarly journals Nonlocal Thermodynamics: Mathematical Model of Two-Dimensional Thermal Conductivity

2021 ◽  
Vol 321 ◽  
pp. 03005
Author(s):  
George Kuvyrkin ◽  
Inga Savelyeva ◽  
Daria Kuvshinnikova
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Heat Conduction ◽  
Numerical Solution ◽  
Complex Structure ◽  
Modern World ◽  
Nonlocal Term ◽  
Material Structure ◽  
Two Dimensional ◽  
Differential Heat

Nonlocal models of thermodynamics are becoming more and more popular in the modern world. Such models make it possible to describe materials with a complex structure and unique strength and temperature properties. Models of nonlocal thermodynamics of a continuous medium establish a relationship between micro and macro characteristics of materials. A mathematical model of thermal conductivity in nonlocal media is considered. The model is based on the theory of nonlocal continuum by A.K. Eringen. The interaction of material particles is described using local and nonlocal terms in the law of heat conduction. The nonlocal term describes the effect of decreasing the influence of the surrounding elements of the material structure with increasing distance. The effect of nonlocal influence is described using the standard non-locality function based on the Gaussian distribution. The nonlocality function depends on the distance between the elements of the material structure. The mathematical model of heat conduction in a nonlocal medium consists of an integro-differential heat conduction equation with initial and boundary conditions. A numerical solution to the problem of heat conduction in a nonlocal plate is obtained. The numerical solution of a two-dimensional problem based on the finite element method is described. The influence of nonlocal effects and material parameters on the thermal conductivity in a plate under highintensity surface heating is analyzed. The importance of nonlocal characteristics in modelling the thermodynamic behaviour of materials with a complex structure is demonstrated.

scholarly journals The Theory and Demonstration of the Solid-Fluid Transformation of Ice Water

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yong-Yan Wang ◽  
Xi-Yan Fan ◽  
Nan Qin ◽  
Jian-Guang Li ◽  
Chuan-Qi Su
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Special Geometry ◽  
Ice Water ◽  
Good Agreement

In this paper, a mathematical model for describing the solid-fluid transformation of ice water is put forward based on the special geometry cases. The correctness of the obtained model is verified through comparison with numerical analysis and experiments. The good agreement indicates that the obtained model is available for the study of the solid-fluid transformation of ice water. The theory derived in this paper lays a foundation for the research of solid-fluid transformation phenomena of other materials and may have important applications in engineering areas such as rheology, creep, and instability of materials.

A Numerical Method for Heat Conduction Problems

1974 ◽  
Vol 96 (3) ◽  
pp. 307-312 ◽  
Author(s):  
M. J. Reiser ◽  
F. J. Appl
Keyword(s):  
Exact Solution ◽  
Heat Conduction ◽  
Steady State ◽  
Numerical Analysis ◽  
Temperature Gradient ◽  
Singular Integral ◽  
Integral Method ◽  
Two Dimensional ◽  
Convection Boundary ◽  
Steady State Heat

A singular integral method of numerical analysis for two-dimensional steady-state heat conduction problems with any combination of temperature, gradient, or convection boundary conditions is presented. Excellent agreement with the exact solution is illustrated for an example problem. The method is used to determine the solution for a fin bank with convection.

Deregulation of p53-dependent microRNAs: the results of mathematical modeling

2017 ◽  
Vol 12 (1) ◽  
pp. 151-175 ◽  
Author(s):  
О.Ф. Воропаева ◽  
O.F. Voropaeva
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Numerical Analysis ◽  
Neurodegenerative Disease ◽  
Numerical Investigation ◽  
Tumor Markers ◽  
Critical Properties ◽  
Laboratory Studies ◽  
The Mathematical Model ◽  
Good Agreement

The mathematical model of the dynamics of the tumor markers network p53–Mdm2–microRNA for microRNA class with a direct positive connection with p53 was formulated. Numerical investigation of the microRNA functioning in conditions of the deregulation of p53 and p53–Mdm2-network was carried out. The deregulation of microRNA in detail was studied. The situations in which p53, its inhibitor Mdm2 and microRNAs exhibit critical properties for the patient's status and can be identified as diagnostic markers of cancer and neurodegenerative disease were studied. The results of numerical analysis are in good agreement with the data of clinical and laboratory studies of known microRNAs.

A Real-Time Mathematical Model for the Two-Dimensional Temperature Field of Petroleum Coke Calcination in Vertical Shaft Calciner

JOM ◽  
2016 ◽  
Vol 68 (8) ◽  
pp. 2149-2159 ◽  
Author(s):  
Jin Xiao ◽  
Jindi Huang ◽  
Qifan Zhong ◽  
Fachuang Li ◽  
Hongliang Zhang ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Temperature Field ◽  
Real Time ◽  
Petroleum Coke ◽  
Vertical Shaft ◽  
Two Dimensional

Prediction of Rail Profile Wear with the Increase of Vehicle Speed

2013 ◽  
Vol 716 ◽  
pp. 659-662
Author(s):  
Dong Hyong Lee ◽  
Jeong Won Seo ◽  
Seok Jin Kwon ◽  
Ha Young Choi
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Boundary Conditions ◽  
Rolling Contact ◽  
Finite Elements Method ◽  
Vehicle Speed ◽  
Two Dimensional ◽  
Contact Wear ◽  
Rail Wear ◽  
Finite Elements Model

A method to simulate rolling contact wear in a rail surface was developed using the finite elements method and numerical analysis. A two-dimensional finite elements model was used in order to reduce the calculation time and boundary conditions to prevent excessive deformation of a wheel and a rail were applied. A numerical analysis of rail wear at rolling contact was predicted using the Archards equation. In addition, the characteristics of rail wear with the increasing speed of vehicle were analyzed. Results show that there was not a large difference in the depths of wear on the rail head with increasing vehicle speed, but the wear on the rail gauge corner increased with increasing vehicle speed.

Study of viscosity on the fission dynamics of the excited nuclei 228U produced in 19F + 209Bi reactions

2015 ◽  
Vol 24 (07) ◽  
pp. 1550052 ◽  
Author(s):  
H. Eslamizadeh
Keyword(s):  
Experimental Data ◽  
Symmetry Axis ◽  
Measured Data ◽  
Total Spin ◽  
Langevin Equations ◽  
Two Dimensional ◽  
Excitation Energies ◽  
Fission Fragments ◽  
Excited Nuclei ◽  
Good Agreement

A two-dimensional (2D) dynamical model based on Langevin equations was applied to study the fission dynamics of the compound nuclei 228 U produced in 19 F + 209 Bi reactions at intermediate excitation energies. The distance between the centers of masses of the future fission fragments was used as the first dimension and the projection of the total spin of the compound nucleus onto the symmetry axis, K, was considered as the second dimension in Langevin dynamical calculations. The magnitude of post-saddle friction strength was inferred by fitting measured data on the average pre-scission neutron multiplicity for 228 U . It was shown that the results of calculations are in good agreement with the experimental data by using values of the post-saddle friction equal to 6–8 × 1021 s -1.

An Application for Analysis of Temperature during Cold Rolling

2013 ◽  
Vol 199 ◽  
pp. 131-136
Author(s):  
Olena Yevtushenko
Keyword(s):  
Mathematical Model ◽  
Plastic Deformation ◽  
Temperature Field ◽  
Numerical Analysis ◽  
Cold Rolling ◽  
Partition Ratio ◽  
Transient Temperature ◽  
Heat Partition ◽  
Transient Temperature Field ◽  
The Mathematical Model

The problem of software creation for the analysis of transient temperature field in cold rolling of metals is under consideration. Firstly, the mathematical model of the process of heating the strip and rolls at cold rolling it is proposed. This model assumes that the generation of heat during the rolling takes place due to friction on the contact surface of the rolls and the strip as well as plastic deformation of the strip material. Next, some fragments of created application for the purpose of an overall numerical analysis of heat partition ratio between the rolls and a strip as well as the temperature in any point of these elements are presented.

scholarly journals Experimental, analytical and numerical analysis of voltage distribution along the cap-and-pin insulators

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Mladen Banjanin
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Electrostatic Field ◽  
Field Model ◽  
Experimental Measurements ◽  
Voltage Distribution ◽  
Specialized Software ◽  
The Earth ◽  
Good Agreement ◽  
Linear Voltage

This paper deals with the experimental, analytical and numerical analysis of voltage distribution along the cap-and-pin insulators. Five different insulators strings are analyzed, consisting of two, three, four, five and six cap-and-pin U40BL glass disc insulators. Experimental measurements are performed in the high voltage laboratory at the Faculty of Electrical Engineering East Sarajevo. Measurement of the voltage distribution along the disc insulators is performed by using measuring sphere gap. Analytical calculations are performed by using mathematical model which considers parasite self-capacitances of disc insulators, as well as their parasite capacitances to the earth and to the phase conductor. Calculations of the parasite capacitances values are performed and optimum values which lead to the minimum difference between measured and calculated results are suggested. Numerical analyses of the non-linear voltage distribution are performed by using electrostatic field model in software Comsol Multyphisics. 2D axisymmetric models of the cap-and-pin insulators are developed. Despite the measuring configuration is not suitable for numerical analysis, relatively good agreement between the measured results and results calculated by using specialized software are achieved.

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