scholarly journals SIMULATION OF NON-STATIONARY HEAT EXCHANGE OF ELECTRO-CONDUCTIVE LIQUID IN A SPHERICAL LAYER

2018 ◽  
Author(s):  
S. V. Solov'ev ◽  
Keyword(s):  
Heat Exchange ◽  
Spherical Layer ◽  
Conductive Liquid ◽  
Stationary Heat

Simulation of electrically conductive liquid convection in a spherical layer when heat is applied to the inner sphere

2019 ◽  
Author(s):  
С.В. Соловьев
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Magnetic Induction ◽  
Spherical Layer ◽  
Gravity Vector ◽  
Joule Dissipation ◽  
Conductive Liquid ◽  
Nusselt Numbers

Представлены результаты численного моделирования конвективного теплообмена электропроводящей жидкости между концентрическими сферами при подводе тепла к внутренней сфере. Исследовано влияние числа Грасгофа и джоулевой диссипации на структуру течения жидкости, поля температуры, магнитной индукции и распределение локальных чисел Нуссельта. Получено уравнение подобия теплообмена, когда ускорение свободного падения направлено к центру сферического слоя. The Boussinesq approximation is used for modelling a large class of problems of convective heat transfer in spherical concentric layers in which the gravity vector is directed vertically downwards. But for problems of geophysics and astrophysics there is a fundamental difference, the gravity vector is directed along the radius to the center of the spherical layer. Therefore, the study of convective heat transfer in spherical layers, when the vector of gravitational acceleration is directed along the radius to the center of the spherical layer, is of independent interest. In this paper, the influence of the Grashof number, the Joule dissipation heat on the fluid flow structure, temperature field, magnetic induction, and the distribution of Nusselt numbers when heat is applied from below are studied. To solve the problem, the finite element method is used. In a dimensionless formulation, the problem is solved taking into account both the heat of the Joule dissipation, magnetic, inertial, viscous and lifting forces in a spherical coordinate system and the symmetry in longitude. The stationary fields of temperature, stream functions, vortex strength, radial and meridional components of magnetic induction and the distribution of local Nusselt numbers of electro conductive liquid in a concentric spherical layer for different Grashof numbers with and without accounting for the heat of Joule dissipation are obtained when heat is applied to the inner sphere. Two critical values of the Grashof number are numerically determined. The equation of heat exchange similarity is obtained, when the acceleration of gravity is directed to the center of the spherical layer. The mathematical model and the presented results may be useful for the study of convective heat exchange of electrically conducting fluid in space technologies and in the geophysical and astrophysical problems.

scholarly journals HEAT EXCHANGE OF ELECTRIC CONDUCTIVE LIQUID AT LARGE VALUES OF THE REYNOLD'S MAGNETIC NUMBER

2021 ◽  
pp. 12-22
Author(s):  
С.В. Соловьев ◽  
Т.С. Соловьева
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Heat Exchange ◽  
Spherical Layer ◽  
Magnetic Reynolds Number ◽  
Electrically Conductive ◽  
Conductive Liquid ◽  
Nusselt Numbers

Представлены результаты численного моделирования нестационарного конвективного теплообмена и магнитной гидродинамики электропроводной жидкости в сферическом слое при граничных условиях для температуры первого рода. Исследовано влияние величины магнитного числа Рейнольдса на эволюцию структуры течения жидкости, поле температуры, магнитной индукции и распределение чисел Нуссельта. The results of numerical simulation of unsteady convective heat transfer and magneto hydrodynamics of an electrically conductive fluid in a spherical layer under boundary conditions for a temperature of the first kind are presented. The influence of the value of the magnetic Reynolds number on the evolution of the structure of the fluid flow, the field of temperature, magnetic induction and the distribution of Nusselt numbers is investigated.

Inductive heating of fluidized beds: Mobile versus stationary heat exchange elements

2018 ◽  
Vol 37 (5) ◽  
pp. 652-663 ◽  
Author(s):  
Vesselin V. Idakiev ◽  
Andreas Bück ◽  
Lothar Mörl ◽  
Evangelos Tsotsas
Keyword(s):  
Heat Exchange ◽  
Fluidized Beds ◽  
Inductive Heating ◽  
Stationary Heat

scholarly journals Study on non-stationary heat exchange in combined packages of water-resistant protective clothing of firefighters

2020 ◽  
Vol 64 (4) ◽  
pp. 467-476
Author(s):  
A. I. Ol’shanskii ◽  
R. V. Okunev ◽  
A. M. Gusarov
Keyword(s):  
Thermal Conductivity ◽  
Heat Exchange ◽  
Protective Clothing ◽  
Thermal Contact ◽  
Exchange Process ◽  
Toxic Substances ◽  
Nonlinear Transport ◽  
Stationary Heat ◽  
Technical Requirements ◽  
Linearization Methods

The results of research of non-stationary heat exchange in combined packages intended for creation of special water- and heat-resistant protective clothing of firefighters from dangerous and harmful factors during emergency rescue and other urgent works, with participation of non-toxic substances, acid solutions, alkalis, oil and petroleum products, liquid toxic substances, as well as during operation in water with temperature from 0 to 70 °С are presented. The stability of clothing material packs has been investigated as a transient heat exchange process in a multilayer plate with ideal thermal contact at the joints of the layers. The unlimited plate is heated on both sides under different heat exchange conditions according to Newton’s Law, with constant action of the heat source on one of the surfaces of the hot liquid contacting through the waterproof thin surface. Second surface of the plate interacts with external medium, temperature of which varies according to linear law. At solving the equation of non-stationary thermal conductivity with nonlinear transport coefficients, linearization methods are used based on the approximation of nonlinear coefficients, such that nonlinear equations become approximately linear. The entire heat transfer process is divided into a plurality of small-time intervals within which the transfer coefficients are constant. The zonal method of investigation of non-stationary thermal conductivity in clothing packages establishes equations for calculation of temperature, densities of thermal flows, distribution of temperature across thickness of clothing packages. It has been shown that under accepted calculation simplifications, parameter values are well consistent with the experiment. The composition of the clothing package is proposed, which meets the technical requirements of TУ BY 101114857.082-2015 “Personal Protective Kits”.

scholarly journals HEAT EXCHANGE OF ELECTRIC CONDUCTIVE LIQUID IN THE SUPPLY OF HEAT TO THE INNER SURFACE OF THE SPHERICAL LAYER AT SMALL VALUES OF THE REYNOLD'S MAGNETIC NUMBER

2021 ◽  
pp. 35-42
Author(s):  
С.В. Соловьев
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Spherical Layer ◽  
Magnetic Reynolds Number ◽  
Joule Dissipation ◽  
Unsteady Heat Transfer ◽  
Electrically Conductive ◽  
Conductive Liquid ◽  
Nusselt Numbers ◽  
Inner Surface

Представлены результаты численного моделирования нестационарного теплообмена и магнитной гидродинамики электропроводной жидкости в сферическом слое. Исследовано влияние малых значений магнитного числа Рейнольдса и теплоты джоулевой диссипации на эволюцию структуры течения жидкости, поле температуры, магнитной индукции и распределение чисел Нуссельта. The results of numerical simulation of unsteady heat transfer and magneto hydrodynamics of an electrically conductive fluid in a spherical layer are presented. The influence of small values of the magnetic Reynolds number and the heat of Joule dissipation on the evolution of the structure of the fluid flow, the field of temperature, magnetic induction and the distribution of Nusselt numbers is investigated.

Temperature State of the Anisotropic Spherical Layer During Convective Heat Exchange with the Environment

2019 ◽  
pp. 40-55
Author(s):  
V.S. Zarubin ◽  
V.V. Leonov ◽  
V.S. Jr. Zarubin
Keyword(s):  
Heat Conduction ◽  
Heat Exchange ◽  
Convective Heat ◽  
Outer Surface ◽  
Heat Conduction Problem ◽  
Convective Heat Exchange ◽  
Spherical Layer ◽  
Coating Material ◽  
Temperature State ◽  
Heat Shielding

The paper focuses on the process of steady heat conduction in a spherical layer of a heat-shielding coating made of anisotropic material. The inner surface of the layer is ideally heat-insulated but its outer surface is exposed to heating by convective heat exchange with the environment, the temperature of which varies along this surface. Based on the obtained solution of the linear heat conduction problem, we quantitatively assessed the influence of the degree of anisotropy of the coating material, its relative thickness, intensity of convective heat transfer, and uneven distribution of ambient temperature on the equalization of temperature distribution in the spherical layer. The results obtained can be used to select the characteristics of an anisotropic coating material in order to reduce the temperature of the outer surface of the spherical layer in the zone of the most intense heating.

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