Heat Convection from a Horizontal Cylinder Rotating in a Quiescent Fluid

1986 ◽  
Vol 10 (3) ◽  
pp. 141-152
Author(s):  
H.M. Badr ◽  
S.M. Ahmed
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Horizontal Cylinder ◽  
Heat Transfer Process ◽  
Two Dimensional ◽  
Two Dimensional Flow ◽  
Boussinesq Fluid ◽  
The Mathematical Model ◽  
Quiescent Fluid

The aim of this work is a theoretical investigation to the problem of heat transfer from an isothermal horizontal cylinder rotating in a quiescent fluid. The study is based on the solution of the conservation equations of mass, momentum and energy for two-dimensional flow of a Boussinesq fluid. The effects of the parameters which influence the heat transfer process namely the Reynolds number and Grashof number are considered while the Prandtl number is held constant. Streamline and isotherm patterns are obtained from the mathematical model and the results are compared with previous experimental data. A satisfactory agreement was found.

Finite Element Thermal Analysis on Heat Transfer Performance of Rectangular Micro – Groove Flat Heat Pipe

2013 ◽  
Vol 721 ◽  
pp. 456-460
Author(s):  
Yi Bing Liu
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Thermal Analysis ◽  
Heat Pipe ◽  
Heat Transfer Process ◽  
Pipe Surface ◽  
Iterative Computation ◽  
Flow And Heat Transfer ◽  
The Mathematical Model ◽  
Flat Heat Pipe

Having fully considered the influence of gas-liquid interfacial friction on the heat transfer characteristics of heat pipe within the channel, the mathematical model of the flow and heat transfer process in the Rectangular Micro-groove flat heat pipe is established. The simulation is performed by using thermal analysis software ANSYS. The iterative computation values of the center point temperature of the heat pipe surface being compared with the simulation results, the error is only 5.27% and the two are basically the same values, which shows that the mathematical model has a guiding significance on the analysis of heat pipe theory.

Analysis of Thermal Conduction Effects on Thermoelastic Temperature Measurements for Composite Materials

1992 ◽  
Vol 59 (3) ◽  
pp. 552-558 ◽  
Author(s):  
S. A. Dunn
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Composite Materials ◽  
Surface Stress ◽  
Thermal Conduction ◽  
Dissimilar Materials ◽  
Stress Fields ◽  
Temperature Changes ◽  
The Mathematical Model

Measurement of the temperature changes which occur as a body undergoes a change in stress is becoming a widely used technique for the analysis of surface stress fields. In this paper, an investigation into the effects of thermal conduction on surface thermoelastic temperature changes for composite materials is reported. A mathematical model which shows the effects of thermal conduction is developed, and the results from this model are compared with experimental data. The mathematical model is then extended to solve for heat transfer between two thermally dissimilar materials. It is shown how this model can be used to account for the effects of a surface epoxy layer on the observed thermoelastic temperature changes.

scholarly journals Simulation of Electromagnetic-Acoustic Heating of the Oil Layer in Laboratory Conditions

2021 ◽  
Vol 16 (1) ◽  
pp. 109-116
Author(s):  
Gulnara R. Izmailova
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
High Frequency ◽  
Additional Term ◽  
Oil Reservoir ◽  
Combined Effects ◽  
Physical Processes ◽  
The Mathematical Model ◽  
Account Heat

This paper describes an experiment to study the combined effects of high-frequency electromagnetic and acoustic fields on a model of an oil reservoir. A mathematical model is described that describes the physical processes that occur in the reservoir. The heat equation takes into account heat transfer with the environment by introducing an additional term. The largest discrepancy between theoretical and experimental data does not exceed 28%. Qualitative coincidence of theoretical and experimental curves indicates the adequacy of the mathematical model.

scholarly journals EXPERIMENTAL STUDIES OF HEAT EXCHANGE DURING WATER COOLING AND STEAM CONDENSATION IN DEMOVER RADIATOR SECTIONS

2021 ◽  
Vol 1 (38) ◽  
pp. 107-114
Author(s):  
V. Mogila ◽  
M. Kovtanets ◽  
M. Morneva
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Cooling System ◽  
Experimental Studies ◽  
Road Transport ◽  
Thermal Calculation ◽  
Mode Of Operation ◽  
Simulation Results ◽  
The Mathematical Model

The Department of Railwayand Road Transport, lift and care system of Volodymyr Dahl East Ukrainian National University, an energy-saving cooling system for diesel locomotives using phase transitions of the coolant has been developed. The proposed cooling system allows to maintain constant optimal temperatures of cooling objects at ambient temperatures ± 40 ºC and in any mode of operation of the diesel engine. For thermal calculation of the radiator section operating in the mode of the steam condenser, the mathematical model of process of heat transfer from steam to walls of a flat tube at condensation is developed that considers geometrical features of section of a tube. The adequacy of this mathematical model is verified by comparing the simulation results with the obtained experimental data. During the tests, the outlet water temperature, inlet and outlet air temperature, and air pressure in front of and behind the radiator were measured. Having the values of wall temperature, steam temperature and condensate, knowing the value of steam consumption and the experimental heat transfer coefficient, it becomes possible to verify the adequacy of the mathematical model by comparing the simulation results with the obtained experimental data. Schemes of bench equipment, test methods, experimental planning and basic calculation dependences required for testing serial radiator sections of a locomotive in the standard mode of operation and in the mode of steam condensers are presented.

The Analysis of Non-Fourier Heat Transfer Mechanism on Thermal Conductivity for Nanofluids

2007 ◽  
Author(s):  
Jurij Avsec ◽  
Maks Oblak
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Conductivity ◽  
Mathematical Model ◽  
Analytical Calculation ◽  
Heat Transfer Mechanism ◽  
Influence Of Temperature ◽  
The Mathematical Model ◽  
Brown Motion ◽  
Good Agreement

The paper features the mathematical model representing the analytical calculation of thermal conductivity for nanofluids. The mathematical model was developed on the basis of statistical nano-mechanics. We have made the detailed analysis of the influence of temperature dependence on thermal conductivity for nanofluids. On this basis are taken into account the influences such as formation of nanolayer around nanoparticles, the Brown motion of solid nanoparticles and influence of diffusive-ballistic heat transport. The analytical results obtained by statistical mechanics are compared with the experimental data and they show relatively good agreement.

scholarly journals NON-UNIFORM SUSPENDED SEDIMENTS UNDER WAVES

1988 ◽  
Vol 1 (21) ◽  
pp. 84
Author(s):  
Aronne Armanini ◽  
Piero Ruol
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Mathematical Model ◽  
Mathematical Formulation ◽  
Suspended Sediments ◽  
Two Dimensional ◽  
Different Diameters ◽  
Wave Boundary ◽  
The Mathematical Model ◽  
Dimensional Wave

An original mathematical formulation for suspended sediments in a two-dimensional wave boundary layer is presented. The model accounts for non-immediate adaptation of sediments to the hydrodinamic conditions, and allows to include the effect of sorting of the different diameters considered. The mathematical model is numerically solved through a finite difference scheme. It is suitable that results compare favourably with experimental data by Staub et alii.

scholarly journals Numerical modeling of heat flow between three-dimensional regions in contact problems

2018 ◽  
Vol 157 ◽  
pp. 08010
Author(s):  
Tomasz Skrzypczak ◽  
Ewa Węgrzyn-Skrzypczak
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Numerical Modeling ◽  
Three Dimensional ◽  
Contact Problems ◽  
Heat Transfer Process ◽  
Heat Diffusion ◽  
The Finite Element Method ◽  
Three Dimensional Objects ◽  
The Mathematical Model

The method of numerical modeling of heat transfer between three-dimensional objects being in contact is described in the paper. Presented approach is based on the finite element method (FEM) with independent spatial discretization of considered regions. The gap between external surfaces of the interacting objects has variable width and is filled with gas or liquid. The medium in the gap introduces thermal resistance into heat transfer process. The mathematical model of considered problem is based on the equation of heat diffusion supplemented by the appropriate initial and boundary conditions. The deformations of the regions resulting from the thermally dependent changes of their volumes are also included in the model. The results of numerical simulations are presented and discussed.

Design of the Blast Furnace Wall Structure Made of Efficient Materials. Part 4. Calculation Examples

2020 ◽  
Vol 786 (11) ◽  
pp. 30-34
Author(s):  
A.M. IBRAGIMOV ◽  
◽  
L.Yu. GNEDINA ◽  
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Blast Furnace ◽  
Boundary Value Problems ◽  
Transfer Process ◽  
Rational Design ◽  
Boundary Value ◽  
Heat Transfer Process ◽  
Furnace Wall ◽  
Time Interval

This work is part of a series of articles under the general title The structural design of the blast furnace wall from efficient materials [1–3]. In part 1, Problem statement and calculation prerequisites, typical multilayer enclosing structures of a blast furnace are considered. The layers that make up these structures are described. The main attention is paid to the lining layer. The process of iron smelting and temperature conditions in the characteristic layers of the internal environment of the furnace is briefly described. Based on the theory of A.V. Lykov, the initial equations describing the interrelated transfer of heat and mass in a solid are analyzed in relation to the task – an adequate description of the processes for the purpose of further rational design of the multilayer enclosing structure of the blast furnace. A priori the enclosing structure is considered from a mathematical point of view as the unlimited plate. In part 2, Solving boundary value problems of heat transfer, boundary value problems of heat transfer in individual layers of a structure with different boundary conditions are considered, their solutions, which are basic when developing a mathematical model of a non-stationary heat transfer process in a multi-layer enclosing structure, are given. Part 3 presents a mathematical model of the heat transfer process in the enclosing structure and an algorithm for its implementation. The proposed mathematical model makes it possible to solve a large number of problems. Part 4 presents a number of examples of calculating the heat transfer process in a multilayer blast furnace enclosing structure. The results obtained correlate with the results obtained by other authors, this makes it possible to conclude that the new mathematical model is suitable for solving the problem of rational design of the enclosing structure, as well as to simulate situations that occur at any time interval of operation of the blast furnace enclosure.

Systems Actuated by Shape Memory Alloys: Identification and Modeling

2021 ◽  
Vol 1 (2) ◽  
pp. 12-20
Author(s):  
Najmeh Keshtkar ◽  
Johannes Mersch ◽  
Konrad Katzer ◽  
Felix Lohse ◽  
Lars Natkowski ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Numerical Simulations ◽  
Shape Memory ◽  
Transfer Equation ◽  
Mechanical Parameters ◽  
Heat Transfer Equation ◽  
The Mathematical Model

This paper presents the identification of thermal and mechanical parameters of shape memory alloys by using the heat transfer equation and a constitutive model. The identified parameters are then used to describe the mathematical model of a fiber-elastomer composite embedded with shape memory alloys. To verify the validity of the obtained equations, numerical simulations of the SMA temperature and composite bending are carried out and compared with the experimental results.

Application of a Bubble-Induced Turbulence Model to Subcooled Boiling in a Vertical Pipe

1999 ◽  
Author(s):  
Mahmut D. Mat ◽  
Yüksel Kaplan ◽  
Olusegun J. Ilegbusi
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Liquid Phase ◽  
Turbulence Model ◽  
Transport Equations ◽  
Subcooled Boiling ◽  
Vertical Pipe ◽  
Void Fractions ◽  
Turbulence Production ◽  
The Mathematical Model

Abstract Subcooled boiling of water in a vertical pipe is numerically investigated. The mathematical model involves solution of transport equations for vapor and liquid phase separately. Turbulence model considers the turbulence production and dissipation by the motion of the bubbles. The radial and axial void fractions, temperature and velocity profiles in the pipe are calculated. The estimated results are compared to experimental data available in the literature. It is found that while present study satisfactorily agrees with experimental data in the literature, it improves the prediction at lower void fractions.

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