scholarly journals Comparison of analytical methods and numerical methods in modeling the physical phenomenon of heat conduction with free radiation

2021 ◽  
Vol 2102 (1) ◽  
pp. 012015
Author(s):  
C Nolasco Serna ◽  
N Afanador Garcia ◽  
G Guerrero Gómez
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Fluid Mechanics ◽  
Numerical Method ◽  
Materials Science ◽  
Physical Phenomenon ◽  
Heat Transfer Process ◽  
Percentage Error ◽  
Temperature Function ◽  
Physical Phenomena

Abstract The development of mathematical setting for modeling heat conduction phenomena in the presence of radioactive effects is well known. The importance in the study of heat conduction in relation to radioactive effects is relevant in several engineering applications such as combustion, materials science, fluid mechanics and other areas. This research is based on the mathematical model of the heat equation to study the physical phenomenon of heat transfer along a metal bar with slightly insulated sides with the effect of free radiation. To calculate the temperature function that allows modeling the heat transfer process along the bar, the Fourier series solution is constructed step by step, in addition an alternative method of calculating the temperature by using the explicit numerical method is given. The calculation of the temperature along the bar is compared by analytical and numerical method by computing the percentage error and different temperature profiles are plotted to verify the fit of the two approaches. The methods developed throughout the research can be extended to other types of physical phenomena that are useful in related research and in education in engineering subjects such as fluid mechanics and heat transfer.

Call for Nominations – The Nusselt–Reynolds Prize Sponsored by Assembly of World Conferences on Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics

2000 ◽  
Vol 402 ◽  
pp. 382-382
Author(s):  
Nobuhide Kasagi
Keyword(s):  
Heat Transfer ◽  
Fluid Mechanics ◽  
Design Theory ◽  
Experimental Studies ◽  
Heat Transfer Fluid ◽  
World Conference ◽  
Experimental Heat ◽  
Technological Advances ◽  
Visualization Techniques ◽  
Physical Phenomena

The Nusselt–Reynolds Prize has been established by the Assembly of World Conferences to commemorate outstanding contributions by Wilhelm Nusselt and Osborne Reynolds as experimentalists, researchers, educators, and authors. As many as three prizes may be bestowed at every World Conference, one in each of the areas of heat transfer, fluid mechanics, thermodynamics, or any combination of these.The prize will be bestowed for outstanding scientific and engineering contributions and eminent achievements in the fields of heat transfer, fluid mechanics, and thermodynamics through (1) experimental studies and analytical/numerical extension of the measurements, (2) development of experimental techniques, visualization techniques, and/or instrumentation, and/or (3) development of design theory (that needs experimental data) and theory-based experimental correlations. These contributions should yield a deeper insight into physical phenomena involved or should yield significant technological advances. In addition to research, the awardee(s) should have made outstanding contributions to the field through teaching, design, or a combination of such activities. The prize is based on achievement through publications or through the application of the science or art. Nationality, age, sex, and society membership will not be considered when evaluating qualifications of candidates. A candidate must be living at the time of designation as a recipient of the prize.The prize consists of a bronze plaque, and engrossed certificate, and an honorarium. The prize is administered by the Prize Board. The deadline for accepting nominations for the Prize is February 2, 2000. The prize will be awarded at the Fifth World Conference during September 24–28, 2001 in Thessaloniki, Greece where the prize winners will also present plenary lectures on their subjects.Nominators can obtain further information and download the nomination form from a webpage at http://www.thtlab.t.u-tokyo.ac.jp/N-Rprize.html/.

Application of the Conservation Element and Solution Element Method in Numerical Modeling of Three-Dimensional Heat Conduction With Melting and/or Freezing

2004 ◽  
Vol 126 (6) ◽  
pp. 937-945 ◽  
Author(s):  
Anahita Ayasoufi ◽  
Theo G. Keith ◽  
Ramin K. Rahmani
Keyword(s):  
Numerical Modeling ◽  
Heat Conduction ◽  
Fluid Mechanics ◽  
Phase Change ◽  
Numerical Method ◽  
Analytical Solutions ◽  
Three Dimensional ◽  
Solution Element ◽  
Explicit Numerical Method ◽  
Element Method

The conservation element and solution element (CE/SE) method, an accurate and efficient explicit numerical method for resolving moving discontinuities in fluid mechanics problems, is used to solve three-dimensional phase-change problems. Several isothermal phase-change cases are studied and comparisons are made to existing analytical solutions. The CE/SE method is found to be accurate, robust, and efficient for the numerical modeling of phase-change problems.

scholarly journals Modeling of the physical phenomenon of heat generation by using partial differential equations

2021 ◽  
Vol 2073 (1) ◽  
pp. 012014
Author(s):  
J J Cadena Morales ◽  
C A López Castro ◽  
H F Rojas Molano
Keyword(s):  
Heat Generation ◽  
Physical Phenomenon ◽  
Separation Of Variables ◽  
Computational Simulation ◽  
Mathematical Physics ◽  
Temperature Function ◽  
Mathematical Arguments ◽  
Solution Methods ◽  
Equations Of Mathematical Physics ◽  
Physical Phenomena

Abstract The equations of mathematical physics are a natural environment for modeling physical phenomena, an example of the above is evidenced by the heat equation in relation to its use in a variety of applications; directly related to the equations of mathematical physics are the solution methods that are used to construct the predictive models. This paper describes step by step the analytical method of separation of variables to perform a complete description of the heat conduction phenomenon in the presence of a heat generation source. The investigation by using mathematical arguments allowed to calculate the temperature function as the addition of a Fourier series and a function which represents the steady state; by performing a computational simulation, it was possible to demonstrate the accuracy of the results achieved.

Mathematical Modeling of Heat Transfer through Clothing System

2011 ◽  
Vol 250-253 ◽  
pp. 3889-3892
Author(s):  
Yu Chai Sun ◽  
Zhong Hao Cheng
Keyword(s):  
Mathematical Modeling ◽  
Heat Transfer ◽  
Heat Conduction ◽  
Theoretical Prediction ◽  
Transfer Process ◽  
Heat Transfer Process ◽  
Conservation Of Energy ◽  
Mathematical Equations ◽  
Boltzmann Law ◽  
Theoretical Results

Based on fundamental principles of Fourier's law of heat conduction, Newton's law of cooling, Stefan-Boltzmann law and the law of conservation of energy, this paper gave out mathematical equations for description of the general heat transfer process through clothing system, and compares the theoretical results with experimental results. The result of the experiment is in accordance with the theoretical prediction.

Application of the Conservation Element and Solution Element Method in Numerical Modeling of Three-Dimensional Heat Conduction With Melting and/or Freezing

2003 ◽  
Author(s):  
Anahita Ayasoufi ◽  
Theo G. Keith
Keyword(s):  
Numerical Modeling ◽  
Heat Conduction ◽  
Fluid Mechanics ◽  
Phase Change ◽  
Numerical Method ◽  
Analytical Solutions ◽  
Three Dimensional ◽  
Solution Element ◽  
Explicit Numerical Method ◽  
Element Method

The conservation element and solution element (CE/SE) method, an accurate and efficient explicit numerical method for resolving moving discontinuities in fluid mechanics problems, is used to solve three-dimensional phase change problems. Several isothermal phase change cases are studied and comparisons are made to existing analytical solutions. The CE/SE method is found to be accurate, robust and efficient for the numerical modeling of phase change problems.

A Study of the Heat Transfer Mechanisms in Horizontal Flame Propagation

1980 ◽  
Vol 102 (2) ◽  
pp. 357-363 ◽  
Author(s):  
S. R. Ray ◽  
A. C. Fernandez-Pello ◽  
I. Glassman
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Conduction ◽  
Flux Distribution ◽  
Heat Transfer Process ◽  
Heat Fluxes ◽  
Temperature Fields ◽  
Gas Velocity ◽  
Field Temperature ◽  
Transfer Mechanisms

An experimental study is performed on the magnitude of the different mechanisms by which heat is transferred from the flaming region to the unburnt fuel ahead of the flame for flames propagating horizontally over the surface of a solid fuel. Measurements of the gas velocity field, temperature fields and radiant flux distribution in a particular case of laboratory scale flame spread over a thick fuel are used to determine the magnitude of the heat fluxes ahead of the flame. The results show that, for this particular case, although heat conduction through the solid is dominant, radiation from the flame contributes significantly to the heat transfer process. An analysis of the development of the fire indicates that there is a transition in the mechanisms of heat transfer as the fire grows. While in the early stages of the fire, heat conduction through the solid is dominant, radiation from the flame becomes of increased importance as the size of the fire increases.

Relationship Between the Nonlocal Effect and Lagging Behavior in Bioheat Transfer

2021 ◽  
Author(s):  
Xiaoya Li ◽  
Yan Li ◽  
Pengfei Luo ◽  
Xiao Geng Tian
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Order Effect ◽  
Heat Transfer Process ◽  
Bioheat Transfer ◽  
Transfer Model ◽  
Phase Lag ◽  
Medical Systems ◽  
Conduction Model ◽  
Transfer Equations

Abstract Lots of generalized heat conduction models have been developed in recent decades, such as local thermal non-equilibrium model, phase lagging model and nonlocal heat conduction model. But no attempt was made to prove which model is better (or worse) than others, or whether there is a certain relationship between these different models. With this inspiration, we establish the nonlocal bioheat transfer equations with lagging time, and the two and three-temperature bioheat transfer equations with considering all the carries' heat conduction effect are also constructed. Comparing the two (or three)-temperature equation model with the nonlocal bioheat transfer models with lagging time, one may obtain: the lagging time tt of temperature gradient and the nonlocal characteristic length ?q in the space derivative items of heat flux have the same effect on heat transfer; when the heat transport occur among N energy carriers with considering the conduction effects of all carries, the heat transfer process are depend on the high-order effect of tqN-1, ttN-1 and ?t(2N-1) in nonlocal dual phase lag bioheat transfer model. This phenomenon is very important for biological and medical systems where numerous carriers may exist on the cellular level.

Heat transfer enhancement via Görtler flow with spatial numerical simulation

2017 ◽  
Vol 27 (1) ◽  
pp. 189-209 ◽  
Author(s):  
Vinicius Malatesta ◽  
Josuel Kruppa Rogenski ◽  
Leandro Franco de Souza
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Boundary Layer ◽  
Numerical Method ◽  
Layer Structure ◽  
Heat Transfer Process ◽  
Content Type ◽  
Transfer Rates ◽  
Görtler Vortices ◽  
Gortler Vortices

Purpose The centrifugal instability mechanism of boundary layers over concave surfaces is responsible for the development of quasi-periodic, counter-rotating vortices aligned in a streamwise direction known as Görtler vortices. By distorting the boundary layer structure in both the spanwise and the wall-normal directions, Görtler vortices may modify heat transfer rates. The purpose of this study is to conduct spatial numerical simulation experiments based on a vorticity–velocity formulation of the incompressible Navier–Stokes system of equations to quantify the role of the transition in the heat transfer process. Design/methodology/approach Experiments are conducted using an in-house, parallel, message-passing code. Compact finite difference approximations and a spectral method are used to approximate spatial derivatives. A fourth-order Runge–Kutta method is adopted for time integration. The Poisson equation is solved using a geometric multigrid method. Findings Results show that the numerical method can capture the physics of transitional flows over concave geometries. They also show that the heat transfer rates in the late stages of the transition may be greater than those for either laminar or turbulent ones. Originality/value The numerical method can be considered as a robust alternative to investigate heat transfer properties in transitional boundary layer flows over concave surfaces.

Numerical Simulation of Arc-Type Slotted Finned Heat Exchanger

2012 ◽  
Vol 248 ◽  
pp. 140-146
Author(s):  
Ping Dao Gu ◽  
Dong Hao Liu ◽  
Jing Lu Yao
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Fluid Mechanics ◽  
Heat Transfer Performance ◽  
Heat Transfer Process ◽  
Simulation Software ◽  
Transfer Performance ◽  
Pitch Height ◽  
Low Velocity ◽  
Large Velocity

This paper is studying the fluid mechanics and heat transfer along the surface of are-type slotted fin in the finned heat exchanger by using the simulation software comsol multiphysics. The major study is the effect of the structure of fin to the fluid mechanics and heat transfer process, including the fin pitch, height of arc-type slit, the size of arc-type slit, the position of arc-type slit. And drawing the following conclusion: under the condition of low velocity, the fin pitch should be around 2.0 mm in considering the overall heat-transfer performance, and under the condition of large velocity, around 1.5 mm is better; When designing the arc-type slotted fin, the more larger the height of arc-type slit do, the better the overall heat-transfer performance; it is better if the start angle, as same as the position of arc-type slit, is less than 30°; the angle of arc-type silt ,as same as the size of arc-type slit, should be larger under the condition of meeting the demand of pressure drop.

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