scholarly journals Effect of two dimensional heat conduction within the wall on heat transfer of a tube partially heated on its circumference.

1987 ◽  
Vol 53 (494) ◽  
pp. 3076-3081
Author(s):  
Isao SATOH ◽  
Yasuo KUROSAKI
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Two Dimensional

Influence of Brazing on the Heat Transfer Performance of Fins in Radiators

2000 ◽  
Author(s):  
Bengt Sundén ◽  
Andreas Abdon ◽  
Daniel Eriksson
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Detrimental Effect ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Two Dimensional ◽  
Air Gaps ◽  
One Dimensional ◽  
Temperature Distributions ◽  
Braze Joint

Abstract The performance of a radiator copper fin is considered as the braze joint between the fin and the brass tube is not perfect. The influence of different thermophysical properties of the brazing materials, created intermetallic compounds and possible air gaps is considered. Numerical methods for both two-dimensional and one-dimensional calculations have been developed. The finite volume technique is applied and in the two-dimensional case, boundary fitted coordinates are used. Heat conduction in the fin and braze joint coupled with convective heat transfer in a gas stream is analysed. Results in terms of fin temperature distributions and fin efficiencies are provided. It is found that the detrimental effect of a poor braze joint is not as large as reported previously in the literature.

scholarly journals A Review of Peridynamics (PD) Theory of Diffusion Based Problems

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Migbar Assefa Zeleke ◽  
Mesfin Belayneh Ageze
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Two Dimensional ◽  
Numerical Examples ◽  
Transfer Processes ◽  
Recent Developments ◽  
Nonlocal Nature

The study of heat conduction phenomena using peridynamic (PD) theory has a paramount significance on the development of computational heat transfer. This is because PD theory has got an interesting feature to deal with the inherent nonlocal nature of heat transfer processes. Since the revolutionary work on PD theory by Silling (2000), extensive investigations have been devoted to PD theory. This paper provides a survey on the recent developments of PD theory mainly focusing on diffusion based peridynamic (PD) formulation. Both the bond-based and state-based PD formulations are revisited, and numerical examples of two-dimensional problems are presented.

Heat transfer at small Grashof numbers

1957 ◽  
Vol 238 (1214) ◽  
pp. 412-423 ◽  
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Ambient Temperature ◽  
Heat Conduction Equation ◽  
Body Shape ◽  
The Body ◽  
Conduction Equation ◽  
Two Dimensional ◽  
Transfer Rates ◽  
Theory And Experiment

Rough physical arguments suggest that the heat transfer from a body, immersed in a fluid, should be determined by the heat-conduction equation alone whenever the Grashof number, G , associated with the problem is small. However, heat-transfer rates predicted in this fashion are not always in accordance with the experimentally determined values. It is shown that, while convection is negligible in comparison with conduction near the body, it becomes as important at distances from the body of the order ( G ) -n , where n varies between 1/3 and ½ with the body shape. Whenever this distance is large in comparison with all the dimensions of the body the use of the conduction equation yields correct heat-transfer rates. If, however, this distance is small in comparison with the body length, the heat transfer may be calculated from the two-dimensional convection solution. An examination of the solutions in these two extreme cases reveals that the heat loss is the same as that by conduction to a certain surrounding surface maintained at ambient temperature. This interpretation enables certain qualitative deductions to be made for the case when the ratio of the lengths is neither large nor small. The agreement between theory and experiment is satisfactory.

Study of the effects of wall conductance on natural convection in differently oriented square cavities

1984 ◽  
Vol 144 ◽  
pp. 153-176 ◽  
Author(s):  
D. M. Kim ◽  
R. Viskanta
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Natural Convection ◽  
Convection Flow ◽  
Two Dimensional ◽  
Coupled Flow ◽  
Square Enclosure ◽  
Flow And Heat Transfer ◽  
Boussinesq Fluid ◽  
Solid Walls

This paper reports experimental and numerical results on the effects of wall conductance on natural convection in a two-dimensional rectangular cavity. Three different configurations in which the external wall is heated from the side, top and bottom and cooled from the side, bottom and top respectively have been investigated. Experiments have been performed in a square enclosure with solid walls made from Lexan and forming a square air-filled cavity. A Mach–Zehnder interferometer was used to determine the temperature distributions in the fluid. Solutions for stationary two-dimensional equations of energy and motion governing heat conduction in the solid and natural convection flow and heat transfer of a Boussinesq fluid contained in the cavity have been obtained numerically. The coupled flow distributions, including the appearance of multicellular flow, temperature profiles and heat-transfer predictions compare favourably with experimental results. Heat conduction in the connecting (unheated) walls is shown to simultaneously stabilize and destabilize the fluid in the cavity.

scholarly journals Exterior Shape Factors From Interior Shape Factors

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
John H. Lienhard
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Conformal Mapping ◽  
Analytical Determination ◽  
Two Dimensional ◽  
Shape Factors ◽  
Transfer Rates ◽  
Steady Heat Conduction ◽  
Steady Heat

Shape factors for steady heat conduction enable quick and highly simplified calculations of heat transfer rates within bodies having a combination of isothermal and adiabatic boundary conditions. Many shape factors have been tabulated, and most undergraduate heat transfer books cover their derivation and use. However, the analytical determination of shape factors for any but the simplest configurations can quickly come to involve complicated mathematics, and, for that reason, it is desirable to extend the available results as far as possible. In this paper, we show that known shape factors for the interior of two-dimensional objects are identical to the corresponding shape factors for the exterior of those objects. The canonical case of the interior and exterior of a disk is examined first. Then, conformal mapping is used to relate known configurations for squares and rectangles to the solutions for the disk. Both a geometrical and a mathematical argument are introduced to show that shape factors are invariant under conformal mapping. Finally, the general case is demonstrated using Green's functions. In addition, the “Yin-Yang” phenomenon for conduction shape factors is explained as a rotation of the unit disk prior to conformal mapping.

Sign in / Sign up

Export Citation Format

Share Document