Effects of Change of Phase on Temperature Distribution Due to a Moving Heat Source

1975 ◽  
Vol 97 (1) ◽  
pp. 39-44
Author(s):  
C. S. Kang ◽  
Y. P. Chang

This paper presents a numerical method for the solution of problems of moving heat sources with change of phase and with any boundary condition. Calculated results of two specific cases are shown: one for a plane moving source in a rod and the other for a line source in a plate. It is found that for low heat input and/or low initial temperature, the change of phase does not affect significantly the temperature distribution in the medium, were it of solid only. However, the higher the heat input and/or the initial temperature, the larger is the effect of phase-change to the temperature field.

2005 ◽  
Vol 297-300 ◽  
pp. 2623-2627
Author(s):  
Xiang Feng Liu ◽  
Lai Gui Wang ◽  
Yong Jiang Yu

When the coal (rock) specimens are tested with infrared, one can observe that the specimens’ temperature field is changing. Commonly, causes of the changes are due to specimens’ plastic deformation and crack extension. But many coherent documents indicate that most specimens even has high temperature field after the peak strength. This paper put a forward that the influence of friction between the fracture planes on the specimens’ temperature field could not be ignored. Meanwhile, the paper gives a simple friction model of two blocks,. In the model, the friction surface plays the different roles to the two blocks as moving heat source and fixed heat source respectively. Those different heat sources have different effect on the blocks’ temperature field. In the end, analytic solutions of temperature change at any point of two blocks that caused by friction are given.


Author(s):  
G Atefi ◽  
M A Abdous ◽  
A Ganjehkaviri ◽  
N Moalemi

The objective of this article is to derive an analytical solution for a two-dimensional temperature field in a hollow cylinder, which is subjected to a periodic boundary condition at the outer surface, while the inner surface is insulated. The material is assumed to be homogeneous and isotropic with time-independent thermal properties. Because of the time-dependent term in the boundary condition, Duhamel's theorem is used to solve the problem for a periodic boundary condition. The periodic boundary condition is decomposed using the Fourier series. This condition is simulated with harmonic oscillation; however, there are some differences with the real situation. To solve this problem, first of all the boundary condition is assumed to be steady. By applying the method of separation of variables, the temperature distribution in a hollow cylinder can be obtained. Then, the boundary condition is assumed to be transient. In both these cases, the solutions are separately calculated. By using Duhamel's theorem, the temperature distribution field in a hollow cylinder is obtained. The final result is plotted with respect to the Biot and Fourier numbers. There is good agreement between the results of the proposed method and those reported by others for this geometry under a simple harmonic boundary condition.


1972 ◽  
Vol 22 (3) ◽  
pp. 381-385 ◽  
Author(s):  
L. A. Brichkin ◽  
Yu. V. Darinskii ◽  
L. M. Pustyl'nikov

2018 ◽  
Vol 210 ◽  
pp. 04036
Author(s):  
Hana Charvátová ◽  
Martin Zálešák

The paper deals with computer testing of the temperature distribution in buildings by using COMSOL Multiphysics software. It is devoted to a description of a computer application created in the Application Builder user interface for simulation of the temperature distribution in a room heated by two heat sources. The application allows you to change geometric dimensions of all elements of the studied model and their spatial distribution, as well as a choice of physical properties needed to access the distribution of temperature in the room depending on the ambient temperature and the heat input of the considered sources. Main functions of the application are presented by simulation of cyclic heating and cooling of the tested room.


2000 ◽  
Vol 123 (2) ◽  
pp. 185-190 ◽  
Author(s):  
T. Jin ◽  
G. Q. Cai

Three related analytical thermal models of plane heat source moving obliquely along the surface of a semi-infinite solid are presented. The temperature distribution of grinding zone under deep-cut conditions is investigated with these models. It is proposed that the oblique angle of the heat source plane to its moving direction has an essential influence on the grinding zone temperature rise and its distribution of high efficiency deep grinding (HEDG). Compared with that in creep-feed grinding, HEDG has a different form of heat flux distribution in grinding zone and should be treated with different thermal models. The temperature distribution at the shear zone of orthogonal cutting is also briefly discussed with the thermal models. The models developed in the paper provide a more rational and integrated analytical basis for dealing with the heat transfer problems of inclined moving heat sources.


1991 ◽  
Vol 113 (2) ◽  
pp. 215-221 ◽  
Author(s):  
Elijah Kannatey-Asibu

The high cooling rates normally encountered in the application of high intensity welding processes such as laser beam welding is often detrimental to the weldment, especially for high hardenability steels. To minimize this effect, the split-beam laser welding concept is proposed and analyzed. The analysis shows that even when the intensity of the single heat source is the same as the intensity of each of the dual heat sources, the resulting cooling rate at any specific temperature is lower for the dual source process than the single source process. For example, for mild steel, the cooling rate at a point 25 mm behind the heat source (where the temperature is 1364°C) was determined to be 382°C/s for the single source system, while that for a point 40 mm behind the major source (where the temperature is 1377°C) was determined to be 206°C/s for the dual heat source system. When the heat inputs for the dual system are reduced such that the total heat input is equal to that of the single source system, the resulting temperature rise is lower at all points of the weldment for the dual system. That also means a smaller weld pool size and heat affected zone. To maintain the same weld pool size and penetration as for the single heat source system then requires an increased total heat input for the dual heat source system, with the additional input depending on the spacing between the two heat sources.


2009 ◽  
Vol 626-627 ◽  
pp. 105-110 ◽  
Author(s):  
Guo He Li ◽  
Min Jie Wang

A method was presented for calculating the temperature distribution of primary shear zone in orthogonal high speed cutting based on the non-uniform volume moving heat source. The temperature distribution of primary shear zone in orthogonal high speed cutting was calculated by the dynamic plastic constitutive relationship and the distribution of strain and strain rate of primary shear zone. The results show that the temperature distribution of primary shear zone is uneven, from the original plane to the cutoff plane, the cutting temperature increases continuously. In the middle of primary shear zone, the change of cutting temperature is larger, at the position near to original plant and cutoff plane, the change of cutting temperature is smaller. The cutting temperature increases with the increase of cutting speed and cutting depth, but decreases with the increase of rake angle. The comparison with existing method shows that the method presented in this paper is not only available, but also simple, convenient and more accord with the fact of orthogonal high speed cutting.


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