Computer Simulation of Heat Flow Induced by Laser Irradiation in Presence of Heat Sinks or Sources

1992 ◽  
Vol 279 ◽  
Author(s):  
Sebastiano Tosto

ABSTRACTThe paper concerns the computer simulation of heat flow induced on matter by laser irradiation in presence of heat sources or sinks. The model is 3D analytical and accounts for the dependence of thermal properties of matter on temperature. The results describe in particular the effect of a heat source due to a local phase change or solid state reaction releasing energy in a point of the laser affected zone. The purpose of the paper is to evidence how this additional energy affects the thermal field and then the heating and cooling rates. PACS 47.25.-Qv

1984 ◽  
Vol 35 ◽  
Author(s):  
C.K. Ong ◽  
H.S. Tan ◽  
E.H. Sin

ABSTRACTThe heat flow calculations have been performed to obtain the threshold energies for the melting of Si and Al during pulsed-laser irradiations under various laser conditions. The temperature dependent optical and thermal properties of the solids are deduced from the available experimental data. The melting threshold energies calculated for the solids are within the accuracy of the experimental values.


Author(s):  
Kang-Yul Bae ◽  
Young-Soo Yang ◽  
Myung-Su Yi ◽  
Chang-Woo Park

To manufacture a steel structure, in the first step, raw steel plate needs to be cut into proper sizes. Oxy-fuel flame is widely used in the cutting process due to its flexibility with respect to accessibility, plate thickness, cost, and material handling. However, the deformation caused by the cutting process frequently becomes a severe problem for the next process in the production of steel product. To decrease the deformation, the thermo-elasto-plastic behavior of the steel plate in the cutting process should be analyzed in advance. In this study, heat sources in oxy-ethylene flame cutting of steel plate were modeled first, and the heat flow in the steel plate was then analyzed by the models of the heat sources using a numerical simulation based on the finite element method. To verify the analysis by the numerical simulation including the models, a series of experiments were performed, and the temperature histories at several points on the steel plate during the cutting process were measured. Moreover, the predicted sizes of the heat-affected zone by the numerical simulations according to the variation in the cutting parameters were compared to the experimental results. The power functions of the relationship between the sizes of the heat-affected zone and cutting parameters were obtained by the recursion analysis using the correlation between the results and parameters. The results of the numerical simulation showed good agreement with those of the experiments, indicating that the proposed models of the heat sources and thermal analysis were feasible to analyze the heat flow in the steel plate during the cutting process.


1960 ◽  
Vol 82 (3) ◽  
pp. 155-169
Author(s):  
Thomas F. Irvine ◽  
R. W. Graham ◽  
G. Morrell ◽  
R. D. Turnacliff ◽  
J. H. Robinson ◽  
...  

The survey has been divided into the following parts: Rocket-Engine Heat Sources; Rocket Cooling Techniques; Nozzle Wall Materials; Variable Fluid-Property Effects; Predictions of Thermal Properties; Flow Separation and Acoustic Effects.


2008 ◽  
Vol 33-37 ◽  
pp. 1307-1312
Author(s):  
Mutellip Ahmat ◽  
Wei Cheng ◽  
Li Zheng

In this study, the chief heat sources of the spindle system for the TH6350 Machining Center are analyzed, and an experimental system based on the virtual instruments technology is presented, thirty-two thermocouple sensors are set at the spindle system of the machining center to measure the thermal field, and five electric vortex sensors are used to measure the thermal error of the spindle by five-point method. The FEM modeling of the thermal deformation of the spindle system is built up by based of I-DEAS, the temperature field and the thermal deformation of it are calculated, and the calculated values of the model tallies with the experimental values.The researching results provide a theoretical foundation for the improving design􀋈temperature controlling and the error compensation to the machining center.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Vladimir Leonov

Thermal properties of humans were studied in the case where a small-size energy scavenger is placed on the body. In such a case, the human being serves as a heat source for the thermopile of the scavenger, but the latter serves as a thermally insulating object. As a result, the body properties, namely, the skin temperature, heat flow, and thermal resistance locally change. This is the result of redirection of heat flow inside the body to colder zones because of thermal insulation provided by the scavenger. Increased thermal resistance of human body, in turn, affects the design of the scavenger. The analysis of such scavenger performed for ambient temperatures of 0°C to 25°C shows that it could reach competitive performance characteristics and replace batteries in low-power wearable electronics. A simulated power of up to 60 μW/cm2 at 0°C has been validated by using wearable thermoelectric modules.


2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1877-1884 ◽  
Author(s):  
Diego Alarcón ◽  
Eduardo. Balvís ◽  
Ricardo Bendaña ◽  
Alberto Conejero ◽  
de Fernández ◽  
...  

We present a detailed study of heating and cooling processes in LED luminaires with passive heat sinks. Our analysis is supported by numerical simulations as well as experimental measurements, carried on commercial systems used for outdoor lighting. We have focused our analysis on the common case of a single LED source in thermal contact with an aluminum passive heat sink, obtaining an excellent agreement with experimental measurements and the numerical simulations performed. Our results can be easily expanded, without loss of generality, to similar systems.


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