Two Dimensional Transient Analysis of Temperature Distribution in a Solid Irradiated by a Gaussian Laser Source

Volume 1 ◽  
2004 ◽  
Author(s):  
Nicola Bianco ◽  
Oronzio Manca ◽  
Sergio Nardini

The use of localized heat source, such as lasers and electron beams, in many manufacturing processes has received a lot of attention in last years. This is due to their versatility and to the possibility to concentrate high powers over small areas. In this paper the transient two dimensional thermal field in a solid irradiated by a moving Gaussian laser beam has been numerically analyzed. The numerical simulation allows for both surface heat losses, convective and radiative, and variable thermophysical properties. Three cases are considered: one is related to an adiabatic workpiece, the other two to a diabatic workpiece with a constant or variable heat transfer coefficient on the upper and lower surfaces. Results show that a local quasi-steady state condition is reached after a time that is much larger when the solid is adiabatic than the cases with constant or variable heat transfer coefficient. Thermal gradients along the depth decrease as z and x coordinates increase.

2021 ◽  
pp. 1-19
Author(s):  
Muhammad Ahmad Jamil ◽  
Talha S. Goraya ◽  
Haseeb Yaqoob ◽  
Muhammad Wakil Shahzad ◽  
Syed M. Zubair

Author(s):  
Alain J. Kassab ◽  
Eduardo A. Divo ◽  
Minking K. Chyu ◽  
Frank J. Cunha

The purpose of the inverse problem considered in this study is to resolve heat transfer coefficient distributions by solving a steady-state inverse problem. Temperature measurements at interior locations supply the additional information that renders the inverse problem solvable. A regularized quadratic functional is defined to measure the deviation of computed temperatures from the values under current estimates of the heat transfer coefficient distribution at the surface exposed to convective heat transfer. The inverse problem is solved by minimizing this functional using a parallelized genetic algorithm (PGA) as the minimization algorithm and a two-dimensional multi-region boundary element method (BEM) heat conduction code as the field variable solver. Results are presented for a regular rectangular geometry and an irregular geometry representative of a blade trailing edge and demonstrate the success of the approach in retrieving accurate heat transfer coefficient distributions.


1974 ◽  
Vol 96 (4) ◽  
pp. 459-462 ◽  
Author(s):  
Terukazu Ota ◽  
Nobuhiko Kon

Heat transfer measurements are made in the separated, reattached, and redeveloped regions of the two-dimensional air flow on a flat plate with blunt leading edge. The flow reattachment occurs at about four plate thicknesses downstream from the leading edge and the heat transfer coefficient becomes maximum at that point and this is independent of the Reynolds number which ranged from 2720 to 17900 in this investigation. The heat transfer coefficient is found to increase sharply near the leading edge. The development of flow is shown through the measurements of the velocity and temperature in the separated, reattached, and redeveloped regions.


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