{"id":398594,"date":"2024-12-27T09:13:36","date_gmt":"2024-12-27T09:13:36","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/transient-thermal-result-for-laser-annealing-solidgtgtliquidgtgtsolid\/"},"modified":"2024-12-27T13:30:49","modified_gmt":"2024-12-27T13:30:49","slug":"transient-thermal-result-for-laser-annealing-solidgtgtliquidgtgtsolid","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/transient-thermal-result-for-laser-annealing-solidgtgtliquidgtgtsolid\/","title":{"rendered":"transient thermal result for laser annealing (solid>>liquid>>solid)"},"content":{"rendered":"

<p><p><p><p><p><p>Greeting all:<\/p><p>I would like to know if my settings and assumptions for transient heat transfer are appropriate:<\/p><p>1: For the upper heat convection region, does it need to have directionality?<br>In other modules in Workbench, I’ve seen that the directionality of convection needs to be clearly defined (e.g., FLUENT, ICEPAK, etc.).<br>Currently, I have only set the magnitude of <span class=”katex”><span class=”katex-mathml”>H<\/span><span class=”mord mathnormal”>15<\/span><\/span>, and it is a constant.<br>(My assumption is that air convection only occurs above the model.)<\/p><p>\"\"<\/p><p>2:During the annealing process, the metal undergoes a phase change from solid to liquid due to heating (with a brief two-phase transition in between), and after the laser stops, it cools down slowly (following Newton’s cooling law). The metal transitions back from liquid to solid as it cools.<br>Do I need to define any additional settings for this phase transition between solid and liquid?<br>Currently, I have only set the melting point of the metal (a-Si melting point = 1414°C).\"\"<\/p><p>I noticed that FLUENT has a “melting” feature, and I am unsure if I have chosen the wrong module (using FLUENT instead of Transient Thermal).<\/p><p>If considering the phase change, I made a simple assumption shown in the diagram below:<br>The peak temperature will slightly decrease (the highest point of the red line)  This case mainly focuses on the temperature of the a-Si metal layer on the surface, as it is directly exposed to laser light for annealing.<\/p><p>\"\"<\/p><p> here’s the question, In FLUENT, can the heat flux only be a constant?<\/p><p>Thank you!<br>If you have any suggestions, please let me know.<\/p><\/p><\/p><\/p><\/p><\/p><\/p>\n","protected":false},"template":"","class_list":["post-398594","topic","type-topic","status-publish","hentry","topic-tag-ansys-transient-thermal-2","topic-tag-melting-solidification-2"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t