We introduce a numerical workflow to model and simulate transient close-contact melting processes based on the space-time finite element method. That is, we aim at computing the velocity at which a forced heat source melts through a phase-change material. Existing approaches found in the literature consider a thermo-mechanical equilibrium in the contact melt film, which results in a constant melting velocity of the heat source. This classical approach, however, cannot account for transient effects in which the melting velocity adjusts itself to equilibrium conditions. With our contribution, we derive a model for the transient melting process of a planar heat source. We iteratively cycle between solving for the heat equation in the solid material and updating the melting velocity. The latter is computed based on the heat flux in the vicinity of the heat source. The motion of the heated body is simulated via the moving mesh strategy referred to as the Virtual Region Shear-Slip Mesh Update Method, which avoids remeshing and is particularly efficient in representing unidirectional movement. We show numerical examples to validate our methodology and present two application scenarios, a 2D planar thermal melting probe and a 2D hot-wire cutting machine.
翻译:我们引入了一个数字工作流程,以基于空间-时间限制元素法的模拟和模拟瞬时近距离熔化过程。也就是说,我们的目标是计算强制热源通过相换材料熔化的速度。文献中发现的现有方法考虑接触熔化胶片中的热机械平衡,从而导致热源的不断融化速度。然而,这种经典方法无法说明熔化速度使自身适应均衡条件的瞬时效应。我们的贡献是,我们为一个平板热源的瞬时融化过程制作一个模型。我们反复循环,在固态材料中解决热方与更新熔化速度之间,后者根据热源附近的热通量计算。热体的动动动通过移动网形战略模拟,称为虚拟区域示拉-滑动最新方法,避免重现,特别能代表单向移动。我们展示数字例子,以验证我们的方法,并展示两种应用情景,即2D平面热热热热焦熔化机和2号热压压机。