Articles techniques et présentations

基于 Level-Set 界面跟踪方法建立了激光熔覆过程的三维瞬态数值模型，研究了瞬态熔化和凝固过程中传热传质的演化规律。该模型使用 Level-Set 方法跟踪熔池气/液界面，采用焓－多孔度（enthalpy-porosity）方法得到了固/液界面之间的糊状区，并考虑了质量添加、材料熔化/凝固、热毛细效应（Marangoni效应）、浮力效应、活性元素质量传输等对熔池流动和界面的影响。通过该模型，具体分析了质量添加、力和界面平衡条件对熔池气/液界面的影响，以及由熔池温度/浓度分布引起的热毛细效应、金属材料的熔/凝过程和熔池流动形式对熔池固/液界面的影响。结果表明 ... En savoir plus

Some types of mechanical devices, such as molds, but not only, include a large number of micro-mechanisms, valves, channels, vents, or other devices subject to deterioration or malfunctioning, frequently caused by unwelcome phenomena such as incrustations, fillings, or reciprocal bonding ... En savoir plus

This paper presents a methodology towards designing, analyzing and optimizing piezoelectric interdigitated microactuators using COMSOL Multiphysics. The models used in this study were based on a circularly interdigitated design that takes advantage of primarily the d{;sub}33 ... En savoir plus

Gas-liquid falling film microreactors carry out fast exothermic and mass transfer limited reactions. Since the major rate limiting steps occur on the liquid side, it is important to account for a realistic liquid film profile within the reactor simulation. Based on realistic channel ... En savoir plus

Metamaterials are a new class of artificial materials, which possess various unusual properties. One of these properties is a negative index of refraction produced by setting both the dielectric permittivity ε and the magnetic permeability μ of the material less than zero. Unique ... En savoir plus

Soft tissues are longest tissue structures found throughout a human body. It plays a vital role in connecting, providing support or surround other structures and organs of the body. Muscles, skin, tendons, ligaments, nerves, fibrous tissues, fat, blood vessels are commonly classified as ... En savoir plus

Thermal ablation is a treatment option in oncology that can be used to target primary and metastatic cancers. In this approach, high temperature heating is administered at the target tumor site to induce coagulative necrosis of malignant cells. One minimally invasive method for ... En savoir plus

Investment casting is practised in both the automotive and aerospace industries, to produce casted components where a high-quality surface finish is critical. Vacuum induction melting (VIM) and direct pouring into an investment casting shell mould is an advantageous manufacturing ... En savoir plus

由于异种金属的热物理性能存在较大差异，在焊接过程中极易形成金属间化合物，这给两种材料的焊接造成了一定的困难。因此，针对钢/铝异种金属焊接存在的难点，建立了基于COMSOL软件的激光-TIG复合热源焊三维瞬态熔池数值分析模型。利用所建模型对不同焊接条件下的激光-TIG复合热源焊熔池形貌和温度场进行模拟计算，分别探讨了激光功率、电弧电流及焊接速度对复合焊焊接温度场的影响规律。 En savoir plus

Marangoni flow affects the heat and mass transfer occurring in the molten metal regions in welding and additive manufacturing processes. It originates from the surface tension gradient (∂γ/∂T) induced at the melt pool surface due to the temperature difference. The flow pattern within ... En savoir plus