Multiphase modelling of cutting fluid and its aerosols in cutting simulations using the Finite Pointset Method (FPM) for analysing the mechanisms of action (MultiCuttingFluid)

切削液及其气雾剂的作用机理目前还不完全清楚。对于不同的因素，如工艺参数、切削液策略或切削液的性质，这些作用机理有不同的未经证实的理论。例如，由于切屑和刀具表面温度较高而形成的绝缘蒸汽层的冲刷，被认为是高于一定切削液压力的冷却效果增加的原因。雾化切削液的积极作用部分归因于液滴蒸发，这种雾化切削液用于最小润滑(MQL)加工。即使是液滴在喷雾中的传输、液滴-液滴碰撞、液滴热壁碰撞和液滴蒸发等基本过程，也会受到切削液性质的影响，从而改变作用机制，这些科学问题将通过无网格有限点集方法(FPM)在本研究项目中得到数值解答。这种方法的优点是能够完全模拟刚性和可变形的结构和流体，以及在大变形过程中的流体-结构-相互作用。因此，目前有可能通过考虑单相流体来模拟湿法圆柱车削过程的切屑形成。在本研究项目中，现有的模型通过汽相和喷雾以及它们的物理作用机制进行了扩展。汽相是通过使用扩展的状态方程在FPM中作为整体数值实体来实现的。喷雾内的基本过程由拉格朗日方法实现的液滴相互作用的半经验模型来考虑。模型的开发将基于详细的实验室实验。所得到的切削液及其气溶胶的多相模型用于对加工过程中的作用机理进行数值研究。为了实现这一目标，在项目期1内开发了与蒸发有关的切削液及其作用机理的模型。在接下来的项目期2中，这些模型被集成到切削模拟中以分析切削过程中的蒸发机理。此外，为了在项目阶段3应用MQL，对切削液的模型进行了喷雾阶段的扩展。这些发展是为了增加对考虑切削液的切削的一般理解，以及对洪水冷却、高压冷却和MQL冷却策略进行生态和经济优化。

The mechanisms of action of cutting fluids and its aerosols are not fully understood today. There are different unproved theories for these mechanisms of action for various factors like process parameters, cutting fluid strategy or properties of cutting fluids. For example, the flush out of an insulating vapour layer which is formed due to high chip and tool surface temperatures, is assumed to be the cause of an increased cooling effect above a certain cutting fluid pressure. The positive influence of atomized cutting fluids in the form of sprays, which is used for minimum quantity lubrication (MQL) machining, is partly attributed to the drop evaporation. Even the elementary processes, such as drop transport, drop-drop collisions, drop hot wall collisions and drop evaporation within a spray, are influenced by the cutting fluid properties which change the mechanisms of action.These scientific issues will be numerically answered by using the meshfree Finite Pointset-Method (FPM) during this research project. The advantage of the FPM is the ability for completely modelling rigid and deformable structures and fluid, as well as fluid-structure-interactions during large deformations using this method. Therefore, it is currently possible to simulate chip forming for a wet cylindrical turning process by considering a single-phase fluid. During this research project the existing models are extended by vapour phase and spray as well as their physical mechanisms of action. The vapour phase is implemented in the FPM as a monolithic numerical entity by using an extended equation of state. Elementary processes within a spray are considered by semi-empirical models of droplet interactions implemented in a Lagrange way. The model development will be based on detailed laboratory experiments. The resulting multiphase model of the cutting fluid and its aerosols is used to numerically investigate the mechanisms of action in the machining process.In order to achieve this aim, models of the cutting fluid and its mechanisms of action are developed with regard to evaporation within project period 1. In the following project period 2 these models are integrated into cutting simulations to analyse evaporation mechanisms during cutting. Furthermore, the models of the cutting fluid are extended by a spray phase for the purpose of MQL applications in project period 3. The developments are used to increase the general understanding of cutting considering a cutting fluid as well as for ecological and economical optimisations of the cooling strategies flood cooling, high pressure cooling and MQL.