Experimental and numerical investigation of the flow process of high-pressure water jets and their interaction with technical component surfaces

在机械工程领域，液体冲蚀在技术部件的表面材料去除中起着重要作用。虽然这种现象在制造技术中特别用于零件的加工，但它经常在许多技术应用中作为不期望的影响发生，导致部件损坏甚至故障。为了科学地分析这种液体侵蚀现象，以优化生产工艺中的材料去除过程，减少其他工艺系统中的不必要侵蚀，需要进行大量耗时且昂贵的试验。在这种情况下，高压水射流的一个特殊作用是在制造过程中经常用于加工零件。高压水射流用于在对该现象敏感的部件的开发中实现限定水平的液体侵蚀。在本研究计划的范围内，将研究高压水射流的流动过程，包括射流喷嘴中的流动行为、射流的破碎和液滴在受影响部件表面上的撞击。将使用激光测量和高速摄影以及压电和压阻测量方法来分析破碎和与固体材料的相互作用。在此基础上，提出了用有限体积法和欧拉-欧拉法对整个流动过程进行数值模拟的方法。最后的目标是支持和改进虚拟产品开发过程中的三重方式：通过最大限度地减少不良侵蚀的组件在产品开发过程的早期阶段，通过优化的表面处理，从生产技术的角度来看，最后通过减少所需的实验来分析这一现象的数量。

In the field of mechanical engineering, liquid erosion plays an important role in the surface material removal of technical components. Although this phenomenon is used in manufacturing technology specifically for the machining of parts, it often occurs as an undesirable influence in many technical applications, causing damage or even failure of components. In order to analyze this phenomenon of liquid erosion scientifically, with the aim to both optimize the process of material removal in pro-duction technology and reduce unwanted erosion in other technical systems, numerous time-consuming and expensive tests are required. A specific role in this case play high-pressure water jets which are often used for machining parts in manufacturing processes. High pressure water jets are used to realize a defined level of liquid erosion in the development of components that are sensitive to that phenomenon. With the scope of this proposed research project, the flow process of high-pressure water jets will be examined, including the flow behavior in the jet nozzle, the breakup of the jet and the droplet impingement on the affected component surface. The breakup and the interaction with the solid material will be analyzed in using laser measurements and high speed photography as well as piezoelectric and piezoresistive measurement methods. Based on the results, a method shall be developed using which, the entire flow process can be numerically simulated with the Finite Volume Method and the Euler-Euler Method. The final aim is to support and improve the process of virtual product development in a threefold manner: by minimizing the undesirable erosion of components in the early stages of product development process, by opti-mizing the surface processing from the point of view of production technology and finally by reduc-ing the number of experiments required to analyze this phenomenon.