Autonomous, flexible and controllable generation of finest droplets

该方案的目的是找到一种液滴发生器系统驱动参数的估计方法，以产生比喷嘴直径小得多的液滴。因此，设计了一个自主控制的压电式液滴发生器系统来进行实验，并在精确再现液滴发生器几何形状的基础上对压力分布进行了局部解析模拟，为研究流体腔内的动力学机制提供了服务。其动机是从各种流体中产生不同直径的液滴。自适应控制系统由多个传感器(压电致动器的馈电信号、探测卫星液滴的CCD摄像机、评估稳定性和液滴直径的微型PDA)组成，并自主驱动压电发电机的参数范围以获得单分散的液滴。基于神经模糊方法建立了控制系统的模型，并对其重复性、稳定性和动态性进行了研究。通过高分辨率CFD模拟，结合液滴生成器的材料和几何知识，检验了潜在的流体动力学关系。实验中发现的驱动信号被用作流体动力系统的激励，以研究和分类物理现象，并推导出取决于流体参数的不同液滴直径的产生关系和规律。

The aim of this proposal is to find an estimation method for the driving parameters of a droplet generator system to generate much smaller droplets than the nozzle diameter. Therefore, an autonomously controlled piezoelectrical droplet generator system is designed to perform experiments, and locally resolved simulations of the pressure distribution based on a precise reproduction of the geometry of the droplet generator serve for the investigation of the dynamical mechanisms within the fluid chamber. The motivation is to generate droplets with different diameters from a variety of fluids. This technique can be applied, e.g., in Additive Manufacturing as well as in research.The adaptive control system consists in several sensors (feedbach signal of the piezo actuator, CCD camera to detect satellite droplets, miniature PDA to evaluate stability and droplet diameter) and drives autonomously the parameter range of the piezo generator to get monodisperse droplets. The model of the control system is based on neuro-fuzzy methods and its reproducibility, stability, and dynamic are investigated.The underlying fluid dynamical relations are examined by high resolution CFD simulations with exact knowledge of materials and geometry of the droplet generator. The driving signals found in the experiments are applied as excitations of the fluid dynamical system to investigate and classify the physical phenomenon and to derive relations and rules for the generation of different droplet diameters depending on the parameters of the fluid.