Autonomous, flexible and controllable generation of finest droplets

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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.