Active Control of Liquid Jet Breakup for Advanced Manufacturing

先进制造中液体射流破碎的主动控制

• 批准号: 0727609
• 负责人: Derek Dunn-Rankin
• 金额: $ 20万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0727609&HistoricalAwards=false
• 关键词: Active; Control; Liquid; Jet; Breakup

Liquid sprays and aerosols play an important role in a myriad of manufacturing environments, from food and chemical processing to netshape manufacturing and pharmaceuticals. For each application, the ideal size of the droplets in the spray and their desired momentum varies. Currently, however, liquid droplets are generated during a vigorous and chaotic breakup event from a bulk fluid, making prediction and control of droplets difficult. Improved real-time control of droplet size and trajectory could therefore have significant impacts on advanced manufacturing and processing methods. This project?s goal is to demonstrate a novel approach for generating, manipulating, and controlling droplets. The concept is to develop a control methodology for adjusting the breakup of a simple capillary jet into droplets with predictable and variable size and momentum. While the mechanism for capillary jet breakup is not identical in all complex sprays, it can serve as a model for the development of control strategies for other droplet and spray applications as well.The breakup of liquid jets into uniform droplets in response to ideal perturbations on the jet has been studied for many years. In practical systems, however, actuator dynamics make it difficult to create a pure excitation, thereby limiting the breakup performance to a small range of droplet sizes. In the proposed work, we explore the possibility of expanding the breakup performance window by controlling the input waveforms to the perturbation source in order to suppress disruptive components. The study begins by identifying the response dynamics of a typical piezoelectric actuator to a pure sinusoidal input. An inverse problem solution then produces the non-sinusoidal input wave needed to suppress undesirable response modes and ensure that the actuator perturbs the jet with only one dominant frequency. Experimental verification of this open-loop control performance on a liquid jet follows. The project then develops a real-time identification approach to allow corrections and adjustments to the input waveform in response to the desired output droplet behavior. Hence, the project has two elements: (1) a control component that uses the dynamic features of the perturbed capillary jet to develop a system model to which control techniques can be applied and (2) an experimental component that develops a capillary jet breakup system and control apparatus that can be stimulated and controlled via sensor and actuator feedback loops in order to verify the control findings.

液体喷雾剂和气雾剂在从食品和化学加工到净形状制造和制药的众多制造环境中发挥着重要作用。 对于每种应用，喷雾中液滴的理想尺寸及其所需的动量各不相同。 然而，目前，液滴是在大量流体剧烈且混乱的分裂过程中产生的，这使得液滴的预测和控制变得困难。 因此，改进液滴尺寸和轨迹的实时控制可能对先进的制造和加工方法产生重大影响。 该项目的目标是展示一种生成、操纵和控制液滴的新方法。 这个概念是开发一种控制方法，用于将简单的毛细管射流调整为具有可预测且可变的尺寸和动量的液滴。 虽然毛细管射流破碎机制在所有复杂喷雾中并不相同，但它也可以作为开发其他液滴和喷雾应用的控制策略的模型。响应于射流上的理想扰动将液体射流破碎成均匀的液滴已经研究了很多年。 然而，在实际系统中，执行器动力学使得很难产生纯粹的激励，从而将破碎性能限制在小范围的液滴尺寸内。 在拟议的工作中，我们探索了通过控制扰动源的输入波形来扩展破碎性能窗口的可能性，以抑制破坏性成分。 该研究首先确定典型压电执行器对纯正弦输入的响应动力学。 然后，逆问题解决方案会产生抑制不良响应模式所需的非正弦输入波，并确保致动器仅以一个主频率扰动射流。 下面对液体射流的开环控制性能进行实验验证。 然后，该项目开发了一种实时识别方法，可以根据所需的输出液滴行为来校正和调整输入波形。 因此，该项目有两个要素：(1) 控制组件，利用扰动毛细管射流的动态特征来开发可以应用控制技术的系统模型；(2) 实验组件，开发毛细管射流破碎系统和控制装置，可以通过传感器和执行器反馈回路进行激励和控制，以验证控制结果。