【作者】 吴丽萍；

【导师】 杨志刚； 程光明；

【作者基本信息】 吉林大学 ， 机械设计及理论， 2008， 博士

【摘要】 压电泵是近年发展起来的一种新型流体输送装置,由于具有流量精度高、控制性好、结构简单、体积小、成本低等优点,在医疗制药、生物工程、化学分析、仪器仪表等领域具有广阔的应用前景。现有压电泵主要有无阀型与有阀型两大类,其中无阀型压电泵依靠置于进出口的收缩管与扩张管的阻力差实现流体的单向流动。本文提出在压电泵内部设置扁锥形孔腔,通过压电振子与扁锥形孔腔对流体的共同作用实现流体的单向流动,是一种新型无阀压电泵(以下简称扁锥腔无阀压电泵)。本文阐述、分析了这种压电泵的工作原理、结构与基本理论问题,制造样机进行了试验。主要研究内容如下:首先分析了扁锥腔无阀压电泵的主要驱动元件-圆形复合压电振子的动力学状态,以多种支撑方式为边界条件,分析、推导了压电振子弹性曲面微分方程和振动方程,获得了结构与尺寸参数对压电振子性能的影响规律;而后通过实验测试了压电振子的变形状态,为合理设计压电泵结构与尺寸取得依据。基于扩张管/收缩管流体力学理论阐述了扁锥腔无阀压电泵结构构成方法与工作原理,分析了在压电振子与扁锥腔共同作用下流体的流动阻尼与受力状况,推导出了流量计算公式,解释了自吸性的成因与影响因素;在此基础上进一步利用Fluent分析软件对扁锥腔无阀压电泵的工作过程进行了模拟仿真分析,获得了扁锥腔锥角、腔高等结构参数对扁锥腔无阀压电泵输出性能的影响规律。设计、制作了多个锥角、腔高等结构参数的扁锥腔无阀压电泵样机,分别以纯净水、不同粘度的甘油水溶液为传送介质,测试了多个驱动电压与工作频率状态下的输出性能;试验数据与理论分析结果取得了较好的一致性。由此可以认为利用扁锥形孔腔构造无阀压电泵是可行的,它是无阀压电泵的一种新型构造方法。扁锥腔无阀压电泵为本文首先提出并进行了相关研究,目前国内外均未见有相同原理压电泵的研究报道,具有创新性。本文由国家高技术研究发展计划项目(863计划)《具有自检测功能的微型压电泵开发研究》(项目编号:2007AA04Z336)和国家自然基金项目《主动阀压电泵作用机理及关键技术研究》(项目编号:50575093)提供资助,是这两个项目研究内容的一部分。更多还原

【Abstract】 Piezoelectric Pump is a new type of fluid conveying device that developed in recent years. Its advantages include: high output volume accuracy, easy to control, simple structure, small size and low cost, etc. These advantages make it suitable to be applied in medical treatment, biotechnology, chemistry and instrument development, etc. Usually, piezoelectric pumps can be categorized into two types—valveless and valve based. Valveless piezoelectric pump is based on the expansion / contraction theory that show a resistant difference between input and output ports drives fluid flowing in one direction.This research is part of "863" National High Technology Research and Development project "Study of Micro-Piezoelectric Pump with Self-Detect Functions" (Project Number: 2007AA04Z336) and National Science Foundation project "Principle and Key Technology Study on Initiative Valve Piezoelectric Pump" (Project Number: 50575093) . This dissertation brings forward a novel Flat-Cone-Shape Chamber Valveless Piezoelectric Pump (FCSCVPP) that can convey fluid flowing in one direction by the coaction of piezoelectric actuator and chamber shape. In the dissertation, FCSCVPP’s working principle, structure and other related theories will be introduced and analyzed. Based on pump prototype, a series experiments are applied to prove theoretical and simulation analysis. This dissertation includes following chapters:1、History, Recent Development and Application of Piezoelectric PumpAccording to the research of current Piezoelectric Pump developments in the world, valveless piezoelectric pump is one of the hot-points in this field. In this paper, the FCSCVPP piezoelectric pump structure that is based on the expansion / contraction theory is brought forward.2、Piezoelectric Actuator Working Principle and Characteristics AnalysisCircle piezoelectric actuator—the heart part of FCSCVPP is studied. First, actuator’s dynamics state is analyzed, and then, the curved face differential equation and vibration equation of actuator are derived and analyzed based on multi-support conditions. Based on theoretical conclusion, according experimental tests are applied on the actuator. Experimental results and theoretical analysis both prove that structure, size dimension, support method and material characteristics are the main factors that affect actuator vibration. When rectangular stimulate voltage is applied on the actuator, actuator has biggest vibration, and the vibration is directly related to the voltage volume.3、FCSCVPP Structural Design and StudyFirst, based on the research of the Piezoelectric Pumps that developed in the world, and the expansion / contraction tube fluid flowing theory, FCSCVPP’s structural design and working principle are analyzed. Then, based on the coaction of actuator vibration and flat-cone-shape chamber, fluid resistance and force situation are derived. Next, the fluid volume and resistance relationship equation is worked out on both input and output processes. According to this equation, the net input volume in the input process and the net output volume in the output process are also calculated. Theory analysis show that there are both laminar and eddy flow existing in pump chamber. Theory analysis also shows that pump has better performance when bigger cone side as the output side and small cone angle can generate bigger output volume. Finally, pump self-suction ability is analyzed, the reason and affect factors are explained.4、FCSCVPP Chamber Flow Simulation and Analysis Using "Fluent"FCSCVPP’s chamber flow three dimension model is created by "GAMBIT" before it is input into "Fluent" software, then, simulation results are obtained for different pump design parameters. According to simulation results, the relationship between FCSCVPP’s output performance and chamber angel, chamber height and other parameters are obtained. Results show that: when the input speed is slow and pressure is low, the water flows faster from small side of flat cone chamber than from the big side of flat cone chamber; the bigger is the flat cone angle, the more is spire number and the bigger is spire area; on the opposite, the smaller is the flat cone angle, the less is spire number and the smaller is spire area, till last, the water flows linearly through; when the chamber, input port and output port fluid speed is in high situation, the higher is the flat cone chamber, the easier is spire area generated and the bigger is energy loss, thus, the worse is the output performance. This simulation result agrees with the speed / volume analysis of expansion / contraction dynamic theory, it also agrees with the prototype experimental results.5、FCSCVPP Prototype and ExperimentsFCSCVPP prototypes with different flat cone angles and chamber heights are designed and assembled. In order to reduce the assembly and stimulation errors between these prototypes, all the prototypes and built in one unit, and stimulated by the same voltage and frequency signal. In this section, FCSCVPP prototype experimental materials and equipments are introduced and experimental process and structural parameters are detailed. In these experiments, pure water is used as the pump fluid, and different stimulation voltage and frequency are tested:(1) For the same FCSCVPP, different frequency stimulate signals have different output characteristics. At low frequency range, flat cone small side has better output than the big side; at high frequency range, opposite results will be obtained. There is an optimal frequency for both situations to make best output performance.(2) For the FCSCVPPs with different flat cone angles, among the output performances of 25°, 30°, 45°and 60°, 25°pump has the best output characteristics. The bigger is the angle; the worse is the output performance. The smaller is the angle, the stronger is the pump self-suction. (3) For the same FCSCVPP, the output volume and pressure have direct relation with pump’s stimulation voltage.(4) For the FCSCVPPs with different chamber heights, stimulation frequency is different for each of them. The smaller flat cone angle has better output performance.6、FCSCVPP Glycerin-Water Mixed Fluid ExperimentsIn order to test valveless pump’s ability of conveying macromolecule and suspend kernel fluid, and further test the relationship between output performance and different types of flowing fluid, different viscosities glycerin-water mixed fluids are used as pump fluid. 100%, 90% and 50% glycerin-water mixed fluids are tested on the prototypes. Experiments show: FCSCVPP can not pump out 100% glycerin fluid at all; for the 90% glycerin-water mixed fluid, at high stimulate voltage, FCSCVPP can pump it out. but volume is low with almost no noise; for the 50% glycerin-water mixed fluid, FCSCVPP works fine without bubbles. All experiments show that smaller flat cone angle has better output performance.The FCSCVPP design is first time brought forward in this dissertation. According to related literature search, no same kind of piezoelectric pumps are published or studied in the world, it is a novel idea.更多还原