一种新型无阀微泵的研究

研究了一种适用于微流体系统的新型无阀微泵.以单晶硅片为材料并采用微机电系统(MEMS)技术制备微泵的泵腔以及扩散口和喷口,选用弹性模量较小的聚二甲基硅氧烷(PDMS)作为泵膜,利用扁平振动马达作为驱动部件,研制出一个尺寸为12 mm×12 mm× 6 mm的无阀微泵.分别对微泵的振动频率和输出流量进行了测试,结果显示:...     

仿尾鳍压电双晶片无阀泵的模拟与试验

通过模仿金枪鱼的鱼体结构,将泵振子的摆动端设计成柔性小翼,使得振子摆动更接近于真实鱼尾的摆动.数值计算及激光扫频试验表明,压电层合结构悬臂梁的1阶振型机电转换效果最差,2阶和3阶的均能获得较好的机电转换效果.分析了振子在水中振动的固有频率和振型,并通过激光多普勒测振仪对振子的振动做了测振试验,数值计算得到的振型和激光扫频试验结果相一致.2阶和3阶的固有频率仿真结果和激光扫频结果分别相差1.6%和0.3%.研制了泵的样机并测量了激励电压在60V时泵的流量.振子工作在2阶振型时,谐振频率为740Hz,泵的流量为266mL/min.振子工作在3阶振型时,谐振频率为1280Hz,泵的流量为105mL/min.在相同电压激励下,泵的最大流量较同类型泵提高了160%.     

Theory and experimental verification on valveless piezoelectric pump with multistage Y-shape treelike bifurcate tubes

Among most traditional piezo water cooling systems, piezoelectric valve pumps are adopted as their driving sources. The valves in these pumps induce problems of shock and vibration and also make their structure complicated, which is uneasy to minimize and reduce their reliability and applicability of the whole system. In order to avoid these problems caused by valve structure, a novel valveless piezoelectric pump is developed, which integrates both functions of transforming and cooling. The pump’s Y-shape tree-like construction not only increases the efficiency of cooling but also the system reliability and applicability. Firstly, a multistage Y-shape treelike bifurcate tube is proposed, then a valveless piezoelectric pump with multistage Y-shape treelike bifurcate tubes is designed and its working principle is analyzed. Then, the theoretical analysis of flow resistance characteristics and the flow rate of the valveless piezoelectric pump are performed. Meanwhile, commercial software CFX is employed to perform the numerical simulation for the pump. Finally, this valveless piezoelectric pump is fabricated, the relationship between the flow rates and driving frequency, as well as the relationship between the back pressure and the driving frequency are experimentally investigated. The experimental results show that the maximum flow rate is 35.6 mL/min under 100 V peak-to-peak voltage (10.3 Hz) power supply, and the maximum back pressure is 55 mm H2O under 100 V (9 Hz) power supply, which validates the feasibility of the valveless piezoelectric pump with multistage Y-shape treelike bifurcate tubes. The proposed research provides certain references for the design of valveless piezoelectric pump and improves the reliability of piezo water cooling systems.     

无阀压电泵的流固耦合仿真及试验验证

提出利用结构分析软件ANSYS和流体分析软件ANSYS CFX对无阀压电泵进行流固耦合仿真分析,以研究无阀压电泵的输出性能。分别对进口在中间出口在一侧、出口在中间进口在一侧、进出口对称布置的3种不同结构形式的无阀压电泵进行了流固耦合仿真分析。结果显示,上述3种无阀压电泵中,出口在中间进口在一侧结构形式的无阀压电泵的宏观输出流量最大。制作了3种无阀压电泵的试验样机,并搭建了相应的试验测试系统,在幅值为45 V、频率为0~700Hz的正弦信号激励下对其输出流量进行了测试。结果表明,3种不同结构形式的无阀压电泵的最大输出流量分别为3.8、6.0和4.0ml/min,出口在中间进口在一侧的压电泵输出流量最大,与流固耦合仿真分析的结果相吻合,验证了本文提出的流固耦合仿真分析的方法可以指导压电泵的设计。     

Numerical simulation of a thermal-bubble actuated diffuser-nozzle valveless pump

A valveless micropump actuated by thermal bubbles which are generated by an electrode heater mounted with a pair of diffuser nozzles has been numerically studied by commercial CFD software FLUENT. The relationships between the net flow rate and the superheating and heat supplying frequency have been investigated. The depth of the diffuser-nozzle micropump is 200 μm, the diameter of the actuating chamber is 1 mm, and a pair of diffuser nozzles whose gap has been expanded from 30 μm to 274 μm with an open ang...     

无阀控自配流液压冲击器系统建模与仿真

提出一种新型无阀控自配流液压冲击器,分析了它的结构原理及特点。分别建立了冲击器回程和冲程时的数学模型;运用AMESim建立仿真模型并进行动态仿真,根据仿真曲线详细分析了系统供液流量及氮气腔初始充气压力对冲击器工作性能的影响。结果表明:在氮气腔初始充气压力一定时,供液流量必须达到一定值才能启动冲击器,在一定范围内,会出现使冲击性能最佳的流量值;当供液流量一定时,氮气腔初始充气压力较低时,冲击能和冲击效率较低;充气压力过高时,冲击器无法开启。该冲击系统在供液流量为75L/min、氮气腔初始充气压力为2.0MPa时,冲击性能最佳。     

数字化无阀微泵内微流体泵送运动的理论解析

对研制出的新型基于微流体数字化技术的数字化无阀微泵的泵送实验现象进行理论分析研究。提出数字化无阀微泵内的微流体概念,该微流体受外加周期性扰动,其边界流和中间流间产生速度差异,由于粘性力、惯性力交替作用,使微流体运动,中间流克服表面张力的作用得以喷射出去,实现数字化无阀微泵泵送。推导了中间流的运动公式,分析认为中间流与边界流存在着滞后效应,调整扰动周期长短,可实现离散流、连续流。     

扁平振动电机驱动的无阀微泵的研究

研制了一种新型的电磁驱动式无阀微泵,该微泵利用有机玻璃制作泵腔,采用扩散口/喷口的结构,以PDMS作为振动膜,利用扁平振动电机作为驱动部件.对微泵的振动频率和输出流量进行了测试,结果显示,电压在1.0 V～1.8 V范围内时,微泵的输出流量随着电压的升高而增加,当电压在1.8～3.3 V时,微泵输出的流量保持稳定,达到150 μL/min.具有良好的性能和低廉的成本.     

无阀滤池进水辅助控制调阻原理

论述了无阀滤池进水系统调阻控制原理．该原理通过调节进水系统的局部阻力，利用一套机构实现自动停水和阻止进气两种功能，使取消传统的Ｕ形进水管成为可能．试验证明：根据该原理研制的调阻式进水控制阀，不仅能灵敏可靠地完成自动停水和阻气功能，而且实施方便，宜于推广．     

无阀微泵泵腔中流体流动的有限元模拟与分析

采用有限元仿真软件ANSYS/FLOTRAN对收缩/扩张型无阀微泵泵腔中流体流动的全过程进行了数值模拟和仿真分析,得到了流体在整个泵腔中的流场构形和流动特性。结果表明,泵腔结构单元的弯道效应与出/入口处流体速度分布的非线性混合将导致腔中的局域涡流现象。通过对3个简单模型的模拟计算,证明了缓冲腔的不同结构对无阀微泵的整流效率有较大影响,是泵腔结构参数优化设计不可忽视的重要环节。