中文摘要：

以有阀压电泵为应用主流的电子芯片水冷散热系统，因存在阀体的结构原因增加了系统的体积，而且也会因阀体疲劳、失效和性能不稳定等因素影响其可靠性和使用寿命；同时，也还会产生噪声。由于类分形 Y 形分叉流管无阀压电泵具有简单的二维半的加工特性及逐级分叉流动能够覆盖更广域面积而产生极佳散热效果可以避免传统有阀压电泵的缺点。介绍类分形Y形分叉流管无阀压电泵的结构及工作原理；利用分形原理对类分形Y形分叉流管的流阻特性进行分析；同时，对类分形Y形分叉流管无阀压电泵进行数值计算与分析，得到该泵进出口间压差与流量关系；制作类分形Y形分叉流管无阀压电泵样机，并对该泵进行流阻和压差试验。试验结果表明，相同压差下，沿流管分流方向流动的出口流量大于合流时的出口流量；当进出口间压差为196 Pa时，试验值与模拟值存在最大相对误差，分流时，为90%，合流时，为89%；当驱动电压为100 V，驱动频率为9 Hz时，泵压差达到最大，为637 Pa。所做研究证明了类分形Y形分叉流管无阀压电泵分流和合流流阻不等，同时也验证了该泵的有效性。

英文摘要：

Most piezoelectric pumps employed in water cooling systems contain internal valves which increase the volume of the systems, affect the reliability of the pump, and cause noise. As valveless piezoelectric pump with fractal-like Y-shape branching tubes has simple processing characteristics of 2.5 dimensions, and multi-leveled braching flow can cover larger area which produces excellent heat dissipation, which can avoid shortcoming of traditional valve piezoelectric pump. Structure and working principle of valveless piezoelectric pump with fractal-like Y-shape branching tubes are introduced. Then, flow resistance characteristics of fractal-like Y-shape branching tube is analyzed by using fractal principle. Meanwhile, finite element software is employed to simulate the flow field of the pump, and the relationships between pressure drop and flow rate in inlet and outlet of this pump are obtained. Valveless piezoelectric pumps with fractal-like Y-shape branching tubes are fabricated, and flow resistance and back pressure experiments are conducted. The experimental results show that, the export flow rate along dividing flows is larger than merging flows at the same pressure drop. The maximum relative error between experimental and simulated results occurs, when pressure drop between inlet and outlet is 196 Pa, which is 90%and 89%along dividing and merging flows respectively. And the maximum back pressure of the valveless pump is 637 Pa under 100 V （9 Hz） power supply. The proposed researches ensure that flow resistances between merging and dividing flows are unequal and also validate the feasibility of the valveless piezoelectric pump with fractal-like Y-shape branching tubes.