"Y"形流管无阀压电泵流量及流管流阻特性分析

目前已有无阀压电泵所采用的无移动部件阀要么结构复杂,要么会产生速度、压强变化显著的湍流流场,不利于应用在医疗、卫生、保健等领域进行活体细胞或长链高分子细胞的输送.针对这些问题,研制一种新型无阀压电泵--"Y"形流管无阀压电泵,并对其进行模拟及试验研究.结合医疗领域输血、输液工作的需要,分析当前几种典型无移动部件阀的优缺点,并介绍"Y"形流管无阀压电泵及其流管的特点.对"Y"形流管无阀压电泵进行理论分析,建立泵流量计算公式.基于有限元法对"Y"形流管内流体流动状态进行模拟,得到"Y"形流管内正反流压强变化规律及内部涡旋较锥形流管内涡旋小的结论,并计算得到"Y"形流管正反向流阻.对"Y"形流管无阀压电泵进行理论与试验流量的比较分析,结果表明,理论泵流量与试验泵流量的最小与最大相对误差分别为7%、13%,也证明了理论分析与数值模拟是正确的.

ANALYSIS OF THE PUMP VOLUME FLOW RATE AND TUBE PROPERTY OF THE PIEZOELECTRIC VALVELESS PUMP WITH Y-SHAPE TUBES

There exists serious problems in the no-moving-part valves (NMPV) used by the piezoelectric pump presently: being complex in structure or bringing on huge vortex whose pressure and velocity vary dramatically in the tubes, which will go against the aim of transporting living cells and the long-chain-macromolecule cells in the areas of medical treat- ment, sanitation and health care. Aiming at these problems, a new type of the piezoelectric pump-valveless piezoelectric pump with Y-shape tubes is developed, and simulative and experimental researches are applied on the pump. Combined with the needs of transporting blood and fluid in the area of medical treatment, the advantages and disadvantages of several typical no-moving-part valves are analyzed, and the properties of the piezoelectric pump with Y-shape tubes and its tubes are introduced. Theoretical analysis is applied on the pump and the theoretical formula of the pump flow rate is established. Based on the finite element method (FEM), the numerical simulation of the fluid flow situation inside the Y-shape tubes is carried out, the law of pressure change of the Y-shape tubes along the positive and reverse directions are obtained, and the conclusion that the vortex occurs in the Y-shape tube is much more feeble than that in the taper tubes, is obtained, the flow resistances of the Y-shape tubes are also calculated. A comparison is made between the theoretical and experimental flow rate for the pie- zoelectric valveless pump with Y-shape tubes, the results indi- cate that the minimum and maximum relative errors between the two results tam out to be 7% and 13% respectively. There- fore, the validity and correctness of the theoretical analysis and the numerical simulation are proved.