非对称坡面腔底无阀压电泵流场分析

Analysis of Flow Field of Piezoelectric Pump with Unsymmetrical Slopes Element

无阀压电泵需要外接用于产生单向流动流管,阻碍了压电泵的微小型化,针对这一缺点提出了非对称坡面腔底无阀压电泵,该压电泵将用于产生单向流动的部件——非对称坡面集成于泵腔的底部。对非对称坡面腔底无阀压电泵进行了计算机建模,基于商用Fluent12软件运用自定义函数(user defined functions,简称UDF)对压电振子运动形式进行了模拟;采用RNGκ-ε湍流模型对瞬态N-S方程进行了求解,分析了泵腔内流场;得出了从20°到70°不同坡面角度下的平均流量,在坡面角为20°时,可以得到最大平均流量为0.864 ml/min,并通过流量测量试验测得该泵的最大流量达到了8.6 ml/min。从仿真和试验的角度验证了该泵的可行性。

This research presented a piezoelectric pump with unsymmetrical slopes element（PPUSE） to overcome drawbacks existing in the common valveless piezoelectric pumps with stream tubes which was used to create the unidirectional flow and meanwhile the barriers to pump minimization.The type of piezoelectric pump arranged the unidirectional flow generating part： the unsymmetrical slopes element in the base of the chamber.A numerical modeling was conducted for the PPUWSE;the moving of piezoelectric vibrator was simulated by using user defined function（UDF） of the commercial software FLUENT12 and the flow field in the pump chamber was analyzed by using the solve method of transient state N-S functions based on turbulence model.As a result,the average flow rates of different slope angles ranging from 20 to 70 degree were calculated,among which the maximum average flow rate reaches 0.864 ml/min when the slope angle is 20 degree.Tests show that the maximum flow rate is 8.6ml/min.The feasibility of the pump was verified by both the simulation and the test.