涡旋阀压电泵内部空化流动的数值分析

设计了一涡旋阀压电泵,采用动网格模型对其进行数值分析.首先对涡旋阀压电内部流场进行了动态模拟,得到了不同时期压电泵内的速度和静压分布图,有效地将压电振子的动态特征和流体的运动特征进行了间接流固耦合分析,验证了动网格模型在研究压电泵运动边界方面的可行性.研究了驱动频率,压电振子振幅,泵腔高度对涡旋阀压电泵输出性能的影响,发现驱动频率越小,压电振子振幅越大,出口体积流量越大,泵腔高度约为250μm,出口流量达到最大值.此外,还分别对涡旋阀和涡旋阀压电泵进行了空化模拟,得到了空化时涡旋阀内和不同时刻泵腔中的气液分布,为有效预测压电泵腔内空化,抑制空化现象提供了一定依据.

Numerical analysis of cavitation flow in vortex-valve piezoelectric micropump

A vortex-valve piezoelectric pump was proposed, and numerical analysis was done to simulate it by using dynamic mesh model. Dynamic simulation was carried on the piezoelectric pump to get the in- ner flow fields, thus the velocity profiles and pressure distributions in the pump at different processes were obtained. The dynamic mesh model effectively simulates the fluid-solid coupling dynamic characteristic between the piezoelectric vibrator and fluids, which demonstrates its feasibility in simulating moving boundary of piezoelectric pump. Dynamic mesh model was also applied to study the effect of driving fre- quency, amplitude of piezoelectric vibrator and height of pump chamber to pump output performance. It is found that when driving frequency decreases, the vibrator amplitude and the pump volume flow rate in- creases,while the flow rate reaches maximum as pump chamber is about 250 txm high. Cavitation simula- tion was also carried on the vortex-valve and the whole pump, and vapor-liquid distributions at different moments were obtained, providing some basis for prediction for cavitation phenomenon in piezoelectric pump and looking for cavitation prevention methods.