压电振子激励流场的数值模拟

Numerical Simulation of Flow Fields Actuated by Piezoelectric Fans

关键词:  压电振子  非定常流动  相干性  数值研究 

Key words:  Piezoelectric fan  Unsteady flow  Coherence  Numerical simulation

摘要:

为了得到多个压电振子的相干性和涡系之间相互干涉的流场信息,探索间距和相位差等因素对多个压电振子耦合流场的影响效果,本文对单个与多个压电振子的非定常流场特性进行了数值模拟研究。结果表明,压电振子振动时,流场中出现了速度涡区,单个振子的涡系发展最充分,流场中速度峰值达4m/s,三个振子的垂直方向作用范围最大,但速度峰值只有2.8m/s；振子振幅 为A,振子间距在1A~4A,流场掺混效果与振子间距成正比,有1/2相位差时流场掺混效果优于无相位差的情况；多个振子产生的耦合射流效果在适当的间距与相位差下好于单个振子产生的射流。 

Abstract:

In order to get the coherence between multiple fans and the flow field information of vortex system and to study the effects of different space and phase difference on flow field in multiple-fan cases, numerical simulation was carried out to illustrate unsteady flow characteristics of multiple fans. The results show that velocity vortex is observed in the flow field when the fans vibrate. The vortex system of single fan flow field is most fully developed, and the peak velocity is 4m/s. The widest action range in vertical direction is observed in the three-fan flow field, while its peak velocity is only 2.8m/s. The oscillator amplitude was defined as A. When the oscillator spacing ranges from 1A to 4A,the flow field mixing effectiveness is proportional to the space between two fans, and the mixing effectiveness in the flow field with 1/2phase difference between two fans is better than that without phase difference. The coupling effect of multiple jets with appropriate space and phase difference is better than the flow field of a single fan. 