In the present study, a 3D device-level numerical model is implemented via finite element method to assess the effects of design and operating parameters on the separation performance of a microscale acoustofluidic device. Elastodynamic equations together with electromechanical coupling at the piezoelectric actuators for the stress field within the solid parts, Helmholtz equation for the acoustic field within fluid, and Navier–Stokes equations for the fluid flow are coupled for the simulations. Once the zero-acoustic and flow fields are obtained, the trajectories of the particles are obtained by employing point–particle approach. The particle trajectories are simulated for many particles with different sizes released from random initial locations. Separation performances of the different cases are evaluated based on described metrics such as purity, yield, percentage of particle stuck in the channel, the force acting on the particles, residence time and separation parameter.

在本研究中，通过有限元方法实现了3D设备级数值模型，以评估设计和操作参数对微尺度声流体设备分离性能的影响。弹性动力学方程与压电致动器上的机电耦合一起用于固体零件内的应力场，Helmholtz方程用于流体内的声场，以及Navier-Stokes方程用于流体流动，以进行仿真。一旦获得了零声场和流场，就可以采用点-粒子方法获得粒子的轨迹。模拟了从随机初始位置释放的许多具有不同大小的粒子的粒子轨迹。