Mass transfer coefficient is an important parameter in the process of mass transfer to reflect the degree of enhancement of mass transfer process in liquid–solid reaction and in non-reactive systems. In the present paper, a new computational model including both acoustic streaming and ultrasonic thermal effect is established to quantitatively calculate the ultrasonic enhancement on mass transfer coefficient in liquid–solid reaction. A nonlinear Helmholtz equation containing the cavitation effect is used in the model to calculate the acoustic pressure distribution in the reactor, and a fluid-thermal coupling CFD involving mass transfer process for KOH solution is conducted to obtain the distribution and time-dependence of the mass transfer coefficient in silicon–KOH reaction. Mass transfer coefficient on silicon surface with a transducer at frequencies of 100 kHz has been numerically simulated, indicating that the mass transfer coefficient has the maximum value near the center of the silicon wafer, and increases with reaction time. The mass transfer coefficient in the center of the silicon wafer is increased by 14.3% from 6.043 × 10⁻⁵ m/s to 6.908 × 10⁻⁵ m/s under ultrasound power of 50W during reaction time from 0.1 hour to 1 hour (the mass transfer coefficient without ultrasound changes from 2.525 × 10⁻⁶ m/s to 7.615 × 10⁻⁷ m/s). A set of control simulations shows that the enhancement of mass transfer coefficient comparing to the situation without ultrasound is mainly resulted from the acoustic streaming, while the increasing of mass transfer coefficient with time is due to the thermal effect of ultrasound. The mass transfer coefficients under transducer power of 10W and 30W are also calculated, indicating that the mass transfer coefficient is positively correlated with the ultrasonic power.

传质系数是传质过程中的重要参数，它反映了液固反应和非反应体系中传质过程的增强程度。在本文中，建立了一个新的计算模型，该模型包括声流和超声热效应，以定量计算超声对液固反应中传质系数的增强作用。在模型中使用包含空化效应的非线性Helmholtz方程来计算反应堆中的声压分布，并进行涉及KOH溶液传质过程的流热耦合CFD，以获得质量的分布和时间依赖性。硅-KOH反应中的迁移系数。用换能器在100 kHz频率下在硅表面上的传质系数进行了数值模拟，表明传质系数在硅片中心附近具有最大值，并随反应时间而增加。硅片中心的传质系数从6.043×10增加了14.3％^-5米/秒至6.908×10 ^-5米/下50W的超声功率时反应时间0.1小时s至1小时（传质系数，而不改变超声从2.525×10 ^-6米/秒至7.615×10 ^{- 7} m / s）。一组控制仿真表明，与没有超声的情况相比，传质系数的提高主要是由声流引起的，而随着时间的推移传质系数的增加是由于超声的热效应引起的。还计算了在10W和30W换能器功率下的传质系数，表明传质系数与超声功率呈正相关。