声凝并中颗粒间相互作用研究进展

声凝并是细颗粒物(PM2.5)排放控制的重要技术途径,其通过外加声场作用促进PM2.5发生碰撞凝并,使得颗粒数目减少、粒径增大,从而提高后续除尘装置的效率。对声凝并中颗粒间的相互作用机理,包括同向相互作用、声尾流效应、互辐射压力效应、互散射效应的相关研究进行总结和评述,结合声凝并技术在PM2.5排放控制中的应用,指出已有研究在理论模型和实验观测上存在的问题,进而提出今后的研究应在实验方法上进行创新,发展出能够跟踪微米和亚微米尺度PM2.5颗粒或颗粒团相互作用过程细节信息的实验手段,为理论模型的实验验证提供数据支撑;同时应进一步发展理论模型,从而在模型验证的基础上,充分发挥数值模拟的优势,全面识别声凝并中颗粒间相互作用的动力学行为。

Research progress on particle interaction in acoustic agglomeration

Acoustic agglomeration is an important technical approach to control the emission of fine particles (PM_2.5). An external acoustic field can promote the particle collision and agglomeration, and make particle number decrease and particle diameter increase, hence the efficiency of the subsequent dust removal device can be improved. The relevant researches on the particle interaction mechanisms in acoustic agglomeration, including orthokinetic interaction, acoustic wake effect, mutual radiation pressure effect and mutual scattering effect are summarized and reviewed in this paper. Combined with the application of acoustic agglomeration technique in emission control of PM_2.5, the problems existing in the previous researches on theoretical models and experimental observations are presented. Based on this, a proposal of developing novel experimental approaches, which can track the detailed information of the interaction between micrometer and sub-micrometer sized PM_2.5 particles or particle agglomerates should be developed, is put forward in order to provide data support for the experimental verification of the theoretical models in further studies. Meanwhile, the theoretical model should be further developed, thus the dynamical behaviors of particle interaction in acoustic agglomeration can be comprehensively identified by taking full advantage of the numerical simulation on the basis of model validation.