声波对气溶胶和云雾粒子聚并影响研究进展

声波对气溶胶和云雾粒子聚并的作用和影响是当今云雾物理和人工影响天气领域研究的前沿科学问题。已有研究表明:声聚并机制主要包括同向团聚机制、流体力学机制（包括共辐射压效应、共散射效应和声波尾流效应）和声致湍流机制等；气溶胶粒子在声场中的聚并现象是在多种声聚并机制共同作用下出现的；低频强声波在声聚并机制作用下会增加云雾滴粒子之间的相对运动，促进粒子间的碰并过程，对云雾滴生长和降水过程有显著的影响。但由于声波聚并过程的复杂性、实验条件的多样性和理论的局限性，使声聚并效率最高的最佳实验条件和参数配置依然具有很大的不确定性，需要进行大量实验与数值模拟的综合研究。今后应加强声聚并对云雾滴作用的云室和数值模拟研究，并开展声波对云雾过程和降水影响的野外综合观测试验评估，这对发展人工影响天气（如人工消雾、增雨等）新技术有重要的科学意义。

A Review on the Effect of Sound Waves upon the Coalescence of Aerosol and Cloud and Fog Particles

The effect of sound waves on the coalescence of aerosol particles and cloud and fog droplets is a frontier scientific problem in the field of cloud physics and weather modification. The technology of acoustic coalescence has attracted much attention due to its relatively simple experimental device, strong adaptability, and short operation time. These advantages make it a potential new technology of aerosol coalescence. The research progress of acoustic coalescence of aerosol particles and cloud and fog droplets is reviewed from the aspects of theory, experiment, and numerical simulation. The mechanisms of acoustic coalescence mainly include orthokinetic interaction, hydrodynamic interaction (including acoustic wake effect, mutual radiation pressure effect, and mutual scattering effect), and acoustic-induced turbulence effect. The coalescence of aerosol particles in the sound field appears under the combined action. The low-frequency strong sound wave can increase the relative motion between cloud and fog droplets and promote the process of collision and coalescence, which has a significant impact on cloud and fog growth and precipitation. Finally, the existing problems and improvement direction of the research on the theory, experimental observation, and numerical simulation of acoustic coalescence are discussed. The complexity of the acoustic coalescence process, the diversity of experimental conditions, and the limitations of the theory, the optimal experimental conditions and parameter configuration for high efficiency of acoustic coalescence are still imperfect, which requires further experimental studies and numerical simulations. In addition, the research on the coalescence effect of sound waves on fog and cloud particles is not deep enough, and the similarities and differences of acoustic coalescence mechanisms between cloud and fog particles and ordinary aerosols are not clear enough. It is emphasized that the cloud chamber and numerical simulation research on the effect of acoustic coalescence on cloud and fog particles should be strengthened, and a large number of field comprehensive observation experiments should be carried out, which is of great scientific significance for the development of new weather modification technologies.