Significance   Aerosol particles refer to the solid, liquid or solid-liquid mixture particles suspended in the atmosphere caused by naturally formed or artificial factors, which are composed of metal powder, bioparticle, dust particle and so on. The analysis of the spatial structure and motion status of aerosol particles is of great significance for ecological environmental protection, climate change control and functional materials development. As an important means to study the spatial structure and motion status of aerosol particles, the aggregation model of aerosol particles is used to simulate the aggregated procedure of aerosol particles under different conditions, which is employed to explain its aggregation and physical mechanism. Aggregation models are widely used in optics, astronomical physics, dynamics and so on. The investigation on the mechanism, influential factors and application of aerosol particles aggregation model is beneficial to the optimization of aerosol particles aggregation model and the preparation of novel extinction materials.

  Progress  Firstly, the mechanism and main influential factors of aerosol particle aggregations are analyzed, such as particle spatial structure characteristics, the interaction of particles, and atmospheric environment. The theory of fractal, mathematical statistics and molecular simulation used in the study of aerosol particle aggregation are summarized. Secondly, based on the implementation methods of aerosol particle aggregation simulation, the classifications and characteristics of aggregation models are described. In addition, the application of the aerosol particle aggregation model in optics, astrophysics, and dynamics is mentioned. The model optimization such as algorithm efficiency, simulation modes, and application errors reduction is analyzed. Finally, in view of the current application status and challenges faced by aerosol particle aggregation models, the trend of aggregation models is proposed, such as the construction of a non-spherical particle aggregation model, application of multi-factor coupled aggregation model and simulation of real-time spatial distribution of aggregation particles, etc.

  Conclusions and Prospects  In recent years, the aerosol particle aggregation models have been used in a variety of areas. The aerosol particle aggregation model can be used to simulate the visual procedure of particle aggregation, study the formation mechanism and aggregation dynamics of particles, and carry out an in-depth analysis of aggregation characteristics. The aerosol particle aggregation model is important to analyze dynamics, morphology and other properties of aggregates. These models can be used to explain the phenomena such as gas mixture explosions and comet polarization. It can also provide a means for the screening and controllable preparation of extinction materials. However, there are still some shortcomings. Firstly, the complex morphology and structures of non-spherical particles are an important part of simulating and analyzing more realistic aerosol particle applications. The aggregation model of randomly oriented non-spherical aerosol particles with controllable particle shape and size has not yet been established. Secondly, the analysis of the aggregation mechanism of the model is relatively simple. To improve the accuracy of the simulation, the influence of multiple factors on the aggregation procedure needs to be considered. In addition, the simulation of real-time spatial distribution of the particles is acquired to further investigate in future. Therefore, the model can be optimized as followings. On the one hand, the aggregation models for of randomly oriented non-spherical aerosol particles can be analytically established. On the other hand, it can be revised in terms of multi-factor coupling and real-time spatial distribution of particles.