## 3 Results and Discussions
### Analysis of Numerical Simulation
#### 3.1.3 Influence of the Spherical Coefficient on the Deposition Amount of Aerosol Particles  
From Figure 10, when \(\psi\) increases in the range of 0.73-0.91, \(n\) linearly increases in \(3.8\times 10^{-4}\)-7.2 \(\times\)\(10^{-4}\) kg/m\({}^{2}\) (\(d=10\)\(\upmu\)m), \(3.8\times 10^{-4}\)-7.2 \(\times\)\(10^{-4}\) kg/m\({}^{2}\) (\(d=20\)\(\upmu\)m), and \(3.8\times 10^{-4}\)-7.2 \(\times\)\(10^{-4}\) kg/m\({}^{2}\) (\(d=30\)\(\upmu\)m), respectively. Therefore, \(n\) changes with \(\psi\) by linear positive correlation law under the same \(d\), and \(n\) changes with the increase of d by the law of increases first and then decreases under the same \(\psi\). The main reasons for the above phenomena were as follows:  
1. Combining Equations (5)-(8), it could be seen that the larger \(\psi\) was, the smaller the force between aerosol particles and the air was;
2. When the aerosol particles follow the gas flow, the larger the \(\psi\) was, the smaller the drag force of the airflow on the aerosol particles was, the longer the velocity response time was, and the greater the inertial force of the aerosol particles was;
3. When the airflow by-passes the surface of the photovoltaic (PV) module, the airflow direction and velocity would all be changed greatly. At this time, the larger the \(\psi\) was, the easier it was for the aerosol particles to break away from the constraints of the airflow and then deposit on the surface of the photovoltaic (PV) module;
4. The specific surface area of aerosol particles decreases with the increase of \(d\), which leads to the decrease in the ratio of drag force to inertia force;
5. When \(d=10\)\(\upmu\)m, the drag force would play a leading role for a single aerosol particle. At this time, the aerosol particles had a good follow-up to the airflow, resulting in relatively more aerosol particles by-passing the surface of the photovoltaic (PV) module, so \(n\) was relatively small;  
Figure 7: (**a**) Velocity field. (**b**) Pressure field. (6) When \(d\) gradually increased to 20 \(\upmu\)m, the inertial force would play a dominant role for a single aerosol particle. At this time, the ability of aerosol particles to break away from the airflow was also enhanced, which led to a relative increase in \(n\); (7) When \(d\) continues to increase to 30 \(\upmu\)m, gravity would play a dominant role for a single aerosol particle. At the same time, relatively more aerosol particles settled to the ground before reaching the surface of the photovoltaic (PV) module, and only relatively few aerosol particles had deposited on the surface of the photovoltaic (PV) module. Figure 11 presents a cloud map illustrating the distribution of accumulated particle deposition on the surface of the photovoltaic field for various particle sizes. It can be observed that with an increase in particle size, the area with a particle deposition of 1.4 kg/m\({}^{2}\) on the ground is also increasing. Figure 11 illustrates that particles primarily settle on the near-ground side after reaching the component's surface. This is due to the lower airflow velocity distribution on the near-ground side surface, causing air micro clusters to stagnate in this area. The drag force of the air causes the loss of kinetic energy for particles entering this area. Additionally, the near-ground side surface represents a high-pressure area where particles experience irregular motion due to Brownian forces. This motion increases the likelihood of collision with the component surface, leading to settlement and accumulation. The drag force of the air on the particles decreases gradually as the sphericity coefficient increases. Particles entering the high-pressure area will move upward under the influence of inertia. Additionally, larger sphericity coefficients result in greater particle displacement. Figure 10: Distribution of particle deposition. Figure 9: Improved distribution map based on experiments.