## 4 Results and Discussion
### Dynamic Response of Different Drag Force in the Separation Region  
Figure 8 shows the displacement response of particles with different diameters after accelerating through the acceleration room under different drag forces, simulating a certain degree of vacuuming conditions. From Figure 8, the displacement of atmospheric particles in the \(X\)-axis direction increases as the drag coefficient decreases. The larger the particle diameter, the greater the displacement. The unit of resistance coefficient mu is N s/m\({}^{2}\) by default. The inflection point of the resistance coefficient mu is \(10^{-6}\). When the drag coefficient becomes smaller, the displacement of the particulate matter increases sharply, and the displacement changes quickly. In the Y direction, the displacement exhibits different response laws. When the vertical electric field is the same, as the particle size increases, the Y-direction displacement gradually increases from a negative displacement to a positive displacement. As the drag coefficient decreases, the particle displacement gradually increases. A positive displacement occurs when the particle diameter is small, and a negative displacement occurs when the particle diameter is large. The displacement gradually increases as the drag coefficient decreases. With the decrease of drag coefficient and the increase of particle diameter, the displacement of atmospheric particles gradually increased, and separation effect is achieved for particles with different diameters. Figure 8: Dynamic displacement response of horizontal electric field strength and particle diameter: **(a)**\(X\)-axis displacement response; **(b)**\(Y\)-axis displacement response. Figure 7: Particle diameter and displacement response: **(a)**\(X\)-axis displacement response; **(b)**\(Y\)-axis displacement response. Figure 9 shows the variation of atmospheric particle displacement with drag coefficient when the electric field strength in the X and Y directions is 433 V. From Figure 9, in the X direction, as the drag coefficient decreases, the displacement of atmospheric particles decreases continuously. As the diameter of particles increases, the displacement increases continuously, and the drag coefficient has a greater influence on the displacement of particles. In ideal conditions without restriction, the X displacement can reach up to 25.57 m. Additionally, as the drag coefficient decreases, the particle displacement changes from a straight line to a curve. In the Y-axis direction, as the drag coefficient decreases, both the positive and negative displacements increase. When mu is \(10^{-7}\), the effect of increasing displacement is obvious. To a certain extent, the phenomenon of separation between atmospheric particles is formed. Figure 10 shows the effect diagram of atmospheric particulate separation under a different drag coefficient. From Figure 10a, when the drag coefficient decreases, the displacement of atmospheric particles in the \(x\)-axis direction increases. The mu is \(10^{-6}\), which is the inflection point of the drag force coefficient. When the drag force coefficient changes again, the displacement of the particles increases sharply and changes rapidly. In the \(Y\)-axis direction, PM\({}_{2.5}\) moves upward, and the displacement is small, the maximum is 0.45 m. PM\({}_{10}\) maintains a small displacement, and the \(Y\)-axis displacement is small. PM\({}_{100}\) moves downward, and when mu is less than \(10^{-6}\), the displacement increases suddenly and drops sharply. Three kinds of particles are separated in space to achieve the particles separation purpose. Figure 10: Variation of the drag coefficient of particle separation displacement: (**a**) Displacement in the X direction; (**b**) displacement in the Y direction. Figure 9: Particle diameter and displacement response for the same drag coefficient: (**a**) \(X\)-axis displacement response; (**b**) \(Y\)-axis displacement response.