Improvement of Dust Particle Suction Efficiency by Controlling the Airflow of a Regenerative Air Sweeper  
[PERSON], 1,2, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30  
It is very important that street cleaners have high efficiency in absorbing dust and particles. For example, [PERSON] et al. [4] analyzed the mechanical behavior of dust particles and the relationship between the pressure distribution and dust particle velocity and obtained optimal performance parameters. According to [PERSON] et al. [5], increasing the width and outlet diameter of the pickup head affects the flow-field characteristics and dust suction efficiency. However, an increase in driving speed increases the relative speed between the dust particles and the inlet surface and causes dust particles to spill. By improving the design of the pickup, [PERSON] et al. [6] found that the pressure drops across the pickup head and the inclination angle of the rear edge wall have a significant impact on particle removal performance. They recommended the need to consider designing a pickup head with a high removal efficiency and low pressure drop. In a simulation study by [PERSON] et al. [7], the efficiency of particle assimilation was increased by changing the size of the suction mouth of the dust particles. [PERSON] and [PERSON] et al. [3,8] found that changing the outlet diameter and angle of the dust suction port resulted in a change in both the removal efficiency and flow field characteristics with an increase in the angle. The optimum angle was 65\({}^{\circ}\) and the outlet diameter was 160 mm. [PERSON] et al. [9] studied the factors affecting the particle suction efficiency. Higher efficiencies were achieved at higher sweeper speeds and higher particle densities by increasing the airflow rate at the suction port. At a sweep speed of 6-10 km/h, the results showed that the secondary air circulation changed from 60 to 80%, the high-pressure drop was from 2200 to 2400 Pa, and the recorded particle absorption efficiency was 95%. The structure and characteristics of the particles significantly affect the efficiency of dust particle suction in regenerative sweepers. Pickup velocity is another important parameter of interest in the design and performance of the pickup head. Particle entrainment was investigated by measuring the velocity required at the pickup head [10]. The dominant forces and particle size were the contributing factors that determined the magnitude of the pickup velocity. For example, larger particles demand a greater velocity at the pickup head, and vice versa. The critical pickup velocities of particles were experimentally studied by [PERSON] et al. [11] to evaluate the performance of the pickup head for varying particle shapes, sizes, and densities. It was observed that for large particles, the pickup velocity increased as the diameter increased, owing to the increase in gravitational force. Furthermore, [PERSON] et al. [12] provided a mechanical model that predicted the critical velocity required for the initial velocity of the particles in the solid layer. [PERSON] et al. [13] investigated the lift and drag forces acting on a spherical particle in a flow field bounded by a single wall, using numerical computations. Additionally, [PERSON] et al. [14] presented methods to improve dust removal performance by experimentally studying the effects of changes in dust composition on cleaning efficiency. Overall, the total dust and respirable dust removal efficiency were 96.81% and 95.59%, respectively. In recent years, the application of simulation and parametric analysis has improved the design structure and performance of pickup heads. The optimal solution can be achieved through simulation by reviewing the geometric design and the effects of parameters such as the width, outlet diameter, inlet pressure, and airflow velocity of road sweepers [5].