Numerical study of the human walking-induced fine particles resuspension

Resuspension of particles deposited by nano‐enabled consumer sprays: The role of product type, flooring material, and resuspension force

“…We can speculate that if this trend continues, there is a high likelihood that nanosized particles were also resuspended during all experiments. Although the number concentration of resuspended particles increases with decreasing particle size, the resuspension rate for those smaller particles is likely to decrease due to increased particle adhesion forces, which tend to keep particles attached to the floor surface 16,63–65 . This aspect of particle resuspension will be examined in a separate paper.…”

“…This is due to different moving strategies and the higher body weight of the adult experimenter compared with the robot, which resulted in higher resuspension force. In a typical walk by an adult, a tip vortex is developed at the edge of the shoe, and the flow from under the shoe is squeezed and ejected as a wall jet in front of and from both sides of the shoe 63 . Two counterrotating vortices are formed as the shoe touches the floor; they translate horizontally on the ground and slowly decay 63 .…”

“…In a typical walk by an adult, a tip vortex is developed at the edge of the shoe, and the flow from under the shoe is squeezed and ejected as a wall jet in front of and from both sides of the shoe 63 . Two counterrotating vortices are formed as the shoe touches the floor; they translate horizontally on the ground and slowly decay 63 . When the shoe moves upward, a strong suction flow is generated between the sole and flooring, leading to the transport of generated vortices 62 .…”

“…For example, high particle roughness results in higher resuspended particle concentrations 66 . For different particle and surface types, the thermodynamic work of adhesion is different, thus, different particles need to be provided a different amount of energy to be resuspended from the floor surfaces 63 . Also, as was illustrated in micrographs, the product matrix plays an important role.…”

“…66 particles need to be provided a different amount of energy to be resuspended from the floor surfaces. 63 Also, as was illustrated in micrographs, the product matrix plays an important role.…”