Study on high span motion characteristics and drag coefficient of airborne dust particles

Abstract

Based on the theory of molecular dynamics and thermodynamics, the dynamics model of the large span dust particles in the air of the earth surface with the size of 10 -7 ~10 -5 m was established, and the air drag coefficient of the particles under the model was obtained. The motion characteristics of spherical, cube and bicone particles in the model are studied by numerical analysis. In the process of falling, the drag coefficient gradually increases, and the air resistance is not proportional to the speed of movement. For a particle of the same shape, the time it takes to fall to the ground is affected by its size radius and the temperature of the air at the ground. The smaller the particle size radius (the decrease of gravity and air resistance at the same time), the higher the surface air temperature, the longer the time to fall to the ground.