We discuss a new phenomenon of turbulent thermal diffusion associated with turbulent transport of aerosols in the atmosphere and in laboratory experiments. The essence of this phenomenon is the appearance of a nondiffusive mean flux of particles in the direction of the mean heat flux, which results in the formation of large-scale inhomogeneities in the spatial distribution of aerosols that accumulate in regions of minimum mean temperature of thesurrounding fluid. This effect of turbulent thermal diffusionwas detected experimentally. In experiments turbulence wasgenerated by two oscillating grids in two directions of the imposedvertical mean temperature gradient. We used Particle Image Velocimetry(PIV) to determine the turbulent velocity field, and an Image Processing Technique based on an analysis of the intensity of Mie scattering to determine the spatial distribution of aerosols. Analysis of the intensity of laser light Mie scattering by aerosols showed that aerosols accumulate in the vicinity of the minimum mean temperature due to the effect of turbulent thermal diffusion.
在一篇ELSEVIER发表的题为“SARS-CoV-2 RNA detection in the air and on surfaces in the COVID-19 ward of a hospital in Milan, Italy”的文章中,首次提出了新冠病毒能通过物体表面及空气进行传播的理论,这对患者及医护人员的保护和公共卫生管理都具有深远意义。该研究结果进一步佐证了使用赛多利斯Airport MD8空气气溶胶采样器 有效采集监测新冠病毒的重要性,这对深入了解病毒传播途径及规避污染风险有重要作用。