Transport of gases and particles to surfaces with widely spaced roughness elements

Radioactive gases and labelled particles have been used in wind tunnels to measure the effects of Reynolds and Schmidt numbers on transport to surfaces with widely spaced roughness elements. Good correlations are obtained for gases and for sub-micrometric sized particles, and the results can probably be extended to conditions in the open air. Deposition of larger particles is dominated by the effects of bounce off, which depends on surface conditions. This is also reflected in the pattern of deposition between roughness elements.