Atmospheric Deposition Velocity

SYS

Deposition velocity is the physics term for the rate at which airborne particles — spores, pollen, soot, salts — transfer from the atmosphere onto a surface, governed by particle size, settling (Stokes) dynamics and near-surface turbulence. In the ATH atmospheric-vector field (AEBEM) it is one of the equations (with Stokes drag, settling velocity and Stokes number) that determine species-specific transport and where contaminant load concentrates on a building. Coupled with architectural aerodynamics it explains why soffits, recessed entrances and low-pressure eddy zones become colonisation 'hot spots', and it feeds the Time-to-Failure scheduling signal that times a property's clean to its real deposition regime (e.g. M1-corridor soot, agricultural dust).

turbulent mass transfer

Deposition velocity is the physics term for the rate at which airborne particles — spores, pollen, soot, salts — transfer from the atmosphere onto a surface, governed by particle size, settling (Stokes) dynamics and near-surface turbulence. In the ATH atmospheric-vector field (AEBEM) it is one of the equations (with Stokes drag, settling velocity and Stokes number) that determine species-specific transport and where contaminant load concentrates on a building. Coupled with architectural aerodynamics it explains why soffits, recessed entrances and low-pressure eddy zones become colonisation 'hot spots', and it feeds the Time-to-Failure scheduling signal that times a property's clean to its real deposition regime (e.g. M1-corridor soot, agricultural dust).