TY - JOUR
T1 - The effect of mixing rates on the formation and growth of condensation aerosols in a model stagnation flow
AU - Alshaarawi, Amjad
AU - Bisetti, Fabrizio
N1 - KAUST Repository Item: Exported on 2020-10-01
PY - 2015/3
Y1 - 2015/3
N2 - A steady, laminar stagnation flow configuration is adopted to investigate numerically the interaction between condensing aerosol particles and gas-phase transport across a canonical mixing layer. The mixing rates are varied by adjusting the velocity and length scales of the stagnation flow parametrically. The effect of mixing rates on particle concentration, polydispersity, and mean droplet diameter is explored and discussed. This numerical study reveals a complex response of the aerosol to varying flow times. Depending on the flow time, the variation of the particle concentration in response to varying mixing rates falls into one of the two regimes. For fast mixing rates, the number density and volume fraction of the condensing particles increase with residence time (nucleation regime). On the contrary, for low mixing rates, number density decreases with residence time and volume fraction reaches a plateau (condensation regime). It is shown that vapor scavenging by the aerosol phase is key to explaining the transition between these two regimes. The results reported here are general and illustrate genuine features of the evolution of aerosols forming by condensation of supersaturated vapor from heat and mass transport across mixing layers.
AB - A steady, laminar stagnation flow configuration is adopted to investigate numerically the interaction between condensing aerosol particles and gas-phase transport across a canonical mixing layer. The mixing rates are varied by adjusting the velocity and length scales of the stagnation flow parametrically. The effect of mixing rates on particle concentration, polydispersity, and mean droplet diameter is explored and discussed. This numerical study reveals a complex response of the aerosol to varying flow times. Depending on the flow time, the variation of the particle concentration in response to varying mixing rates falls into one of the two regimes. For fast mixing rates, the number density and volume fraction of the condensing particles increase with residence time (nucleation regime). On the contrary, for low mixing rates, number density decreases with residence time and volume fraction reaches a plateau (condensation regime). It is shown that vapor scavenging by the aerosol phase is key to explaining the transition between these two regimes. The results reported here are general and illustrate genuine features of the evolution of aerosols forming by condensation of supersaturated vapor from heat and mass transport across mixing layers.
UR - http://hdl.handle.net/10754/564072
UR - https://linkinghub.elsevier.com/retrieve/pii/S0021850214001803
UR - http://www.scopus.com/inward/record.url?scp=84916889727&partnerID=8YFLogxK
U2 - 10.1016/j.jaerosci.2014.11.004
DO - 10.1016/j.jaerosci.2014.11.004
M3 - Article
SN - 0021-8502
VL - 81
SP - 34
EP - 46
JO - Journal of Aerosol Science
JF - Journal of Aerosol Science
ER -