TY  - JOUR
A1  - Voigtländer, Jens
A1  - Duplissy, Jonathan
A1  - Rondo, Linda
A1  - Kürten, Christoph Andreas
A1  - Stratmann, Frank
T1  - Numerical simulations of mixing conditions and aerosol dynamics in the CERN CLOUD chamber
T2  - Atmospheric chemistry and physics
N2  - To study the effect of galactic cosmic rays on aerosols and clouds, the Cosmics Leaving OUtdoor Droplets (CLOUD) project was established. Experiments are carried out at a 26.1 m3 tank at CERN (Switzerland). In the experiments, the effect of ionizing radiation on H2SO4 particle formation and growth is investigated. To evaluate the experimental configuration, the experiment was simulated using a coupled multidimensional computational fluid dynamics (CFD) – particle model. In the model the coupled fields of gas/vapor species, temperature, flow velocity and particle properties were computed to investigate mixing state and mixing times of the CLOUD tank's contents. Simulation results show that a 1-fan configuration, as used in first experiments, may not be sufficient to ensure a homogeneously mixed chamber. To mix the tank properly, two fans and sufficiently high fan speeds are necessary. The 1/e response times for instantaneous changes of wall temperature and saturation ratio were found to be in the order of few minutes. Particle nucleation and growth was also simulated and particle number size distribution properties of the freshly nucleated particles (particle number, mean size, standard deviation of the assumed log-normal distribution) were found to be distributed over the tank's volume similar to the gas species.
Y1  - 2012
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/25226
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-252263
UR  - http://www.atmos-chem-phys.net/12/2205/2012/acp-12-2205-2012.html
SN  - 1680-7324
VL  - 12
SP  - 2205
EP  - 2214
PB  - European Geosciences Union
CY  - Katlenburg-Lindau [u.a.]
ER  -