Abstract
The depletion dynamics of 1 µm and 2.5 µm SiO2 aerosol
particles inside a differentially heated cavity was
investigated experimentally using a cubical DIANA cavity
with two opposing isothermal vertical walls and adiabatic
top, bottom, front and back walls. The top, front and
back walls are made of glass to allow optical access for
different laser devices. The cavity atmosphere consisted
of air and the isothermal wall temperatures were set to
approximately 330.6 K and 291.3 K. The Rayleigh number of
the flow was approximately 109, indicating turbulent
conditions. The particle deposition rates were
investigated by measuring the intensity of the reflected
light from the particles and by using tapered element
oscillating microbalance to measure the change in
airborne particle mass concentration. The flow field in
the mid-plane joining the isothermal walls was
investigated using particle image velocimetry. Gas
temperature measurements were collected using K-type
thermocouple. The flow field and temperature measurements
described turbulent flow near the isothermal and
horizontal walls encircling the cavity stagnant core
region with a stratified temperature distribution.
Measurements indicated that the particle concentration at
any time was approximately uniform throughout the cavity
atmosphere. The measured depletion rate were compared to
the theoretical "stirred settling" model predictions.
While the decay rate of 2.5 µm particles was close to
that predicted by the theoretical "stirred settling"
model, it was found that 1 µm particles deposited two
times faster than the theory predicted.
Original language | English |
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Pages (from-to) | 73-87 |
Journal | Journal of Aerosol Science |
Volume | 100 |
DOIs | |
Publication status | Published - 2016 |
MoE publication type | A1 Journal article-refereed |
Keywords
- deposition
- enclosure
- experiment
- natural convection