Publication Date:
2017-04-04
Description:
We develop a model to describe ash aggregates in a volcanic plume. The model is
based on a solution of the classical Smoluchowski equation, obtained by introducing a
similarity variable and a fractal relationship for the number of primary particles in an
aggregate. The considered collision frequency function accounts for different mechanisms
of aggregation, such as Brownian motion, ambient fluid shear, and differential
sedimentation. Although model formulation is general, here only sticking efficiency related
to the presence of water is considered. However, the different binding effect of liquid
water and ice is discerned. The proposed approach represents a first compromise between
the full description of the aggregation process and the need to decrease the computational
time necessary for solving the full Smoluchowski equation. We also perform a
parametric study on the main model parameters and estimate coagulation kernels and
timescales of the aggregation process under simplified conditions of interest in
volcanology. Further analyses and applications to real eruptions are presented in the
companion paper by Folch et al.
Description:
Published
Description:
B09201
Description:
3.6. Fisica del vulcanismo
Description:
4.3. TTC - Scenari di pericolosità vulcanica
Description:
JCR Journal
Description:
reserved
Keywords:
volcanic
;
Theoretical formulation
;
01. Atmosphere::01.01. Atmosphere::01.01.04. Processes and Dynamics
;
01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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