Abstract
The large-eddy simulation (LES) of a volcanic plume based on a multi-fluid approximation was performed. After the impact of subgrid scale (SGS) turbulence models on the structure of a volcanic plume was assessed, the transport process of volcanic ash inside a plume was investigated. The simulation results showed that the selection of SGS turbulence models could lead to impact on the plume structure such as the plume height and ascending velocity. Concerning the transport process of volcanic ash, the spatial distributions of particles with different sizes was not identical mainly because of the difference in mean vertical velocity. This supports the validity that the sedimentation rate is used as a parameter in existing source term models for long-range transport simulation of volcanic ash. However, this also suggests that existing source term models based on the one-fluid approximation can cause considerable approximation error for large particles.
