Computational modelling of geomorphic mountain flows based on multi-component shallow water theory
The three-year research programme pursues the development of novel modelling
tools for the description and prediction of geomorphic mountain flows. The approach
is based on a multi-component, shallow layer description of horizontal
two-dimensional flow. The overall programme aims to: 1) establish governing
equations accounting for the coupled motion of water, liquefied soil, and transported
sediment; 2) develop and implement suitable computational techniques; 3) test the
equations and computations against theoretical, experimental and field information.
As planned in the original proposal, work in the first year has concentrated on the
development of the theoretical framework and computational solver. The main
theoretical result is a set of general geomorphic flow equations which account for: 1)
separate sub-layers having their own density, velocity and rheology; 2) mass and
momentum exchanges across sub-layers as well as along and transverse to the flow; 3)
modes of support of the granular phase which include contact-load, pore-pressure
support, and turbulent suspension. From a computational point of view, the main
achievement has been the completion of a second-order accurate, two-dimensional
solver for two-layer flows, and its successful application to various geomorphic test
cases. The most interesting computation performed to date with the new solver has
been the simulation of an evolving field of antidune bedforms.
Further revisions to both the theoretical and computational methods will no doubt
prove necessary as we proceed. Nonetheless, the basic tools are ready for the next
steps planned for the second and third year of the programme. A key part of these
efforts will be to carry out detailed comparisons of model results with available
laboratory and field data.
|Appears in Collections:||土木工程學系|
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