| TITAN2D | |
| Developer: | Geophysical Mass Flow Group |
| Latest Release Version: | 2.0.0 |
| Operating System: | Unix-like |
| Genre: | Geoflow Simulator |
| License: | NCSA Open Source License |
TITAN2D is a geoflow simulation software application, intended for geological researchers. It is distributed as free software.
TITAN2D is a free software application developed by the Geophysical Mass Flow Group at the State University of New York (SUNY) at Buffalo. TITAN2D was developed for the purpose of simulating granular flows (primarily geological massflows such as debris avalanches and landslides) overdigital elevation models (DEM)s of natural terrain.The code is designed to help scientists and civil protection authorities assess therisk of, and mitigate, hazards due to dry debris flows and avalanches.TITAN2D combines numerical simulations of a flow with digital elevation data of natural terrainsupported through a Geographical Information System (GIS) interface such as GRASS.
TITAN2D is capable of multiprocessor runs.A Message Passing Interface (MPI) ApplicationProgramming Interface (API) allowsfor parallel computing on multiple processors, which effectively increases computational power, decreases computing time,and allows for the use of large data sets.
Adaptive gridding allowsfor the concentration of computing power on regions of specialinterest. Mesh refinement captures the complex flow features that occur at the leading edgeof a flow, as well as locations where rapid changes in topography induce large mass and momentum fluxes. Meshunrefinement is applied where solution values are relatively constantor small to further improve computational efficiency.
TITAN2D requires an initial volume and shape estimate for the starting material, a basal friction angle, and aninternal friction angle for the simulated granular flow. The direct outputs of the program aredynamic representations of a flow's depth and momentum. Secondary or derived outputs include flow velocity, and such field-observable quantities as run-up height, deposit thickness, and inundation area.
The TITAN2D program is based upon a depth-averaged model for an incompressibleCoulomb continuum, a “shallow-water” granular flow. The conservation equationsfor mass and momentum are solved with a Coulomb-type frictionterm for the interactions between the grains of the media and between the granular materialand the basal surface. The resulting hyperbolic systemof equations is solved using a parallel, adaptive mesh,Godunov scheme. The basic form of the depth-averaged governing equations appear as follows.
The depth-averaged conservation of mass is:
{\underbrace{\partialh\over\partialt}} \begin{smallmatrixChange\\ inmass\\ overtime \end{smallmatrix}}+\underbrace{{\partial\overline{hu}\over\partialx}+{\partial\overline{hv}\over\partialy}} \begin{smallmatrixTotalspatial\\ variationof\\ x,ymassfluxes \end{smallmatrix}} =0
The depth-averaged x,y momentum balances are:
{\underbrace{\partial\overline{hu}\over\partialt}} \begin{smallmatrixChangein\\ xmassflux\\ overtime \end{smallmatrix}} +\underbrace{{\partial\over\partialx}\left(\overline{hu2}+{1\over2}{kap
| 2}\right) | |
| g | |
| zh |
+{\partial\overline{huv}\over\partialy}} \begin{smallmatrixTotalspatialvariation\\ ofx,ymomentumfluxes\\ inx-direction \end{smallmatrix}} =\underbrace{-hkapsgn\left({\partialu\over\partialy}\right){\partialhgz\over\partialy}\sin\phiint
{\underbrace{\partial\overline{hv}\over\partialt}} \begin{smallmatrixChangein\\ ymassflux\\ overtime \end{smallmatrix}} +\underbrace{{\partial\overline{huv}\over\partialx}+{\partial\over\partialy}\left(\overline{hv2}+{1\over2}{kap
| 2}\right)} | |
| g | |
| \begin{smallmatrix |
Totalspatialvariation\\ ofx,ymomentumfluxes\\ iny-direction \end{smallmatrix}} =\underbrace{-hkapsgn\left({\partialv\over\partialx}\right){\partialhgz\over\partialx}\sin\phiint