TUFLOW General Discussion: Difference between revisions

 

=Frequently Asked Questions (FAQ)=

The implicit and explicit solutions are numerical methods allowing to move from a continuous to discrete model of the world in which quantities are computed at a finite number of points in distance and time (mesh or grid), approximating the partial differential equation by a system of algebraic equations.<br>

 

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A finite difference scheme considers the solution data at discrete points (or nodes) in space and attempts to compute the time derivatives based on the solution data and its spatial derivatives evaluated at those discrete points. While this approach can be relatively simple to implement, the solution is often non-conservative, i.e. the total sum of a certain property (that should be conserved) over all points in the model might increase or decrease slightly from one timestep to the next even in the absence of internal sources or boundary fluxes.<br>

Tuflow HPC utilises an explicit finite volume scheme. This means that it has to use smaller timesteps and is guaranteed to capture the shortest time-scale physics that the given spatial resolution admits. The solution is conserving of mass and momentum to numerical precision. The scheme is not as computationally efficient as the implicit finite difference scheme of TUFLOW classic, if forced to execute on a single CPU core it is many times slower than classic. However, as the cell-by-cell computation of fluxes and derivatives are completely independent, the scheme is well suited to utilise highly parallelised compute hardware such as modern GPUs. The end result is that with a good GPU, TUFLOW HPC can be up to 100 times faster than classic for some models.<br>

 

== Do I require a TUFLOW licence to create TUFLOW inputs and view results from a TUFLOW simulation? ==