HPC FAQ: Difference between revisions

* “Minimum dt” map output (excellent for identifying the location of the minimum timestep adopted – add “dt” to “Map Output Data Types ==”)

 

Yes! TUFLOW Classic tells you where your model has deficient or erroneous data, or where the model is poorly set up by going unstable, or producing a high mass error (a sign of poor numerical convergence of the matrix solution). The best approach when developing a Classic model is to keep the timestep high (typically a half to a quarter of the cell size in metres), and if the simulation becomes unstable to investigate why. In most cases, there will be erroneous data or poor set up such as a badly orientated boundary, connecting a large 1D culvert to a single SX cell, etc.

HPC, however, remains stable by reducing its timestep and does not alert the modeller to these issues. Therefore, the following tips are highly recommended, otherwise there will be a strong likelihood that any deficient aspects to the modelling won’t be found till much further down the track, potentially causing costly reworking. So, it’s very much modeller beware!