TUFLOW 2D Cell Size Selection: Difference between revisions

The run time results from this test case highlight a useful relationship used by modellers who wish to estimate likely simulations times for models that use a higher resolution than that presently simulated. The simulation time trend is as follows:

* A factor 2.0 increase in model resolution (eg. increasing the resolution from 30ft to 15ft) will increase the simulation time by a factor of 8.0.

In basic terms this relationship is due to doubling the resolution (halving the cell size) increasing the number of cells by a factor (4) four and requiring half the timestep to maintain stability (i.e. 2 two times the number of calculations) (4x2=8). The ratios for this test case don't match the above generalised trend exactly, though are close enough to be useful when optimising the cell size to meet project requirements.<br>

[[File:Mesh Converge Direct Rainfall Simulation Time Factor.png|700px]]