HPC FAQ: Difference between revisions

HPC solver uses a finite volume scheme which is volume conservative and shouldn't produce any mass error for 2D only models. Mass error can still occur when coupling HPC with the ESTRY engine that isn't volume conservative. The cause could be 1D structures, 1D/2D linking or 1D/2D timestep synchronisation. Where there is not a one to one synchronisation of the 1D and 2D timesteps, mass error may occur due to the interpolation of the 1D/2D boundary values over time.<br> A 'healthy' model will usually report up to 1% mass error. Higher mass error is an indication the solution is not converging, usually in isolated locations. In nearly all cases it is because of poor data (e.g. cliff edge between data sets) or model schematisation (e.g. large pit connected to one tiny 2D cell or boundary poorly digitised so it is not roughly perpendicular to the flow). The total model mass error can also be observed in the TUFLOW Summary File (*.tsf) output as oppose to the tlf file.