Revision as of 08:12, 21 November 2017 view source Stephen.kime (talk \| contribs) 205 edits No edit summary ← Older edit		Revision as of 08:14, 21 November 2017 view source Stephen.kime (talk \| contribs) 205 edits No edit summary Newer edit →
Line 7: The explicit finite volume solution scheme utilised in HPC is mass conserving and requires numerical convergence to a high precision. This differs to TUFLOW Classic, which can continue to simulate a model with high volume error due to it being an implicit finite difference scheme. For HPC to achieve numerical convergence and mass conservation it is not possible to run with a fixed timestep as TUFLOW Classic is able to. HPC must change and adapt the timestep to the conditions within a given cell at a given point in time. This is typically controlled by the water velocity, depth and/or turbulence. The need for adaptive timestepping in HPC and the equations that control the necessary timestep for numerical convergence are described further on our <font color="blue"><tt> HPC Adaptive Timestep </tt></font> Wiki page.<br> By default HPC is a 2nd order solution scheme (geographically) like Classic which is an update from the superseded TUFLOW GPU solution which is a 1st order finite volume solution scheme. <font color="red"><tt> This means that HPC utilises additional points within the cell to interpolate from. It could be considered like having an upstream (backward) and downstream (forward) point to interpolate from, as oppose to a single downstream (forward) point of the cell in TUFLOW GPU. This higher order scheme provides an improved accuracy of the finite volume derivative, which becomes particularly beneficial when solving the SWE across steep gradients and weirs.</tt></font><br> Multiple domain models are defined in TUFLOW using 2D domain blocks within the TCF file. Each domain block is defined using <font color="blue"><tt> Start 2D Domain </tt></font> <font color="red"><tt>== </tt></font> <tt> <name> </tt> and <font color="blue"><tt> End 2D Domain </tt></font> commands. Unique geometry control file, boundary condition file, initial water level, plot output and time step commands are defined within each domain block. All other commands (such as the boundary condition database, material file references, estry control file and simulation time and map output commands) are defined outside the above mentioned 2D domain blocks. An example TCF file is shown below. Line 8 to 13 represents the first 2D domain. Line 15 to 20 contain the second 2D domain block. <br>

HPC Introduction: Difference between revisions