The Parameters tab sets the global system parameters. Note that these may also be specified in the data file. Any such values set within the data file (General System Parameters) will override the defaults in the 1D simulation window, although any values altered within the latter will take precedence.
The parameters, meanings and their default values are as follows:
| Parameter | Description | Default |
|---|---|---|
| Lower Froude Limit | Supercritical flow is approximately modelled by phasing out the ∂A/∂x part of the convective acceleration term in the momentum equation between the values Lower Froude Limit and Upper Frounde Limit. (Except in Direct Method Transcritical Solver) | 0.75 |
| Upper Froude Limit | Supercritical flow is approximately modelled by phasing out the ∂A/∂x part of the convective acceleration term in the momentum equation between the values Lower Froude Limit and Upper Frounde Limit. (Except in Direct Method Transcritical Solver) | 0.9 |
| Pivotal Choice Parameter | Parameter that specifies the degree of matrix pivoting. Should not be altered by the non-expert user (not available for steady direct runs) | 0.1 |
| Matrix Dummy Coefficient | Dummy coefficient to maintain the solution matrix structure. Should not be altered by the non-expert user (not available for steady direct runs) | 0 |
| Direct Method Convergence Parameter | Absolute flow and stage tolerance value used in Direct steady Method (not available for other run types) | 0.001 |
| Minimum Depth of water | Depth to which channel water depth is reset if it falls below this value (in metres) | 0.1m |
| Average Water Temperature | Water temperature (°C). Has no effect on hydraulic results | 10°C |
| Global Matrix Dummy Coefficient | Dummy coefficient to help maintain matrix structure within calculation engine. Setting to a small (positive) number may help improve matrix singularity issues. | 0 |
| Large results check | Option to check outputs from matrix solver. If values exceed specified upper limit then simulation is terminated and fatal error is generated | Off (no tick) |
| Upper flow bound | Upper limit for flow values output from matrix solver | 1 x 107 |
| Upper stage bound | Upper limit for stage values output from matrix solver | 1 x 105 |