SEAMLESS-WAVE
SEAMLESS-WAVE is a developing “SoftwarE infrAstructure for Multi-purpose fLood modElling at variouS scaleS” based on "WAVElets" and their versatile properties. The vision behind SEAMLESS-WAVE is to produce an intelligent and holistic modelling framework, which can drastically reduce iterations in building and testing for an optimal model setting, and in controlling the propagation of model-error due to scaling effects and of uncertainty due statistical inputs.
Using the DG2-RANS solver
The DG2-RANS solver on LISFLOOD-F can be setup and run in a similar way as any other uniform-grid solver (see the Section “Input files and their format”), subjected to typing several extra parameters in the *.par file. These parameters are described in the table below.
Item name input |
Description |
|---|---|
| turbulent | Boolean keyword instructing LISFLOOD-FP to use turbulent flow simulator |
| laminar | Boolean keyword instructing LISFLOOD-FP to use laminar flow simulator (without turbulence fluctuations) |
| inviscid | Boolean keyword instructing LISFLOOD-FP to use Inviscid flow simulator (without turbulence fluctuations and viscous effects). This is the default flow solver, so if none of laminar, turbulent and inviscid are pointed in *.par file, then the inviscid flow will be considered. |
| DtRatioLimit | Keyword followed by a decimal number. It indirectly sets the upper bound limit for the turbulent (eddy) viscosity $D_t$ = DtRatioLimit × $D_m$ The default value is 10,000 which means $D_t$ =0.01. |
| TurbIntensity | Keyword followed by a decimal number. It is the turbulence intensity $I$ and is used in the turbulent inflow boundary condition calculations. It is between 0 to 20%. The default value is 1%. The guidance for its value: Low-turbulence cases: 0%<I≤1% Medium-turbulence cases: 1%<I≤5% High-turbulence cases: 5%<I≤20% |
| TurbViscousityRatio | Keyword followed by a decimal number. It specifies the turbulent viscosity ratio $D_r$ which is used in the turbulent inflow boundary condition calculation. It is usually $D_r$ < 10. Its default value is 0.1. |
| turboutput | Boolean keyword instructing LISFLOOD-FP to write out ASCII raster files of the turbulence-related variables $Hk$, H$\varepsilon$ and $D_t$. Their average values will be printed in files with the extensions of *.Hk, *.He and *.Dt. Their slope coefficients will be in files with the extensions of *.Hk1x, *.Hk1y, *.He1x and *.He1y. Without turboutput, there will not be any outputs for the turbulence-related variables. |
| startHkHe2d | Boolean keyword instructing LISFLOOD-FP to read initial condition files for Hk and H$\varepsilon$ in ASCII raster format. It will read files with the extensions of *.Hk, *.Hk1x, *.Hk1y, *.He, *.He1x and *.He1y. Without startHkHe2d, $k$ = $k_{tol}$ = $10^{-12}$ and $\varepsilon$ = $\varepsilon_{tol}$ = $10^{-12}$ will be used. |
| cavity_coarse | Boolean keyword instructing LISFLOOD-FP to simulate “Recirculation flow in sharp building cavities” benchmark test using the coarse grid (0.32 m). |
| cavity_fine | Boolean keyword instructing LISFLOOD-FP to simulate “Recirculation flow in sharp building cavities” benchmark test using the fine grid (0.16 m). |
By default, DG2-RANS will be launched on multicore units. Launching it on GPU needs typing the item cuda in the parameter *.par file (see the Section “Parameter file (.par)”.
The DG2-RANS solver is described in this paper, which futher explores the performance of DG2-RANS over four vortical shallow water test cases, listed below.
| Test case | Reynolds number | Snapshot |
|---|---|---|
| Laminar wake(s) past cylinder(s) | 200-220 |  |
| Vortex shedding past a conical island | 6,210 |  |
| Recirculation flow in sharp building cavities | 112,673 |  |
| Flow past a square block in a diverting T-junction | 7,432 |  |