param.ini - Sections [Mesh-M1-*]
Several sets of parameters can be configured in the same file.
Info
If new sets are to be introduced, new names should be chosen as a section name can only be used once.
Below, two sets of parameters are configured for the mesher M1 (sample1 and sample2). Sets of parameters are only described with one entry, defining "resfine" (all other variables will be configured with default parameters).
[Mesh-M1-default]
comment="default for all"
nsect=72
diaref=-1
diadom=-1
resfine=30.
rescoarse=-1
resratio=4
resdist=200.
Below, possible parameters for the mesher are enumerated and described.
nsect - number of computable directions
Drives the nodes location near boundaries, allowing the specified number of computable directions.
nsect=72
; number of computable directions [-]
; integer
; validty: in [8,12,16,18,24,36,48,72,90,120,144,180,240,360]
; default: 72
diaref - refined zone diameter
Defines the central zone area where the mesh is to be refined.
diaref=-1
; refined zone diameter [m]
; float > 0. ; if < 0: automatic evaluation
; validity: diaref ≤ diamin + 100.
; default: -1
Automatic evaluation
diaref is set using expression: diaref = diamin + 2000.
diamin refers to the reference size of the project
diadom - domain diameter
Defines the diameter of the computation domain.
diadom=-1
; computation domain diameter [m]
; float > 0. ; if < 0: automatic evaluation
; validity: diaref + 5000. ≤ diadom ≤ 100000.
; default: -1
Automatic evaluation
diadom is set using expression: diadom = diaref + 20000.
resfine - fine resolution criterion
Defines the refined horizontal mesh resolution for the "Fine" mesh version.
resfine=30.
; fine resolution criterion [m]
; float > 0. ; if < 0: automatic evaluation
; validity: 1. ≤ resfine ≤ 250.
; default: 25.
Automatic evaluation
Automatic evaluation ⇒ resfine evaluated iteratively from specified meshlim condition
rescoarse - coarse resolution criterion
Defines the refined horizontal mesh resolution for the "Coarse" mesh version.
rescoarse=-1
; coarse resolution criterion [m]
; float > 0. ; if < 0: automatic evaluation
; validity: 1. ≤ rescoarse ≤ 500.
; default: -1
Automatic evaluation
When resratio == 1 ⇒ rescoarse is set using expresion: rescoarse = 2 × resfine
When resratio > 1 ⇒ rescoarse is set using expresion: rescoarse = resratio × resfine
Warning
When consistent_grids is set to True, rescoarse is forced to resfine.
resratio - heterogeneous refinement ratio
Defines the ratio between the resolution applied at refined central zone and the resolution applied at entity-related zones.
resratio=4
; heterogeneous refinement ratio [-]
; integer
; validity: 1 ≤ resratio ≤ 20
; default: 4
Info
When resratio is set to 1, it results in a homogeneous refinement over the refined zone diameter.
resdist - heterogeneous refinement distance
Drives the size of the refined areas surrounding each entity.
Note
This parameter is only used when resratio > 1.
resdist=200.
; heterogeneous refinement distance [m]
; float
; validity: 100. ≤ resdist ≤ 1000.
; default: 200.
multizone - multiple refinement criterion
Activates multiple refinement zones.
multizone=False
; multiple refinement criterion [-]
; boolean
; validity: in [True, False]
; default: False
Info
When set to False, one single refinement zone is generated.
contcrit - high slopes refinement criterion
Activates the use of the high slope contours for defining the refined areas.
contcrit=False
; high slopes refinement criterion [-]
; boolean
; validity: in [True, False]
; default: False
meshlim - number of cells criterion
Defines the maximal number of cells for the targeted mesh.
Note
This parameter is only used when resfine is defined with a negative value.
meshlim=(MEMMAX-0.1*MEMMAX)/1.e+6
; number of cells criterion [Millions of Cells]
; float
; validity: 0.1 ≤ meshlim ≤ 200.
; default: (MEMMAX-0.1*MEMMAX)/1.e+6
Info
MEMMAX is the local amount of RAM in kB.
relax_distratio - relaxation distance ratio
Defines the distance ratio from diamin to diadom to locate the relaxation.
relax_distratio=0.5
; relaxation distance ratio [-]
; float
; validity condition: 0.5 ≤ relax_distratio ≤ 0.9
; default: 0.5
relax_resfactor - relaxation factor
Defines factor applied to resfine to drive the relaxed mesh resolution.
relax_resfactor=20;
; relaxation factor [-]
; float
; validity: 2. ≤ relax_resfactor ≤ 100.
; default: 20.
Which effects?
The highest relaxation factor, the less cells for the resulting mesh.
The highest relaxation factor, the less accuracy for the flow model runs.
consistent_grids - consistent grids criterion
Defines if Coarse and Fine mesh versions should be forced to share the same ground nodes distribution.
consistent_grids=False
; consistent grids criterion [-]
; boolean
; validity: in [True, False]
; default: False
Info
When activated, vertical discretization solely drives the variations between the Coarse and Fine mesh versions.
What for?
This parameter was introduced in order to have smoother transitions between Coarse and Fine runs.
It was introduced as some robustness troubles were found after remapping from Coarse to Fine whith the canopy model being activated.
Since Canopy run was introduced, this parameter is to be depreciated.
htop - top boundary minimum height
Defines the minimal height that should be considered to evaluate the elevation of the top boundary condition.
htop=-1
; top boundary minimum height [m]
; float > 0. ; if < 0: automatic evaluation
; validity: 200. ≤ diavisu ≤ 100000.
; default: -1
Automatic evaluation
htop is evaluated from orography data, using: htop = 6 * (Zmax - Zmin)
Zmin and Zmax are the minimal and maximal ground elevations.
Info
The constant elevation used for defining the top boundary condition is then evaluated using:
Ztop = Zmin + htop
hturb - turbine zone height
Defines the height of the wind turbine refinement zone.
Info
The vertical size of the cells generated in the wind turbine zone is controlled using the turbine zone maximal vertical resolution.
hcanop - canopy zone height
Defines the height of the canopy refinement zone.
Info
The vertical size of the cells generated in the canopy zone is controlled using the canopy zone maximal vertical resolution.
Automatic Evaluation
hcanop is evaluated from roughness data, using: htop = max(10., 30 * zmax_rou)
zmax_rou is the maximal ground roughness length.
dzmin_coarse - coarse mesh minimal vertical resolution
Defines the height of the first layer of cells above the Coarse mesh version ground boundary.
dzmin_coarse=2.
; coarse mesh minimal vertical resolution [m]
; float
; validity: 0.01. ≤ dzmin_coarse ≤ 5.
; default: 2.
dzmin_fine - fine mesh minimal vertical resolution
Defines the height of the first layer of cells above the Fine mesh version ground boundary.
dzmin_fine=1.
; fine mesh minimal vertical resolution [m]
; float
; validity: 0.01. ≤ dzmin_coarse ≤ 2.
; default: 1.
dzcanop_coarse - coarse mesh canopy zone maximal vertical resolution
Defines the upper limit of the vertical size of the cells in the canopy zone of the Coarse mesh version.
dzcanop_coarse=4.
; coarse mesh canopy zone maximal vertical resolution [m]
; float
; validity: 2. ≤ dzcanop_coarse ≤ 10.
; default: 4.
dzcanop_fine - fine mesh canopy zone maximal vertical resolution
Defines the upper limit of the vertical size of the cells in the canopy zone of the Fine mesh version.
dzcanop_fine=2.
; coarse mesh canopy zone maximal vertical resolution [m]
; float
; validity: 2. ≤ dzcanop_coarse ≤ 5.
; default: 4.
dzturb_coarse - coarse mesh turbine zone maximal vertical resolution
Defines the upper limit of the vertical size of the cells in the turbine zone of the Coarse mesh version.
dzturb_coarse=10.
; coarse mesh turbine zone maximal vertical resolution [m]
; float
; validity: 5. ≤ dzturb_coarse ≤ 40.
; default: 10.
dzturb_fine - fine mesh turbine zone maximal vertical resolution
Defines the upper limit of the vertical size of the cells in the turbine zone of the Fine mesh version.
dzturb_fine=5.
; coarse mesh turbine zone maximal vertical resolution [m]
; float
; validity: 5. ≤ dzturb_coarse ≤ 20.
; default: 5.
dztop_coarse - coarse mesh maximal vertical resolution
Defines the upper limit of the vertical size of the cells for the Coarse mesh version.
dztop_coarse=2000.
; coarse mesh maximal vertical resolution [m]
; float
; validity: 100. ≤ dztop_coarse ≤ 2000.
; default: 2000.
dztop_fine - fine mesh maximal vertical resolution
Defines the upper limit of the vertical size of the cells for the Fine mesh version.
dztop_fine=1000.
; fine mesh maximal vertical resolution [m]
; float
; validity: 100. ≤ dztop_fine ≤ 1000.
; default: 1000.
expcanop_coarse - coarse mesh canopy zone expansion coefficient
Defines the expansion coefficient in the canopy zone of the Coarse mesh version.
expcanop_coarse=1.15
; coarse mesh canopy zone expansion coefficient [-]
; float
; validity: 1. ≤ expcanop_coarse ≤ 1.5
; default entry: 1.15
expcanop_fine - fine mesh canopy zone expansion coefficient
Defines the expansion coefficient in the canopy zone of the Fine mesh version.
expcanop_fine=1.1
; fine mesh canopy zone expansion coefficient [-]
; float
; validity: 1. ≤ expcanop_fine ≤ 1.5
; default: 1.1
expturb_coarse - coarse mesh turbine zone expansion coefficient
Defines the expansion coefficient in the turbine zone of the Coarse mesh version.
expturb_coarse=1.15
; coarse mesh turbine zone expansion coefficient [-]
; float
; validity: 1. ≤ expturb_coarse ≤ 1.5
; default: 1.15
expturb_fine - fine mesh turbine zone expansion coefficient
Defines the expansion coefficient in the turbine zone of the Fine mesh version.
expturb_fine=1.1
; fine mesh turbine zone expansion coefficient [-]
; float
; validity: 1. ≤ expturb_fine ≤ 1.5
; default: 1.1
exptop_coarse - coarse mesh top zone expansion coefficient
Defines the expansion coefficient in the top zone of the Coarse mesh version.
exptop_coarse=1.2
; coarse mesh top zone expansion coefficient [-]
; float
; validity: 1. ≤ exptop_coarse ≤ 1.5
; default: 1.2
exptop_fine - fine mesh top zone expansion coefficient
Defines the expansion coefficient in the top zone of the Fine mesh version.
exptop_fine=1.15
; fine mesh top zone expansion coefficient [-]
; float
; validity condition: 1. ≤ exptop_fine ≤ 1.5
; default entry: 1.15
nsmoo - number of smoothing loops
Defines the number of smoothing loops for the ground mesh.
Which effects?
The higher nsmoo will be, the stronger will be the applied smoothing.
smoocoef - smoothing coefficient
Defines how strong will be the smoothing in each of the smoothing loop.
Which effects?
The higher smoocoef will be, the stronger will be the applied smoothing.
insmoo - inlet smoothing method
Defines the smoothing method near site boundaries of the domain.
insmoo=extra
; inlet smoothing method [-]
; string
; validity: in [flat, without, extra]
; default: extra
Info
insmoo=without ⇒ no specific smoothing is applied
insmoo=extra ⇒ the terrain near the side boundaries is smoothed
insmoo=flat ⇒ the terrain near the side boundaries is smoothed toward a flat terrain
Which effects?
roudist - no canopy boundary ring length
Defines the size of the boundary ring in which the canopy modelling is not activated.
roudist=-1.
; no canopy boundary ring length [m]
; float > 0. ; if < 0: automatic evaluation
; validity: 0. <= roudist <= 100000.
; default: -1.
Automatic evaluation
roudist is evaluated using expression: roudist = diaref / 2. + 1000.
roulim - roughness length limit
Defines the roughness length limit below which the canopy modelling is not activated.
roufact - roughness length ratio
Defines the roughness length ratio used to evaluate the canopy height.
Info
Canopy height is evaluated using expression: Hcano = roufact * r
where r is the roughness length given to the ground cell.