FineGrid parameter (dialog)
The finegrid subdivides the model into small cells which are then used to
solve the thermal equations during simulation. Creation of the finegrid is
controlled via finegrid parameters. Values offered by default have been preset
in such manner, that for most usual cases none of them needs to be adjusted.
Settings of the finegrid process directly influence the size of the equitation
system to be solved  the more detailed fine grid will create larger, eventually
more complex, system of equations with higher number of cells to be balanced  that number is shown within the
headings of evaluation reports.
Important: Very fine and detailed gridding (discretization)
does not automatically ensure higher precision of results. Too detailed
discretization might lead to unnecessary and inefficiently long calculations or
even to results with less precision.
The most important setting of Start Step
shall typically correspond to the thickness of thinnest thermally significant
structure of the construction. As such higher subdivision of metal slabs is not
advisable.
The Maximum Step shall be significantly
raised when models of large dimensions of homogenous structures are considered.
The setting of Target Model Size
is mostly used while benchmarking the precision of results, typically as last
step during expertise process:

coupling coefficients and
the number of cells of a
calculation shall be identified
within its
Coupling Coefficients report,
 for the purpose of
additional calculation of
results the
Target Model Size will be
requested at the half or at the
double of the cell count
reported earlier and the new
calculation is executed,

Coupling coefficients
resulting from that second
calculation (with half or double
number of cells) are compared to
the values received with the
first calculation and respective
precision criteria is validated
then.
This final process of validation the precision of results conforms to the
requirements set by the Standard EN ISO 10211.
Important: This validation is independent from the check of
results precision provided within the respective
section of the Coupling Coefficients report (the
relative CloseUp Error).
Start Fine Grid at: 
These are parameters defining starting criteria of the
rasterizing process (creation of the fine grid) 
Space Surfaces 
Rasterizing will be initiated with its
start step at each space surface and
continue towards interior of the construction. 
Adiabatic CutOff Planes 
Rasterizing will be initiated with its
start step at each adiabatic cutoff plane
(adiabatic boundary) and continue towards interior of the
construction.
(in earlier application versions also called "CutOff/Wonder" foil) 
Power Source Boundaries 
Rasterizing will be initiated with its
start step at each boundary line of any
power source. 
Material Changes 
Rasterizing will be initiated with its
start step at boundary lines of different
materials. An additional start criteria is defined the
quotient of conductivity values (lambda quotient). 
when λ, μ, ρ·c ratio above 
Rasterizing will start with its
start step at boundary lines of
different materials (material change) if the ratio of conductivity
values (λ, μ, ρ·c values) of these materials is larger than the
magnitude entered here.
If the change of λ, μ and ρ·c is not significant (quotient is smaller the the
value entered here) rasterizing will continue with its normal coarsening
process.
Remark: To force the rasterizing to start at each material change
boundary set this parameter <=1
Remark: The ratio (quotient) of conductivities of two materials is
always calculated as the division of the larger value by the smaller one,
thus it always results in ratios values >= 1. 
Step by: 
Start Step 
Rasterizing will start with this distance when
starting criteria is matched at
specific position.
Remark: This is not the smallest step within the resulting fine grid
 smaller structures can result relative position of elements and element
dimensions also! 
Max Step 
The process of coarsening
the fine grid away from
start positions does not go beyond this value. If applicable rasterizing
will continue with this maximum value
Remark: This value can be estimated automatically if
target model size (number of fine
grid cells) is chosen. 
Step Growth Factor 
At each further rasterizing step away from the position
where the
starting criteria has been matched
the step of fine grid (distance) is enlarged by that factor.
Remark: ≥ 1.0 

Suppress fine grid in direction of X/Y/Z axis 
Suppresses the process of fine grid generation in that
specific axis direction. Resulting fine grid is then identical to minimal
model grid.
Remark: The application automatically detects homogenous dimension of
the model (in that direction there will be no heat flow nor temperature
gradients). If such direction is identified already within minimum grid,
fine grid generation in this direction is automatically suppressed
(regardless of the setting of the respective parameter here). 
Target Model Size: 
Target for Model Size 
When checked, one can request the target number of
equations (cells). Rasterizer will then vary the
maximum step to match the size at its best 
# Cells 
Rasterizer will vary the
maximum step by an iterative search
until it reaches the number fine grid cells within +/ 10% estimation range.
Remark: If the target number cannot be reached sufficiently (i.e.
maximum step could not be found
satisfying other criteria), try to change the
coarsening factor (step growth factor).
Remark: „Max Step“ will be varied between „Start Step“ and full model
extent. If there is no solution sufficiently matching the targeted criteria
the most coarse fine grid (in the case the target number was too small) or
the finest fine grid (if the target was too large) will be created. 

Restore Default

Reset all rasterizer settings to
values provided in the application settings 
Set As Default

Current project setting will replace
values provided in the application settings. 
Pick from Project...

Fine Grid settings will be loaded from another project. 
Always show this dialog automatically when required 
If checked the application will automatically reveal this
dialog on each rasterizer run (in preparation of each calculation). 
Fine Grid parameters are saved to the
project file.
At first the application creates a "minimal grid" resulting from the
overlapping of all elements. Overlapping of elements might result in removal of
some elements if those are completely overlapped. The resulting model can be
observed within the Elements3D window. The
ModellingReport will list all
spaces, surfaces, power sources and materials actually used within final model.
Then, the
application "visits" all boundaries of the minimal grid (which represents
elements entered) and identifies if they are one of:
 Space surface (space boundary)
 change of material
 power source boundary
 adiabatic boundary
Having
finegrid parameters set, the application will start adding additional grid
planes in both directions away from these boundaries:
 initially with starting step
 every next one in the distance enlarged by the step growth
factor compared to the previous
 until the maximum step size has been reached, which will be
used to subdivide the rest of the model.
This
process is executed in all three Cartesian dimensions if not suppressed.
See also: Solver,
Application settings,
Rasterizing
