# 7. ESonix Run Parameters¶

## 7.1. Regular Runs¶

The Regular Run Parameters are defined in three different places:

- In the project settings (cf. Creating a project).
- In the new run form (cf. Regular runs).
- In a batch command file (
*cf*. Batch Analysis).

The screen shots shown hereunder are visible from the “new project ” form, but the “new run” forms are almost the same.

The parameters shown by default in the new run form inherit from the one defined in the project form.

### Model Parameters¶

#### Units¶

`units`

: Set of units in which the model and analysis results are given. SI (modified with bar instead of Pa) or Imperial.

Batch Equivalence: `unit_im`

`unit_im`

accepts a boolean (True or False) value.

specify True for an imperial units model:

```
unit_im = True
```

or False for a SI (bar instead of Pa) model:

```
unit_im = False
```

#### Doors Position¶

`doors position`

: Set the initial position (configuration) of the- door to be used in the analysis.

Batch Equivalence: `doors`

`doors`

accepts one of the strings: `"open"`

, `"close"`

or `"both"`

.

Example:

```
doors = "close" # to run only closed doors aircraft configuration
```

#### Load Cases to run¶

`load cases to run`

: Comma separated list of load cases ID to run. This is useful to restrict calculations to a single or a subset of load cases as defined in the model spreadsheet. If blank, all load cases will be considered in the run.

Batch Equivalence: `lcs`

`lcs`

accepts:

- empty (
`lcs =`

)- None (
`lcs = None`

)- a valid python list of integers (
`lcs = [1, 3, 5]`

)

Example:

```
lcs = None # Run all the load cases
```

or:

```
lcs = [1, 5, 3] # Run load cases 1, 3 and 5
```

#### Sub-modelling Zone¶

`sub-modelling zone`

: Set specific part of the model to be run. This is useful to restrict calculations to a single or a subset of model as defined in the model spreadsheet. If blank, the full model will be run.

Batch Equivalence: `submodel`

`submodel`

needs and integer (default to 0). If set to 0, then
the whole model is analized. If set to 1, only the first neighbors zone. If set to 2, two rows of neighbours are accounted, *etc*.

Example:

```
submodel = 0 # Run the whole model
```

or:

```
submodel = 1 # Run the first "row" of neighbors.
```

### Runtime Parameters¶

#### Engine¶

`engine`

: Thermodynamical engine to use

Batch Equivalence: `engine`

`engine`

accepts one of the following strings:

`"isentropic"`

: equivalent to the “isentropic” selection in the combo box.`"isentropic_cddyn"`

: equivalent to the “isentropic + dynamical CD” selection in the combo box.`"polytropic"`

: equivalent to the “polytropic” selection in the combo box.`"polytropic_cddyn"`

: equivalent to the “polytropic + dynamical CD” selection in the combo box.

Example:

```
engine = "isentropic_cddyn" # "isentropic + dynamical CD" engine
```

#### Timestep¶

`timestep`

: Simulation time increment.

Batch Equivalence: `timestep`

`timestep`

accepts a float defining the time step to use.

Example:

```
timestep = 1e-5 # Time step = 0.00001
```

#### Sampling¶

`sampling`

: Data sampling for disk storage.

Batch Equivalence: `sampling`

`sampling`

accepts a float defining the sampling to use.

Example:

```
sampling = 1e-4 # sampling = 0.0001
```

#### Write Data on Event¶

`Write data on event`

: When set to True, runtime records are written when an event occur. Should be let to True except to check compatibility with V2 results.

Batch Equivalence: `write_on_event`

`write_on_event`

accepts a boolean value (`True`

or `False`

)

Example:

```
write_on_event = True
```

#### timeout¶

`timeout`

: Simulation maximum time. If no other convergence criteria is met before, timeout stop the run.

Batch Equivalence: `timeout`

`timeout`

accepts a float defining the simulation timeout.

Example:

```
# Simulation will stop after 1.4s if no convergence is found:
timeout = 1.4
```

#### convergence criteria¶

`convergence criteria`

: How to calculate convergence. This is a low-influence parameter as most of the time, `timeout`

will end the calculation before the real convergence is reached.

As for now, three convergence criteria exist:

- “
`H`

”: simulation stops once all differential pressure decrease.- “
`first_conv`

”: simulation stops once one volume reach ambient pressure.- “
`timeout`

”: simulation stops at timeout.

Batch Equivalence: `convergence_criteria`

`convergence_criteria`

accepts one of “`H`

”, “`fisrt_conv`

” or “`timeout`

” strings.

Example:

```
# Simulation will stop once all differential pressure decrease or after timeout no convergence is found:
convergence_criteria = "H"
```

#### Post-Convergence margin¶

`post-convergence margin`

: Margin (in nb of steps) after convergence is- reached before stopping calculation.

Batch Equivalence: `pct_margin`

`pct_margin`

accepts a float.

Example:

```
# simulation will run additional 5% of elapsed time
# once convergence is met:
pct_margin = 5
```

### Runtime Advanced Parameters¶

#### adaptive strategy¶

`adaptive strategy`

: Adaptive strategy to adopt for the run. The adaptive strategy is based on the courant number analysis. The proposed strategies are:- “
**no adaptive timestep**”: legacy behavior, timestep is constant during the run. - “
**Courant Number flow control, no adaptive sampling**”: Time step is dynamically adjusted during the run to match the`adaptive strategy Max Co target`

. Sampling is as defined un`Runtime`

tab. - “
**Courant Number flow control, time step on sampling cst ratio**”: Time step is dynamically adjusted during the run to match the`adaptive strategy Max Co target`

. Sampling is adjusted to keep constant the \({time\ step} / sampling\) ratio.

- “

Batch Equivalence: `adaptive`

`adaptive`

accepts an integer as per:

`0`

: equivalent to “no adaptive timestep”`1`

: equivalent to “Courant Number flow control, no adaptive sampling”`2`

: equivalent to “Courant Number flow control, time step on sampling cst ratio”

Example:

```
# adaptive time step, keeping initial timestep/sampling ratio:
adaptive = 2
```

#### adaptive strategy max co target¶

`adaptive strategy max co target`

: Maximum Courant number allowed for an adaptive run. Defaulted to 1E-4. This target may be decreased for simple analysis. Decreasing the Courant Number target leads to more accurate yet more expensive runs.

Batch Equivalence: `adaptive_maxco`

`adaptive_maxco`

accepts a float.

Example:

```
# adaptive max CO Target is set to 1e-5
adaptive_maxco = 1e-5
```

#### adaptive strategy neighborhood zone¶

`adaptive strategy neighborhood zone`

: Defines the neighborhood zone where Courant Number Criteria is checked. The greater this number, the more accurate yet expansive the calculation is. More details here.

Batch Equivalence: `adaptive_zone`

`adaptive_zone`

accepts an integer.

Example:

```
# Check Courant number for one zone around the exploded volume
adaptive_zone = 1
```

#### adaptive strategy max co ramp¶

`adaptive strategy max co ramp`

: Defines how fast ESonix will reach the Courant Number Target. Use it for debugging only, as an incorrect number could lead to unstable results.

Batch Equivalence: `adaptive_ramp`

`adaptive_ramp`

accepts a float<1.

Example:

```
adaptive_ramp = 0.1
```

#### default opening latency¶

`default opening latency`

: Set a default latency for all opening feature.

Batch Equivalence: `set_default_latency`

`set_default_latency`

accepts a float.

Example:

```
# set all the items to wait for 0.01sec before opening
set_default_latency = 0.01
```

#### raw merging¶

`raw merging`

: Defaulted to False. When set to True (not advised), use the legacy behavior (V1) for merged load cases post-processing.

Batch Equivalence: `raw_merging`

`raw_merging`

accepts a boolean value (`True`

or `False`

).

Example:

```
raw_merging = False
```

## 7.2. Combination Runs¶

### Reference Node & “Nodes to combine”¶

`Reference Node`

: Base node for combination. This node will keep it sown load cases
numbering as it.

`Nodes to combine`

: Selectable list of nodes to combine to `Reference Node`

. If
some of their load cases ID are common, the load-cases are mapped to available IDs.

Batch Equivalence: `nodes`

`nodes`

accepts a list of nodes to combine. The first node of the series will become the “reference node”.
The `nodes`

parameter therefore combine “Reference Node” and “Nodes to combine” into a single parameter.

Example:

```
# node A4 is the reference; A2 and A5 are combined with
nodes = [4, 2, 5]
```

## 7.3. Sensitivity Runs¶

`Sensitivity`

: build a single set of results comparing results between existing nodes or between nodes (“reference” and/or “nodes to combine”) and a external file.

### “Reference Node” & “Nodes to combine”¶

`Reference Node`

: Base node for sensitivity. This will be the first one on the bar plots.

`Nodes to combine`

: Selectable list of nodes to compare.

Batch Equivalence: `nodes`

`nodes`

accepts a list of nodes to compare. The first node of the series will become the “reference node”.
The `nodes`

parameter therefore compare “Reference Node” and “Nodes to combine” into a single parameter.

Example:

```
# node A1 is the reference; A2 and A4 are compared with
nodes = [1, 2, 4]
```

### “External reference file”¶

Batch Equivalence: `external_reference`

`external_reference`

accepts the external file name. The sensitivity will then compare the pre-defined `nodes`

with the `external_reference file`

into a single parameter.

Example:

```
external_reference = "External_data.xlsx"
```

## 7.4. To go deeper¶

- For adaptive strategies: check Adaptive Runtime parameters.
- For more information about merged load cases, refer to Merged Load Cases.