Core ConceptsΒΆ

This section introduces the main building blocks of pyOFTools and how they work together to enable flexible, modular post-processing of OpenFOAM simulation data. The diagram below illustrates the typical workflow: data is wrapped, manipulated by nodes, and exported for further analysis.

        graph LR
        subgraph "Initial Data"
                InternalDataSet[InternalDataSet]
        end
        subgraph "Nodes"
                Directional[Directional]
                VolIntegrate[VolIntegrate]
        end
        subgraph "Writer"
                CSVWriter[CSVWriter]
        end

        InternalDataSet --> Directional
        Directional --> VolIntegrate
        VolIntegrate --> CSVWriter

Diagram Explanation

This diagram shows the general workflow in pyOFTools:

  • Data from OpenFOAM is wrapped in an InternalDataSet (initial data).

  • The data is then manipulated by a series of nodes (such as Directional for binning and VolIntegrate for aggregation).

  • Finally, the processed results are written out using a writer (e.g., CSVWriter).

This modular approach allows you to flexibly transform and analyze simulation data before exporting it for further use.

General Workflow Example

from pybFoam import volScalarField
from pyOFTools.datasets import InternalDataSet
from pyOFTools.geometry import FvMeshInternalAdapter
from pyOFTools.writer import CSVWriter
from pyOFTools.aggregators import VolIntegrate
from pyOFTools.binning import Directional
from pyOFTools.workflow import WorkFlow

# Wrap OpenFOAM field and mesh
alpha = volScalarField.from_registry(mesh, "alpha.water")
dataset = InternalDataSet(
         name="alpha_water",
         field=alpha["internalField"],
         geometry=FvMeshInternalAdapter(mesh),
)

# Build workflow: bin and integrate
workflow = WorkFlow(initial_dataset=dataset)
workflow = workflow.then(Directional(bins=[0, 0.1, 0.2], direction=(1,0,0), origin=(0,0,0)))
workflow = workflow.then(VolIntegrate())

# Export results
writer = CSVWriter(file_path="postProcessing/alpha_bins.csv")
writer.create_file()
writer.write_data(time=mesh.time().value(), workflow=workflow)

workflow: Chains nodes to process the data step-by-step.

It transforms the initial dataset through a series of operations, ultimately producing the desired output.

DataSet Classes

pyOFTools provides several DataSet classes to represent different types of OpenFOAM data:

  • InternalDataSet: Represents internal field data (e.g., cell-centered values) and mesh geometry. Used for most volume-based analyses.

  • PatchDataSet: Handles data on boundary patches, such as wall or inlet/outlet fields.

  • SurfaceDataSet: For surface field data, useful in cases with surface meshes or sampled surfaces.

name: str
field: FieldType
geometry: GeometricalInformation # surfaceMesh, volMesh
mask: Optional[boolList] = None
groups: Optional[labelList] = None

  • AggregatedDataSet: Stores results of aggregation operations (e.g., integrated values, statistics) and considers the group and mask information.

Each DataSet class provides methods for accessing, filtering, and manipulating simulation data, making it easy to build flexible post-processing workflows.

Nodes Nodes are modular operations that transform DataSets. For example, the Directional node segments data into bins along a specified direction (width or height), while VolIntegrate aggregates data by integrating over the mesh. Nodes are chained together to build a workflow.

Writer Writers save the workflow results to files. The CSVWriter class exports processed results to CSV files. Each workflow writes its output (e.g., volume, mass distribution) to a separate file, making results easy to visualize and share.