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Common Fluids Format 2024 R2

Ansys Common Fluids Data Models

Last update: 16.07.2025

Project Data Model

The Project data model allows relationships between data models to be expressed. It may also be used to express sequences of run outputs which might typically be seen for transient runs and parametric studies.

Project models may refer to multiple CFF Restart Data Model and CFF Post Data Model models.

See Project API for further details.

CFF Restart Data Model

The Common Fluids Format API depends on data being stored within a number of different files that contain data models that represent the Mesh, Topology, Physics, and Solution data.

Mesh Requirements

Mesh should only be defined using the Cell/Node Definition (where cells are defined by a sequence of nodes) or the Face/Node Definition (where faces are defined by nodes and the faces have cell parents).

Note
If your model contains Polyhedral cells, you should use the Poly/Face Definition. In other cases, the Face/Node Definition should always be used.

Topology Requirements

It is recommended to supply a Topology Model. For Mesh-only files this data can be omitted.

The Topology provides a valuable connection between the data within the Physics Model and the Mesh Model.

In the case of Ansys Fluent, this data is not yet written but can be built using the ansys::LocationModelBuilder utility.

Physics Requirements

Physics should be provided when appropriate. For Mesh-only files this data can be ommitted.

Project Data

The associations between models in a fluid simulation may be represented in a Project.

CFF Post Data Model

The CFF Post Data Model provides a very simplified model when compared to the CFF Restart Data Model. The Mesh will only contain simple Zones that represent regions of mesh intended for fast Post-processing purposes. Topology and Physics should not be written. Solution data should be provided when required for Post-processing.

Mesh Requirements

Mesh data must always be provided in a Cell/Node Definition for all Cells other than polyhedral cells. Polyhedral cells or zones that contain polyhedral cells should always be specified using a Poly/Face Definition.

Note
Each Face Zone and each Cell Zone will refer to a Node Zone that is unique, that is, all Face Zones and Cell Zones are always disconnected.

Topology Requirements

Topology should not be provided by a CFF Post Data Model.

Physics Requirements

Physics should not be provided by a CFF Post Data Model.

Solution Model Requirements

Solution data is always stored on node locations. The values should require no further manipulation in order for you to accruately process the data within your application or a post-processor (for example, Ansys EnSight or Ansys CFD-Post).

Note
Each face and cell zone may contain solution values that correspond to the distinct nodes against which the face and cell zones are defined. Although this implies data may be duplicated, it means that data can be accessed more quickly and with less memory overhead, as is required for data access on a subset of the Zones.

Project Data

The associations between models in a fluid simulation may be represented in a Project.

Data Models

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