Ansys Common Fluids Data Models
Last update: 16.07.2025Project 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 stufies.
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 you model contains Polyhedral cells, you should use the Poly/Face Definition. Instead the Face/Node Definition should always be used.
Topology Requirements
It is recommended that a Topology Model is supplied. For Mesh only files this data can be ommitted.
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 nto 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 i.e. 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 Requirememts
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 (e.g. 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 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.