Field data#

Field data is an attribute of a session and thus an object. With PyFluent, you can access Fluent surface, scalar, and vector field data.

Multiple fields in a request#

You can get data for multiple fields in a single request and see the data for all of these fields in a single response.

Request

The add_get_<items>_request methods combine requests for multiple fields in a single request:

  • add_get_surfaces_request adds a surfaces request.

  • add_get_scalar_fields_request adds a scalar fields request.

  • add_get_vector_fields_request adds a vector fields request.

Response The get_fields method returns all requested fields in a single response. It provides a dictionary containing the requested fields as a numpy array in the following order:

tag_id [int]-> surface_id [int] -> field_name [str] -> field_data[np.array]

Tag ID#

A tag ID is generated by applying `bitwise or` on all tags for a request. Here is a list of supported tags and their values:

  • OVERSET_MESH: 1,

  • ELEMENT_LOCATION: 2,

  • NODE_LOCATION: 4,

  • BOUNDARY_VALUES: 8,

For example, if you request the scalar field data for element location[2], in the dictionary, tag_id is 2. Similarly, if you request the boundary values[8] for node location[4], tag_id is (4|8), or 12.

Surface ID#

The surface ID is the same one that is passed in the request.

Field name#

A request returns multiple fields. The number of fields depends on the request type.

Surface request#

The response to a surface request contains any of the following fields, depending on the request arguments:

  • faces, which contain face connectivity

  • vertices, which contain node coordinates

  • centroid, which contains face centroids

  • face-normal, which contains face normals

Scalar field request#

The response to a scalar field request contains a single field with the same name as the scalar field name passed in the request.

Vector field request#

The response to a vector field request contains two fields:

  • vector field, with the same name as the vector field name that is passed in the request

  • vector-scale, a float value indicating the vector scale.

Example#

#Get field data
field_data = session.field_data

#Add requests

#Data for surfaces for following requests will be returned in tag_id 0. As there is no tag.

field_data.add_get_surfaces_request(surface_ids=[1], provide_vertices=True,
                                    provide_faces=False, provide_faces_centroid=True
                                   )

field_data.add_get_surfaces_request(surface_ids=[2], provide_vertices=True,
                                   provide_faces=True
                                   )

#Data for tempaeraure for following request will be returned in tag_id 12 i.e. 4|8.
field_data.add_get_scalar_fields_request(surface_ids=[1,2], field_name="temperature",
                                        node_value=True, boundary_value=True
                                        )

#Data for tempaeraure for following request will be returned in tag_id 4.
field_data.add_get_scalar_fields_request(surface_ids=[3], field_name="temperature",
                                         node_value=True, boundary_value=False
                                         )

#Data for pressure for following request will be returned in tag_id 2.
field_data.add_get_scalar_fields_request(surface_ids=[1,4], field_name="pressure",
                                        node_value=False, boundary_value=False
                                        )

#Get fields

payload_data = field_data.get_fields()


#Data will be returned in dictionary with order
#`tag_id [int]-> surface_id [int] -> field_name [str] -> field_data [np.array]`
{
  0:{
     1:{
       "vertices": np.array #for vertices.
       "centroid": np.array #for faces centroid.
       },
     2:{
       "vertices": np.array #for vertices.
       "faces": np.array #for faces connectivity.
       },
    },
  12:{
     1:{
       "temperature": np.array #for temperature at node location with boundary values.
       },
     2:{
       "temperature": np.array #for temperature at node location with boundary values.
       },
    },
  4:{
     3:{
       "temperature": np.array #for temperature at node location.
       }
    },
  2:{
     1:{
       "pressure": np.array #for pressure at element location.
       },
     4:{
       "pressure": np.array #for pressure at element location.
       },
    },
}

One field per request#

You can receive one field for each request. There is a separate method for each type of field (surface, scalar, or vector):

  • get_surface_data gets surface data.

  • get_scalar_field_data gets scalar field data.

  • get_vector_field_data gets vector field data.

For a surface or scalar field request, the response contains a dictionary of surface IDs and a numpy array of the requested field.

surface_id [int] -> field[np.array]

For a vector field request, the response is a dictionary of surface IDs and a tuple of a numpy array of vector field and vector-scale.

surface_id [int] -> (vector field [np.array],  vector-scale [float])

Note

In Fluent, you can associate a surface name with multiple surface IDs. Thus, a response can contain a surface ID as a key of the returned dictionary.

Example#

from ansys.fluent.core.services.field_data import SurfaceDataType

#Get field data object
field_data = session.field_data

#wall surface is associated with two IDs i.e. id1 and id2

#Get surface data
vertices = field_data.get_surface_data("wall", SurfaceDataType.Vertices)
#return value>> {id1: np.array, id2: np.array}
normals = field_data.get_surface_data("wall", SurfaceDataType.FacesNormal)
#return value>> {id1: np.array, id2: np.array}

#Get scalar field data
scalar_field_data = field_data.get_scalar_field_data("wall", "temperature")
#return value>> {id1: np.array, id2: np.array}

#Get vector field data
vector_field_data = field_data.get_vector_field_data("wall", "velocity")
#return value>> {id1: (np.array, float), id2: (np.array, float)}
FieldData.add_get_surfaces_request(surface_ids, overset_mesh=False, provide_vertices=True, provide_faces=True, provide_faces_centroid=False, provide_faces_normal=False)#

Add request to get surface data (vertices, face connectivity, centroids, and normals).

Parameters
surface_idsList[int]

List of surface IDS for the surface data.

overset_meshbool, optional

Whether to get the overset met. The default is False.

provide_verticesbool, optional

Whether to get node coordinates. The default is True.

provide_facesbool, optional

Whether to get face connectivity. The default is True.

provide_faces_centroidbool, optional

Whether to get face centroids. The default is False.

provide_faces_normalbool, optional

Whether to get faces normal. The default is False

Returns
None
Return type

None

FieldData.add_get_scalar_fields_request(surface_ids, field_name, node_value=True, boundary_value=False)#

Add request to get scalar field data on surfaces.

Parameters
surface_idsList[int]

List of surface IDs for scalar field data.

field_namestr

Name of the scalar field.

node_valuebool, optional

Whether to provide the nodal location. The default is True. If False, the element location is provided.

boundary_valuebool, optional

Whether to provide the slip velocity at the wall boundaries. The default is False. When True, no slip velocity is provided.

Returns
None
Return type

None

FieldData.add_get_vector_fields_request(surface_ids, vector_field='velocity')#

Add request to get vector field data on surfaces.

Parameters
surface_idsList[int]

List of surface IDs for vector field data.

vector_fieldstr, optional

Name of the vector field.

Returns
None
Return type

None

FieldData.get_fields()#

Get data for previously added requests.

Returns
Dict[int, Dict[int, Dict[str, np.array]]]

Data is returned as dictionary of dictionaries in following structure: tag_id [int]-> surface_id [int] -> field_name [str] -> field_data[np.array]

Return type

Dict[int, Dict[int, Dict[str, array]]]

FieldData.get_surface_data(surface_name, data_type, overset_mesh=False)#

Get surface data (vertices, faces connectivity, centroids, and normals).

Parameters
surface_namestr

Surface name for the surface data.

data_typeSurfaceDataType

SurfaceDataType Enum member.

overset_meshbool, optional

Whether to provide the overset method. The default is False.

Returns
Dict[int, np.array]

Dictionary containing a map of surface IDs to surface data.

Return type

Dict[int, array]

FieldData.get_scalar_field_data(surface_name, field_name, node_value=True, boundary_value=False)#

Get scalar field data on a surface.

Parameters
surface_namestr

Name of the surface.

field_namestr

Name of the scalar field.

node_valuebool, optional

Whether to provide data for the nodal location. The default is True. When False, data is provided for the element location.

boundary_valuebool, optional

Whether to provide slip velocity at the wall boundaries. The default is False. When True, no slip velocity is provided.

Returns
Dict[int, np.array]

Dictionary containing a map of surface IDs to the scalar field.

Return type

Dict[int, array]

FieldData.get_vector_field_data(surface_name, vector_field='velocity')#

Get vector field data on a surface.

Parameters
surface_namestr

Name of the surface.

vector_fieldstr, optional

Name of the vector field.

Returns
Dict[int, Tuple[np.array, float]]

Dictionary containing a map of surface IDs to a tuple of vector field and vector scale.

Return type

Dict[int, Tuple[array, float]]