User guide

Anyone who wants to use PyFluent can import its Python modules and develop Python code to control and monitor Ansys Fluent.

Overview

You use the launch_fluent() method to launch an instance of Fluent that runs as a server in the background.

You can launch Fluent in solution mode with no arguments:

from ansys.fluent.core import launch_fluent

solver_session = launch_fluent(mode="solver")

You can launch Fluent in meshing mode with:

from ansys.fluent.core import launch_fluent

meshing_session = launch_fluent(mode="meshing")

For more information, see Launching Fluent locally and Launching Fluent.

You can use PyFluent to create and initialize multiple, independent session objects. Each session object provides full access to the Fluent components relevant to the session’s current mode (solution or meshing).

Solution mode session

A solution mode session has an active solver object that provides two distinct interfaces to the solver:

• tui object

• root object

For general guidance on using these two objects, see Specifying solver settings.

Solver tui object

The solver tui object is a complete Python exposure of the Fluent solver TUI (text user interface). This object allows straightforward execution of solver commands and modification of solve settings in a manner that is familiar to existing Fluent users:

tui = solver_session.tui

tui.file.read_case("pipe.cas.h5")

tui.define.models.energy("yes")

For the full hierarchy under the solver tui object, see Solver TUI commands. For general guidance on using TUI commands, see Using TUI commands.

Solver root object

The solver root object exposes most of the solver capabilities covered by the solver tui object and provides significant additional interface features that are not possible via the tui object:

root = solver_session

root.file.read(file_type="case", file_name="pipe.cas.h5")

root.setup.models.energy.enabled = True

energy_is_enabled = root.setup.models.energy.enabled()

For the full hierarchy under the solver root object, see solver.tui. For additional interface features, see Settings objects.

Meshing mode session

A meshing mode session has an active meshing object that provides two distinct interfaces to the mesher:

• tui object

• meshing workflow, which consists of meshing and workflow properties and the PartManagement and PMFileMangement classes

Meshing tui object

The meshing tui object is a complete Python exposure of the Fluent meshing TUI (text user interface). This object allows straightforward execution of meshing commands and modification of meshing settings in a manner that is familiar to existing Fluent users:

tui = meshing_session.tui

tui.mesh.prepare_for_solve("yes")

tui.file.write_case("pipe.cas.h5")

For the full hierarchy under the meshing tui object, see meshing.tui. For general guidance on using TUI commands, see Using TUI commands.

Meshing and Workflow properties

The meshing object has meshing and workflow properties that together provide access to Fluent’s meshing workflows. This interface is consistent with the Python meshing workflow interface that Fluent meshing exposes directly:

workflow = meshing_session.workflow

workflow.InitializeWorkflow(WorkflowType="Watertight Geometry")

import_geometry = workflow.TaskObject["Import Geometry"]

import_geometry.Arguments = {"FileName":"pipe.scdoc.pmdb"}

import_geometry.Execute()

meshing = meshing_session.meshing

meshing.GlobalSettings.LengthUnit.setState("mm")

For additional examples, see Using meshing workflows. For information on the full interface, see meshing.datamodel.

Session object

In either a solution or meshing mode session, the session object provides a more direct interaction via its scheme_eval attribute:

unsteady = solver_session.scheme_eval.scheme_eval("(rp-unsteady?)")

The argument to scheme_eval is a string that contains any scheme code that can be executed in Fluent for the current mode.

Surface field and mesh data services are available in solution mode only via the field_data object attribute of the session object:

surface_data = solver_session.field_data.get_fields()

For more information, see Field data.

The connection status of any session can be verified with:

health = solver_session.check_health()

"SERVING" is returned if and only if the connection is healthy.

Streaming

Streaming of a Fluent transcript is automatically started by default. You can stop and start the streaming of a transcript manually with:

solver_session.stop_transcript()

solver_session.start_transcript()

You can enable and disable the streaming of events pertaining to various solver event types via the events_manager attribute of a solution mode session:

solver_session.events_manager.start()

For more information, see EventsManager.

Global logging

You can control the global logging level at any time with:

import ansys.fluent.core as pyfluent
pyfluent.set_log_level('DEBUG') # by default, only errors are shown