# Specify solver settings#

PyFluent supports using Solver TUI commands and Solver settings objects to specify solver settings.

The examples on this page show how to use Solver TUI commands to specify solver settings.

## Set steady or transient solution model#

This example shows a comparison between the TUI commands and the Python code for enabling and disabling the steady and unsteady (transient) solution model.

**TUI command**

```
/define/models/steady yes
/define/models/unsteady_1st_order yes
```

**Python code**

```
import ansys.fluent.core as pyfluent
solver = pyfluent.launch_fluent(precision="double", processor_count=2, mode="solver")
solver.tui.file.read_case("file.cas.h5")
solver.tui.define.models.steady("yes")
solver.tui.define.models.unsteady_1st_order("yes")
```

## Set a pressure-based or density-based solver#

This example shows a comparison between the TUI commands and the Python code for enabling and disabling the pressure-based and density-based solver models.

**TUI command**

```
/define/models/solver/density-based-explicit yes
/define/models/solver/density-based-implicit yes
/define/models/solver/pressure-based yes
```

**Python code**

```
solver.tui.define.models.solver.density_based_explicit("yes")
solver.tui.define.models.solver.density_based_implicit("yes")
solver.tui.define.models.solver.pressure_based("yes")
```

## Set gravitational acceleration#

This example shows a comparison between the TUI command and the Python code for setting the gravitational acceleration.

**TUI command**

```
/define/operating-conditions/gravity yes 0 -9.81 0
```

**Python code**

```
solver.tui.define.operating_conditions.gravity("yes","0","-9.81","0")
```