# Submit Jobs

Use the Run VWT tool to specify the simulation time for a transient run and other setup parameters, as well as submit the actual analysis.

## Define Settings in the Write to ultraFluidX Dialog

Before submitting a job in the Write to ultraFluidX dialog, define the Analysis setup settings.

### Analysis Setup

- Inflow speed
- Prescribed inflow velocity at the inflow surface of the wind tunnel going into positive x-direction.
- Run time
- Physical run time for a transient analysis.
- Time step
- Time increment used for the transient analysis.
- Smooth start iterations
- Set the number of steps used by the solver to ramp up inflow and fan speeds.
- Allow time step scaling
- Allow ultraFluidX to run the simulation at an elevated Mach Number to reduce the total number of time steps required to complete the run.
- Maximum velocity factor
- The scaling factor used to derive the maximum expected velocity within the simulation from the wind tunnel inflow speed. The maximum expected velocity is calculated as the product of the inflow speed and the maximum velocity factor. This quantity is then used to derive the time step scaling factor when time step scaling is active.
- Scaling factor
- The scaling factor that is used to increase the time step size when time step scaling is active. This value is computed automatically based on the maximum velocity factor, inflow speed, and peak Mach Number supported by the ultraFluidX solver.
- Number of steps
- Number of time steps for a transient analysis.
- Fluid material
- Fluid material model to use in the simulation.
- Simulation mode
- Set default solver settings based on simulation objective. Select external aerodynamics or fan noise.
- Precursor simulation
- Run a coarse precursor simulation to accelerate steady state convergence of a full simulation. See precursorRun Script for more information.
- Coarsening factor
- Define the mesh coarseness of the precursor simulation.
- Moving ground
- Models the wind tunnel ground as a moving wall with a translational velocity equal to the inflow velocity.
- Rotating wheels
- Models parts identified as wheels as a wall, and a rotational velocity is prescribed.
- Mesh preview
- Write the mesh to disk before running the simulation.
- Export mesh
- Write the mesh to disk for re-use in a subsequent run.