# DERIVED_QUANTITY_OUTPUT

Specifies nodal output parameters for derived quantities.

AcuSolve Command

## Syntax

DERIVED_QUANTITY_OUTPUT {parameters}

## Qualifier

This command has no qualifier.

## Parameters

output_frequency or out_freq (integer) >=0 [0]
Time step frequency at which to output nodal derived quantities. If zero, this option is ignored.
output_time_interval or out_intv (real) >=0 [=0]
Time frequency at which to output nodal derived quantities. If zero, this option is ignored.
num_saved_states or save (integer) >=0 [=0]
Number of nodal derived quantity files to keep. If zero, all are kept.

## Description

"Nodal derived quantities" are the nodal projections of material model quantities, body forces, and turbulence data. This command specifies the frequency at which nodal derived quantities are written into a results database on disk. For example,
DERIVED_QUANTITY_OUTPUT {
output_frequency      = 10
output_time_interval  = 2.5
}

specifies that the nodal derived quantities are to be output at every 10 time steps, at every 2.5 units of run time and at the last time step.

Once the nodal derived quantities have been written to disk, they can be translated to other formats using the AcuTrans program and other post-processing modules; see the AcuSolve Programs Reference Manual for details.

If either output_frequency or output_time_interval is non-zero, the nodal derived quantities will be output at the end of the run. If both are zero, no data are written to disk.

Run times may not coincide with output_time_interval. In this case, at every time step which passes through a multiple of output_time_interval, the nodal derived quantities are output.

The num_saved_states parameter indicates the number of nodal derived quantity files to save. Once the (num_saved_states + 1)th file is written, the first one is removed. When running in parallel, once all files are written (in parallel), then the old ones are removed (in parallel).