I/O Options and Subcase Information Entry The THERMAL command can be used in the I/O Options or Subcase Information sections to request temperature output for all heat transfer analysis subcases or individual heat transfer analysis subcases, respectively.


THERMAL (sorting, format_list), THRESH=thresh, RTHRESH=rthresh, TOP=topn, RTOP=rtop, SUBSYS=SUBSYS_ID)= option


Argument Options Description
sorting <SORT1, SORT2, blank> Only applies to the PUNCH format (.pch format) for Transient Heat Transfer Subcase. It will be ignored without warning, if used elsewhere.
Results for each timestep are grouped together.
SORT2 (Default)
Results for each Grid/Element are grouped together.
SORT2 is the default for transient heat transfer analysis.
format <PUNCH, OP2, PLOT, H3D, blank>
Results are output in Nastran punch results format (.pch file).
Results are output in Nastran output2 format (.op2 file). 6
Results are output in Nastran output2 format (.op2 file) when PARAM,POST is defined in the Bulk Data section.
Results are output in Hyper3D format (.h3d file).
blank (Default)
Results are output in all active formats for which the result is available.
THRESH <thresh>


Default = blank

Specifies an absolute threshold under which temperature results should not be output. 7
RTHRESH <rthresh>

0.0 < Real < 1.0

Default = blank

Specifies a relative threshold, as a fraction of the maximum temperature, under which results should not be output. For example, if T is the maximum temperature in the model, then temperature results below T*rthresh are excluded from the output.
TOP <topn>

Integer > 0

Default = blank

Only the top "topn" temperature values should be output.
RTOP <rtop>

0.0 < Real < 1.0

Default = blank

Only the top fraction "rtop" of the total number of temperature values should be output. For example, if TTOT is the total number of temperature values in the model, then only the top TTOT*rtop values are output.

No default

ID of the subsystem.

When used along a subsystem definition, this option generates an individual result file for each subsystem with results for that subsystem only.

For more information, refer to the SET Bulk Data Entry.
option <YES, ALL, NO, NONE, SID>

Default = ALL

YES, ALL, blank
Thermal results are output at all grid points for which temperature results are available.
Thermal results are not output.
If a set ID is specified, Thermal results are output only for grid points referenced by that set.


  1. Thermal output is only available for the heat transfer analysis solution sequence.
  2. The PUNCH output produces TEMP Bulk Data Entries, and the SID on the entries will be the subcase number (=1 if no SUBCASES are specified).
  3. Multiple formats are allowed on the same entry; these should be comma separated. If a format is not specified, this output control applies to all formats defined by the OUTPUT command, for which the result is available.
  4. Temperature output via the THERMAL output request is available for both Linear Steady-State Heat Transfer and Linear Transient Heat Transfer Analyses.
  5. Multiple instances of this card are allowed. If instances are conflicting, the last instance dominates.
  6. format=OUTPUT2 can also be used to request results to be output in the Nastran output2 format (.op2 file).
  7. The threshold options (THRESH, RTHRESH, TOP, and RTOP) are available for Thermal and Transient Thermal Analyses only. Transient Thermal Analysis is not supported in OP2 format. SORT1 option should be specified for PUNCH file output to be used in HFILE-based Nonlinear One Step Transient Thermal Stress Analysis (NL-OSTTS). For H3D, the filter is applied to each dimension of elements (shells, solids, beams, welds, etc.), while for OP2 and PUNCH, it is applied to each element type (quad4, tria3, quad8, etc.).