/DT/ALE
Engine Keyword Time step control for ALE or EULER cells.
Format
ΔTsca ΔTmin
Definition
Field | Contents | SI Unit Example |
---|---|---|
ΔTsca | Scale factor on
critical time step. Default = 0.5 |
|
ΔTmin | Minimum time step. | [s] |
Comments
- If the ALE time step becomes less than ΔTmin , then the simulation will stop and a restart file will be written.
- As of the 2018.0 release, /DT/BRICK and /DT/QUAD are only relevant for Lagrangian elements.
- As of the 2018.0 release, time step for ALE or EULER cells can only be controlled with /DT/ALE. This allows the time step control for the ALE cells to be different when you have both Lagrangian and ALE bricks in the input file.
- By default, scale factor ΔTsca
is 0.5 which is the recommended value for ALE or EULER
cells. As a result, if you did not use /DT or
/DT/BRICK or /DT/QUAD with
ΔTsca
=0.5, you will have by default, different time step from
version 2018.0. To retrieve your previous result, you must set the relevant time
step with /DT/ALE.
- 2017.0 Engine File
- 2018.0 Engine File
- /DT/BRICK with ΔTsca =0.3
- Add /DT/ALE with ΔTsca =0.3
- /DT/QUAD with ΔTsca =0.0
- Add /DT/QUAD with ΔTsca =0.9
- /DT with ΔTsca =0.4
- Not applicable
- No time step control
- Add /DT/ALE with ΔTsca =0.9 (3D case), or