Time Derivatives

Time Derivatives = {yes | no}

Description / Usage

This option enables writing the time derivative of all the field variables as nodal variables to the output EXODUS II file. These variables are labeled XDOT0 (mesh velocity in x direction), XDOT1 (mesh velocity in y direction), XDOT2 (mesh velocity in z direction), VDOT0 (fluid acceleration in x direction), VDOT1 (fluid acceleration in y direction), VDOT2 (fluid acceleration in z direction), TDOT (rate of temperature change), Y0DOT (rate of 1st species concentration change), Y1D0T (rate of second species concentration change), and so on. The quantities can then be contoured or displayed by some other means with a visualization or graphics package.

The permissible values for this postprocessing option are:

yes	Calculate the time derivatives and write them as nodal variables in the output EXODUS II file.
no	Do not calculate the time derivatives.

Examples

The following sample card requests that time derivatives be written to the EXODUS II file:

Time Derivatives = yes

Technical Discussion

Currently, this routine uses the values in the global vector xdot to report this data. During the first time step, all the xdot values are zero; by the second time step, these data should be realistic.

References

No References.