This shows you the differences between two versions of the page.
docs:utils:couette [2009/02/13 08:32] gibson created |
docs:utils:couette [2009/02/13 08:45] gibson |
||
---|---|---|---|
Line 23: | Line 23: | ||
[[docs:utils:couette:alloptions|Complete option list]] | [[docs:utils:couette:alloptions|Complete option list]] | ||
- | ==== time intervals ==== | + | ===== time intervals ===== |
The integration starts at ''t=T0'' and saves data at times ''t = T0 + n dT'', exactly. The ''dt'' | The integration starts at ''t=T0'' and saves data at times ''t = T0 + n dT'', exactly. The ''dt'' | ||
Line 29: | Line 29: | ||
so that the save interval is exactly what you asked for. Data is saved to disk in files named ''u0.ff, u1.ff, u2.ff, ...'' if ''t'' takes on integer values or filenames with four-digit precision if ''t'' otherwise, e.g. ''u0.000.ff, u0.125.ff, u0.250.ff, ...''. The integration stops when ''t = T0 + n dT > T1.'' | so that the save interval is exactly what you asked for. Data is saved to disk in files named ''u0.ff, u1.ff, u2.ff, ...'' if ''t'' takes on integer values or filenames with four-digit precision if ''t'' otherwise, e.g. ''u0.000.ff, u0.125.ff, u0.250.ff, ...''. The integration stops when ''t = T0 + n dT > T1.'' | ||
- | ==== timestepping ==== | + | ===== timestepping ===== |
The ''-ts'' or ''--timestepping'' sets the finite-difference time stepping algorithm. It takes the following | The ''-ts'' or ''--timestepping'' sets the finite-difference time stepping algorithm. It takes the following | ||
Line 43: | Line 43: | ||
|''sbdf4''| 4 | Semi-implict Backwards Differentiation| | |''sbdf4''| 4 | Semi-implict Backwards Differentiation| | ||
- | ==== nonlinearity ==== | + | ===== nonlinearity ===== |
+ | |||
+ | The ''-nl'' or ''--nonlinearity'' specifies the method for calculating the | ||
+ | nonlinearity u⋅∇u in the Navier-Stokes equation. | ||
+ | |||
+ | ^ value ^ ^method^ | ||
+ | | ''rot'' | (∇×u)×u |rotational| | ||
+ | | ''conv'' | u⋅∇u |convection| | ||
+ | | ''div'' | ∇⋅(uu) |divergence| | ||
+ | | ''skew'' | (u⋅∇u + ∇⋅(uu))/2 |skew-symmetric| | ||
+ | | ''alt'' | |alternating between ''conv'' and ''div''| | ||
+ | |||
+ | ===== mean constraints ===== | ||
====== Usage examples ====== | ====== Usage examples ====== | ||
- | Integrate |