[cig-commits] r8216 - doc/CitcomS/manual

[tan2 at geodynamics.org]

Author: tan2
Date: 2007-11-06 16:30:26 -0800 (Tue, 06 Nov 2007)
New Revision: 8216

Modified:
   doc/CitcomS/manual/citcoms.lyx
Log:
Updated for new cookbook7.cfg. Added convergence parameters for cgrad solver.

Modified: doc/CitcomS/manual/citcoms.lyx
===================================================================
--- doc/CitcomS/manual/citcoms.lyx	2007-11-06 23:18:54 UTC (rev 8215)
+++ doc/CitcomS/manual/citcoms.lyx	2007-11-07 00:30:26 UTC (rev 8216)
@@ -9563,8 +9563,8 @@
 tracer_ic_method=0
 \family default
 .
- The tracers will be generated pseudo-randomly automatically, with a total
- number equal to 
+ The tracers will be generated pseudo-randomly, with a total number equal
+ to 
 \end_layout
 
 \begin_layout LyX-Code
@@ -9681,14 +9681,14 @@
 \end_inset
 
 .
- The density anomaly of the anomalous chemical composition is 0.4.
+ The density anomaly of the anomalous chemical composition is 0.5.
  
 \end_layout
 
 \begin_layout LyX-Code
 buoy_type = 1
 \newline
-buoyancy_ratio = 0.4
+buoyancy_ratio = 0.5
 \end_layout
 
 \begin_layout Standard
@@ -9749,6 +9749,83 @@
  The regional spherical version does not have this constraint.
 \end_layout
 
+\begin_layout Standard
+You will use the conjugate gradient solver to solve the matrix equation
+ 
+\begin_inset Formula $\mathbf{A}x=b$
+\end_inset
+
+ for x.
+ The conjugate gradient solver is more efficient than the multigrid solver
+ (
+\family typewriter
+Solver=multigrid
+\family default
+) for small problems (e.g.
+ less than 17
+\begin_inset Formula $\times$
+\end_inset
+
+17
+\begin_inset Formula $\times$
+\end_inset
+
+17 nodes per processor).
+ The desired accuracy and maximum iterations are set by 
+\family typewriter
+accuracy
+\family default
+ and 
+\family typewriter
+vlowstep
+\family default
+.
+ For the Uzawa algorithm, the desired accuracy for the continuity equation
+ (Equation 
+\begin_inset LatexCommand ref
+reference "eq:discrete continuite eqn"
+
+\end_inset
+
+) and maximum iterations are set by 
+\family typewriter
+tole_compressibility
+\family default
+ and 
+\family typewriter
+piterations
+\family default
+.
+ 
+\family typewriter
+vlowstep 
+\family default
+and 
+\family typewriter
+piterations
+\family default
+ should be large integers, but you can experiment with a larger value for
+ 
+\family typewriter
+accuracy
+\family default
+ to speed up the computation.
+ 
+\end_layout
+
+\begin_layout LyX-Code
+Solver = cgrad
+\newline
+accuracy = 1e-06
+\newline
+vlowstep = 1000
+\newline
+tole_compressibility = 1e-07
+\newline
+piterat
+ions = 1000
+\end_layout
+
 \begin_layout Subsubsection
 Example: Thermo-Chemical Convection, 
 \family typewriter
@@ -9760,7 +9837,7 @@
 \newline
 solver = full
 \newline
-steps = 30                 ; number of time steps
+steps = 15                 ; number of time steps
 \newline
 
 \newline
@@ -9769,7 +9846,7 @@
 [CitcomS.c
 ontroller]
 \newline
-monitoringFrequency = 10   ; how often outputs are created
+monitoringFrequency = 5    ; how often outputs are created
 \newline
 
 \newline
@@ -9842,7 +9919,7 @@
 buoy_type
  = 1
 \newline
-buoyancy_ratio = 0.4
+buoyancy_ratio = 0.5
 \newline
 
 \newline
@@ -9854,17 +9931,34 @@
 \newline
 
 \newline
-#
- Assign the viscosities.
+[Citcom
+S.solver.vsolver]
 \newline
+Solver = cgrad
+\newline
+accuracy = 1e-06
+\newline
+vlowstep = 1000
+\newline
+tole_compressibility
+ = 1e-07
+\newline
+piterations = 1000
+\newline
+
+\newline
+
+\newline
+# Assign the viscosities.
+\newline
 [CitcomS.solver.visc]
 \newline
-VISC_UPDATE = on
+VISC_UPDATE
+ = on
 \newline
 num_mat = 4
 \newline
-visc0
- = 1,1,1,1
+visc0 = 1,1,1,1
 \newline
 TDEPV = on
 \newline
@@ -9872,10 +9966,10 @@
 \newline
 viscT = 0,0,0,0
 \newline
-VMIN = on
+VMIN
+ = on
 \newline
-visc_min
- = 1.0
+visc_min = 1.0
 \newline
 VMAX = on
 \end_layout
@@ -9893,8 +9987,8 @@
 \noindent
 \align center
 \begin_inset Graphics
-	filename graphics/cookbook7.jpg
-	lyxscale 30
+	filename graphics/cookbook7.png
+	lyxscale 50
 	scale 90
 
 \end_inset
@@ -9911,7 +10005,7 @@
 
 \end_inset
 
-Cookbook 7: The composition and velocity field at the 20th step.
+Cookbook 7: The composition and velocity field at the 15th step.
  The arrows are the velocity vectors.
  The composition field is shown in an isosurface of 0.7 and in a cross section.
 \end_layout
@@ -9940,7 +10034,7 @@
 .
  The buoyancy ratio in this model is too low to stabilize the chemical layer.
  A few thermo-chemical plumes are rising from the lower mantle, especially
- the ones at the 4, 11, and 12 o'clock directions.
+ the ones at the 4, 6, 9, 10, and 12 o'clock directions.
  The resolution of this model is fairly low.
  The composition isosurface is slightly discontinuous across the cap boundary.
  A model of higher resolution will not have this kind of artifact.