basic.H

XiModel.H
SCOPELaminarFlameSpeed.H
basicXiSubXiEq.H
basicXiSubG.H
Doxyfile (include PATH to OpenCFD Macros)
doxyFilt (include class documentation in /src)

applications/solvers/combustion/PDRFoam/XiModels/XiModel/XiModel.H

@@ -27,6 +27,53 @@ Class
 
 Description
     Base-class for all Xi models used by the b-Xi combustion model.
+    See Technical Report SH/RE/01R for details on the PDR modelling.
+
+    Xi is given through an algebraic expression (algebraic.H), by solving a transport equation (transport.H) or a fixed value (fixed.H). See report
+    TR/HGW/10 for details on the Weller two equations model.
+
+    In the algebraic and transport methods \f$\Xi_{eq}\f$ is calculated in
+    similar way. In the algebraic approach, \f$\Xi_{eq}\f$ is the value used in
+    the \f$ b \f$ transport equation.
+
+    \f$\Xi_{eq}\f$ is calculated as follows:
+
+    \f$\Xi_{eq} = 1 + (1 + 2\Xi_{coeff}(0.5 - \dwea{b}))(\Xi^* - 1)\f$
+
+    where:
+
+        \f$ \dwea{b} \f$ is the regress variable.
+
+        \f$ \Xi^* \f$ is the total equilibrium wrinkling combining the effects
+        of the flame inestability and turbulence interaction and is given by
+
+        \f[
+            \Xi^* = \frac {R}{R - G_\eta - G_{in}}
+        \f]
+
+    where:
+
+        \f$ G_\eta \f$ is the generation rate of wrinkling due to turbulence interaction.
+
+        \f$ G_{in} = \kappa \rho_{u}/\rho_{b} \f$ is the generation
+         rate due to the flame inestability.
+
+    By adding the removal rates of the two effects:
+
+        \f[
+            R = G_\eta \frac{\Xi_{\eta_{eq}}}{\Xi_{\eta_{eq}} - 1}
+              + G_{in} \frac{\Xi_{{in}_{eq}}}{\Xi_{{in}_{eq}} - 1}
+        \f]
+
+    where:
+
+        \f$ R \f$ is the total removal.
+        \f$ G_\eta \f$ is a model constant.
+
+        \f$ \Xi_{\eta_{eq}} \f$ is the flame wrinkling due to turbulence.
+
+        \f$ \Xi_{{in}_{eq}} \f$ is the equilibrium level of the flame wrinkling generated by inestability. It is a constant (default 2.5).
+
 
 SourceFiles
     XiModel.C
@@ -51,6 +98,8 @@ namespace Foam
                           Class XiModel Declaration
 \*---------------------------------------------------------------------------*/
 
+
+
 class XiModel
 {