diff --git a/dumux/freeflow/zeroeqnc/fluxvariables.hh b/dumux/freeflow/zeroeqnc/fluxvariables.hh
index 5cf4770a33231f692892bdd22641c9cf730f12d9..c35c80eccf18ffea094ff7ff215c6d0b399fea56 100644
--- a/dumux/freeflow/zeroeqnc/fluxvariables.hh
+++ b/dumux/freeflow/zeroeqnc/fluxvariables.hh
@@ -101,12 +101,7 @@ public:
 
         // Richardson number
         // Schlichting, Boundary Layer Theory, 1997, p472
-        Scalar gravity = 0.0;
-        if (GET_PARAM_FROM_GROUP(TypeTag, bool, Problem, EnableGravity))
-            gravity = problem.gravity()[wallNormal_];
-        else
-            gravity = 9.81;
-        richardsonNumber_ = -gravity / this->density()
+        richardsonNumber_ = problem.gravity()[wallNormal_] / this->density()
                             * densityGrad()[wallNormal_] / (velGradWall_ * velGradWall_);
 
         // calculation of an eddy diffusivity only makes sense with Navier-Stokes equation
diff --git a/dumux/multidomain/properties.hh b/dumux/multidomain/properties.hh
index 06c04b574070a87df5b0f65146178587546c3549..c76e3cc61889d223b8ce1b36b4a2d31eebc79cab 100644
--- a/dumux/multidomain/properties.hh
+++ b/dumux/multidomain/properties.hh
@@ -49,6 +49,9 @@ NEW_TYPE_TAG(MultiDomain, INHERITS_FROM(ImplicitBase));
 //! Specifies the model
 NEW_PROP_TAG(Model);
 
+//! Specifies the maximum number of sub-problems
+NEW_PROP_TAG(MaxSubDomains);
+
 //! Specifies the type tag of the first sub-problem
 NEW_PROP_TAG(SubDomain1TypeTag);
 
diff --git a/dumux/multidomain/propertydefaults.hh b/dumux/multidomain/propertydefaults.hh
index db6a538524a1ed44f3e810cd7411f0a39f2f22a1..b3f837bac32de8113070c0f4e9a27f1275b61e0b 100644
--- a/dumux/multidomain/propertydefaults.hh
+++ b/dumux/multidomain/propertydefaults.hh
@@ -59,11 +59,14 @@ template <class TypeTag> class MultiDomainNewtonController;
 namespace Properties
 {
 
+SET_INT_PROP(MultiDomain, MaxSubDomains, 2);
+
 SET_PROP(MultiDomain, MultiDomainGrid)
 {
 private:
     typedef typename GET_PROP_TYPE(TypeTag, Grid) HostGrid;
-    typedef typename Dune::mdgrid::FewSubDomainsTraits<HostGrid::dimension,4> MDGridTraits;
+    enum { maxSubDomains = GET_PROP_VALUE(TypeTag, MaxSubDomains) };
+    typedef typename Dune::mdgrid::FewSubDomainsTraits<HostGrid::dimension, maxSubDomains> MDGridTraits;
 public:
     typedef typename Dune::MultiDomainGrid<HostGrid, MDGridTraits> type;
 };
diff --git a/dumux/multidomain/subdomainpropertydefaults.hh b/dumux/multidomain/subdomainpropertydefaults.hh
index e1227178637d170eca18d7f3a27cf55ee5f15b24..6e2d40d263366af64f6d1807b69d7ee07d477ebb 100644
--- a/dumux/multidomain/subdomainpropertydefaults.hh
+++ b/dumux/multidomain/subdomainpropertydefaults.hh
@@ -49,7 +49,8 @@ SET_PROP(SubDomain, Grid)
 private:
     typedef typename GET_PROP_TYPE(TypeTag, MultiDomainTypeTag) MultiDomain;
     typedef typename GET_PROP_TYPE(MultiDomain, Grid) HostGrid;
-    typedef typename Dune::mdgrid::FewSubDomainsTraits<HostGrid::dimension,4> MDGridTraits;
+    enum { maxSubDomains = GET_PROP_VALUE(MultiDomain, MaxSubDomains) };
+    typedef typename Dune::mdgrid::FewSubDomainsTraits<HostGrid::dimension,maxSubDomains> MDGridTraits;
     typedef typename Dune::MultiDomainGrid<HostGrid, MDGridTraits> Grid;
 public:
     typedef typename Grid::SubDomainGrid type;
diff --git a/test/multidomain/2cnistokes2p2cni/2cnistokes2p2cniproblem.hh b/test/multidomain/2cnistokes2p2cni/2cnistokes2p2cniproblem.hh
index 4fb12df0b4955a9893fa890b1fab4ef6fc510bdf..4c267d66626461366d582337d052599adff4a552 100644
--- a/test/multidomain/2cnistokes2p2cni/2cnistokes2p2cniproblem.hh
+++ b/test/multidomain/2cnistokes2p2cni/2cnistokes2p2cniproblem.hh
@@ -135,7 +135,7 @@ public:
      */
     template<class GridView>
     TwoCNIStokesTwoPTwoCNITestProblem(TimeManager &timeManager,
-                                  GridView gridView)
+                                      GridView gridView)
     : ParentType(timeManager, gridView)
     {
         interfacePosY_ = GET_RUNTIME_PARAM_FROM_GROUP(TypeTag, Scalar, Grid, InterfacePosY);
diff --git a/test/multidomain/2czeroeq2p2c/2czeroeq2p2cproblem.hh b/test/multidomain/2czeroeq2p2c/2czeroeq2p2cproblem.hh
index fa52a6114060b9f90f53f784bfed739a443f4a82..f8b64bd5ac5ef6131121bb4a7a235f6165cb90e8 100644
--- a/test/multidomain/2czeroeq2p2c/2czeroeq2p2cproblem.hh
+++ b/test/multidomain/2czeroeq2p2c/2czeroeq2p2cproblem.hh
@@ -120,7 +120,7 @@ public:
      */
     template<class GridView>
     TwoCZeroEqTwoPTwoCTestProblem(TimeManager &timeManager,
-                              GridView gridView)
+                                  GridView gridView)
     : ParentType(timeManager, gridView)
     {
         dtInit_ = GET_RUNTIME_PARAM_FROM_GROUP(TypeTag, Scalar, TimeManager, DtInitial);