added: MultisegmentWellEquations::createSolver

this applies compute the LU decomposition of the D matrix

opm/simulators/wells/MultisegmentWellEquations.cpp

@@ -22,9 +22,15 @@
 #include <config.h>
 #include <opm/simulators/wells/MultisegmentWellEquations.hpp>
 
+#include <dune/istl/umfpack.hh>
+
+#include <opm/common/ErrorMacros.hpp>
+
 #include <opm/simulators/wells/MSWellHelpers.hpp>
 #include <opm/simulators/wells/MultisegmentWellGeneric.hpp>
 
+#include <stdexcept>
+
 namespace Opm {
 
 template<class Scalar, int numWellEq, int numEq>
@@ -140,6 +146,21 @@ apply(BVector& r) const
     duneC_.mmtv(invDrw, r);
 }
 
+template<class Scalar, int numWellEq, int numEq>
+void MultisegmentWellEquations<Scalar,numWellEq,numEq>::createSolver()
+{
+#if HAVE_UMFPACK
+    if (duneDSolver_) {
+        return;
+    }
+
+    duneDSolver_ = std::make_shared<Dune::UMFPack<DiagMatWell>>(duneD_, 0);
+#else
+    OPM_THROW(std::runtime_error, "MultisegmentWell support requires UMFPACK. "
+              "Reconfigure opm-simulators with SuiteSparse/UMFPACK support and recompile.");
+#endif
+}
+
 #define INSTANCE(numWellEq, numEq) \
 template class MultisegmentWellEquations<double,numWellEq,numEq>;
 

opm/simulators/wells/MultisegmentWellEquations.hpp

@@ -80,6 +80,9 @@ public:
     //! \brief Apply linear operator to vector.
     void apply(BVector& r) const;
 
+    //! \brief Compute the LU-decomposition of D matrix.
+    void createSolver();
+
     // two off-diagonal matrices
     OffDiagMatWell duneB_;
     OffDiagMatWell duneC_;

opm/simulators/wells/MultisegmentWell_impl.hpp

@@ -1776,6 +1776,8 @@ namespace Opm
                 this->assemblePressureEq(seg, unit_system, well_state, deferred_logger);
             }
         }
+
+        this->linSys_.createSolver();
     }