diff --git a/HySoP/hysop/problem/navier_stokes.py b/HySoP/hysop/problem/navier_stokes.py
index 61144ab25ea20c4405db0cb48113476c77591860..f40c5284e0db709e8a9b6ddd61a56c01c730cdfe 100644
--- a/HySoP/hysop/problem/navier_stokes.py
+++ b/HySoP/hysop/problem/navier_stokes.py
@@ -14,9 +14,11 @@ class NSProblem(Problem):
     """
     Navier Stokes problem description.
     """
-    def __init__(self, operators=[], monitors=[]):
-        Problem.__init__(self, operators, monitors)
-        self.velocity = None
+    def __init__(self, operators, simulation, monitors=[],
+                 dumpFreq=100, name=None):
+
+        Problem.__init__(self, operators, simulation,
+                         monitors, dumpFreq, name)
         for op in operators:
             if isinstance(op, Advection):
                 self.advection = op
@@ -30,25 +32,3 @@ class NSProblem(Problem):
                 self.penal = op
             if isinstance(op, Analytic):
                 self.velocity = op
-
-#    def setUp(self, t_end, dt,
-#              advection_config=None,
-#              stretch_config=None,
-#              diffusion_config=None,
-#              poisson_config=None,
-#              penal_config=None):
-##        if velocity_config is None and self.velocity is not None:
-##            raise ValueError("A configuration for velocity operator" +
-##                             " is required")
-#        Problem.setUp(self, t_end, dt)
-#        if self.advection is not None:
-#            self.advection.setUp(**advection_config)
-#        if self.stretch is not None:
-#            self.stretch.setUp(**stretch_config)
-#        if self.diffusion is not None:
-#            self.diffusion.setUp(**diffusion_config)
-#        if self.poisson is not None:
-#            self.poisson.setUp(**poisson_config)
-#        if self.penal is not None:
-#            self.penal.setUp(**penal_config)
-#        self._collect_topologies()