use Noca forces in the flow sphere example

Examples/FlowAroundSphere.py

@@ -214,13 +214,13 @@ cb = ControlBox(parent=box, origin=cbpos, length=cblength)
 coeffForce = 1. / (0.5 * uinf ** 2 * pi * RADIUS ** 2)
 
 io_forces=IOParams('drag_and_lift_NocaII')
-#monitors['forcesNoca'] = NocaForces(velo, vorti, 
-#                                    discretization=topo_with_ghosts,
-#                                    nu=VISCOSITY, 
-#                                    volume_of_control=cb,
-#                                    normalization=coeffForce,
-#                                    obstacles=[sphere], 
-#                                    io_params=io_forces)
+monitors['forcesNoca'] = NocaForces(velo, vorti, 
+                                    discretization=topo_with_ghosts,
+                                    nu=VISCOSITY, 
+                                    volume_of_control=cb,
+                                    normalization=coeffForce,
+                                    obstacles=[sphere], 
+                                    io_params=io_forces)
 
 io_forcesPenal=IOParams('drag_and_lift_Mom')
 monitors['forcesMom'] = MomentumForces(velocity=velo, 

HySoP/hysop/operator/discrete/drag_and_lift.py

@@ -405,6 +405,7 @@ class NocaForces(Forces):
         # --- First part of the integral ---
         #  int(0.5 (uu)n - (nu)u)
         # i_n component
+        nbc = self.velocity.nb_components
         res[i_n] += 0.5 * normal * npw.real_sum(
             sum([vd[j][ind] ** 2 for j in i_t]) - vd[i_n][ind] ** 2)
         # other components