When doing stellar or AGN feedback, set the particles' viscosity to the maximal value.

src/black_holes/EAGLE/black_holes_iact.h

@@ -134,6 +134,9 @@ runner_iact_nonsym_bh_feedback(const float r2, const float *dx, const float hi,
 
       hydro_set_physical_internal_energy(pj, xpj, cosmo, u_new);
       hydro_set_drifted_physical_internal_energy(pj, cosmo, u_new);
+
+      /* Impose maximal viscosity */
+      hydro_set_viscosity_alpha_max_feedback(pj);
     }
   }
 

src/feedback/EAGLE/feedback_iact.h

@@ -300,6 +300,9 @@ runner_iact_nonsym_feedback_apply(const float r2, const float *dx,
       hydro_set_physical_internal_energy(pj, xpj, cosmo, u_new);
       hydro_set_drifted_physical_internal_energy(pj, cosmo, u_new);
 
+      /* Impose maximal viscosity */
+      hydro_set_viscosity_alpha_max_feedback(pj);
+
       /* message( */
       /*     "We did some heating! id %llu star id %llu probability %.5e " */
       /*     "random_num %.5e du %.5e du/ini %.5e", */