Enable viscous flux contribution at supersonic outlet boundary condition

SU2_CFD/src/solvers/CEulerSolver.cpp

@@ -7514,6 +7514,7 @@ void CEulerSolver::BC_Supersonic_Outlet(CGeometry *geometry, CSolver **solver_co
   su2double *V_outlet, *V_domain;
 
   bool implicit = (config->GetKind_TimeIntScheme() == EULER_IMPLICIT);
+  bool viscous = config->GetViscous();
   string Marker_Tag = config->GetMarker_All_TagBound(val_marker);
 
   auto *Normal = new su2double[nDim];
@@ -7578,44 +7579,45 @@ void CEulerSolver::BC_Supersonic_Outlet(CGeometry *geometry, CSolver **solver_co
       if (implicit)
         Jacobian.AddBlock2Diag(iPoint, residual.jacobian_i);
 
-//      /*--- Viscous contribution, commented out because serious convergence problems ---*/
-//
-//      if (viscous) {
-//
-//        /*--- Set laminar and eddy viscosity at the infinity ---*/
-//
-//        V_outlet[nDim+5] = nodes->GetLaminarViscosity(iPoint);
-//        V_outlet[nDim+6] = nodes->GetEddyViscosity(iPoint);
-//
-//        /*--- Set the normal vector and the coordinates ---*/
-//
-//        visc_numerics->SetNormal(Normal);
-//        su2double Coord_Reflected[MAXNDIM];
-//        GeometryToolbox::PointPointReflect(nDim, geometry->nodes->GetCoord(Point_Normal),
-//                                                 geometry->nodes->GetCoord(iPoint), Coord_Reflected);
-//        visc_numerics->SetCoord(geometry->nodes->GetCoord(iPoint), Coord_Reflected);
-//
-//        /*--- Primitive variables, and gradient ---*/
-//
-//        visc_numerics->SetPrimitive(V_domain, V_outlet);
-//        visc_numerics->SetPrimVarGradient(nodes->GetGradient_Primitive(iPoint), nodes->GetGradient_Primitive(iPoint));
-//
-//        /*--- Turbulent kinetic energy ---*/
-//
-//        if (config->GetKind_Turb_Model() == TURB_MODEL::SST)
-//          visc_numerics->SetTurbKineticEnergy(solver_container[TURB_SOL]->GetNodes()->GetSolution(iPoint,0),
-//                                              solver_container[TURB_SOL]->GetNodes()->GetSolution(iPoint,0));
-//
-//        /*--- Compute and update residual ---*/
-//
-//        auto residual = visc_numerics->ComputeResidual(config);
-//        LinSysRes.SubtractBlock(iPoint, residual);
-//
-//        /*--- Jacobian contribution for implicit integration ---*/
-//
-//        if (implicit)
-//          Jacobian.SubtractBlock2Diag(iPoint, residual.jacobian_i);
-//      }
+     /*--- Viscous contribution, commented out because serious convergence problems ---*/
+
+     if (viscous) {
+
+       /*--- Set laminar and eddy viscosity at the infinity ---*/
+
+       V_outlet[nDim+5] = nodes->GetLaminarViscosity(iPoint);
+       V_outlet[nDim+6] = nodes->GetEddyViscosity(iPoint);
+
+       /*--- Set the normal vector and the coordinates ---*/
+
+       visc_numerics->SetNormal(Normal);
+       su2double Coord_Reflected[MAXNDIM];
+       unsigned long Point_Normal = geometry->vertex[val_marker][iVertex]->GetNormal_Neighbor();
+       GeometryToolbox::PointPointReflect(nDim, geometry->nodes->GetCoord(Point_Normal),
+                                                geometry->nodes->GetCoord(iPoint), Coord_Reflected);
+       visc_numerics->SetCoord(geometry->nodes->GetCoord(iPoint), Coord_Reflected);
+
+       /*--- Primitive variables, and gradient ---*/
+
+       visc_numerics->SetPrimitive(V_domain, V_domain);
+       visc_numerics->SetPrimVarGradient(nodes->GetGradient_Primitive(iPoint), nodes->GetGradient_Primitive(iPoint));
+
+       /*--- Turbulent kinetic energy ---*/
+
+       if (config->GetKind_Turb_Model() == TURB_MODEL::SST)
+         visc_numerics->SetTurbKineticEnergy(solver_container[TURB_SOL]->GetNodes()->GetSolution(iPoint,0),
+                                             solver_container[TURB_SOL]->GetNodes()->GetSolution(iPoint,0));
+
+       /*--- Compute and update residual ---*/
+
+       auto residual = visc_numerics->ComputeResidual(config);
+       LinSysRes.SubtractBlock(iPoint, residual);
+
+       /*--- Jacobian contribution for implicit integration ---*/
+
+       if (implicit)
+         Jacobian.SubtractBlock2Diag(iPoint, residual.jacobian_i);
+     }
 
     }
   }

TestCases/2d_plate/lam_flatplate.cfg

@@ -0,0 +1,102 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%                                                                              %
+% SU2 configuration file                                                       %
+% Case description: Supersonic flat plate flow                                 %
+% Author: Tan Yilun                                                            %
+% Institution: University of Chinese Academy of Sciences                       %
+% Date: 2026.05.22                                                             %
+% File Version 8.0.1                                                           %
+%                                                                              %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% ------------- Solver ------------%
+SOLVER= NAVIER_STOKES       % Governing eqs: compressible Navier-Stokes
+KIND_TURB_MODEL= NONE       % Laminar (no turbulence model)
+MATH_PROBLEM= DIRECT        % Direct (not adjoint)
+
+% ------------- Time Integration ------------%
+%TIME_DOMAIN= NO                 % Unsteady simulation
+%TIME_MARCHING= DUAL_TIME_STEPPING-2ND_ORDER % Dual time stepping
+%TIME_STEP= 1E-6                  % Physical time step (s)
+%INNER_ITER= 20                 % Max inner iterations per physical time step
+%TIME_ITER= 100000.0
+
+CFL_NUMBER= 0.1              % CFL number
+CFL_ADAPT= NO              % Adaptive CFL
+CFL_ADAPT_PARAM= ( 0.3, 1.05, 0.01, 5)
+ITER= 100000                 % Max iterations
+TIME_DISCRE_FLOW= EULER_EXPLICIT
+OUTPUT_WRT_FREQ= 100000       % Write output every xxxx iters
+
+% ------------- In & Output ------------%
+RESTART_SOL= NO        % Start from scratch, not a restart
+SOLUTION_FILENAME= restart_flow.dat
+
+MESH_FILENAME= grid2.cgns
+MESH_FORMAT= CGNS
+
+TABULAR_FORMAT= TECPLOT
+CONV_FILENAME= history
+RESTART_FILENAME= restart_flow
+VOLUME_FILENAME= volume_flow
+SURFACE_FILENAME= surface_flow
+WRT_RESTART_OVERWRITE= YES   
+WRT_SURFACE_OVERWRITE= NO   % Append iter# to surface files
+WRT_VOLUME_OVERWRITE= NO    % Append iter# to volume files
+OUTPUT_FILES= (RESTART, TECPLOT, SURFACE_CSV)
+SCREEN_OUTPUT=(INNER_ITER, WALL_TIME, AVG_CFL, RMS_DENSITY, RMS_MOMENTUM-X,RMS_MOMENTUM-Y,RMS_ENERGY,DRAG,LIFT)
+
+% ------------- Freestream Conditions ------------%
+MACH_NUMBER= 4.0            % Freestream Mach number
+AOA= 0.0                    
+SIDESLIP_ANGLE= 0.0         
+INIT_OPTION= TD_CONDITIONS  % Initialize from P, T
+% FREESTREAM_OPTION= TEMPERATURE_FS
+FREESTREAM_TEMPERATURE= 300.0
+REYNOLDS_NUMBER= 12314
+FREESTREAM_PRESSURE= 70.47  
+REYNOLDS_LENGTH= 0.2        
+
+% ------------- Transport properties ------------%
+%FLUID_MODEL= IDEAL_GAS      % Ideal gas law
+%GAMMA_VALUE= 1.4
+%GAS_CONSTANT= 287.058      
+
+%VISCOSITY_MODEL= SUTHERLAND 
+%MU_REF= 1.716E-5
+%MU_T_REF= 273.15
+%SUTHERLAND_CONSTANT= 110.4
+
+%CONDUCTIVITY_MODEL= CONSTANT_PRANDTL
+%PRANDTL_LAM= 0.72
+
+% ------------- Boundary Conditions ------------%
+MARKER_ISOTHERMAL= ( WALL, 300.0 )    % No-slip isothermal wall at 300 K
+MARKER_SYM= ( SYMMETRY )              % Symmetry plane
+MARKER_FAR= ( INLET )                 % Far-field inlet
+% MARKER_SUPERSONIC_INLET = (INLET, 300.0,70.47,1388.755,0,0)
+MARKER_SUPERSONIC_OUTLET= ( OUTLET )  % Supersonic outlet
+MARKER_PLOTTING= ( WALL )             % Surface output marker
+MARKER_MONITORING= ( WALL )           % Force monitoring marker
+
+% ------------- Numerical Methods ------------%
+CONV_NUM_METHOD_FLOW= AUSM  % Convective flux scheme
+MUSCL_FLOW= YES             % 2nd-order MUSCL reconstruction
+SLOPE_LIMITER_FLOW= VENKATAKRISHNAN_WANG
+VENKAT_LIMITER_COEFF= 0.05
+% RAMP_MUSCL= YES
+% RAMP_MUSCL_COEFF= (1000.0, 10.0, 500.0)
+
+NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES
+LINEAR_SOLVER= BCGSTAB
+LINEAR_SOLVER_PREC= LU_SGS
+LINEAR_SOLVER_ERROR= 1E-10
+LINEAR_SOLVER_ITER= 10
+
+MGLEVEL= 0                  % No multigrid
+
+% ------------- Convergence criteria ------------%
+CONV_FIELD= RMS_ENERGY
+CONV_RESIDUAL_MINVAL= -5
+CONV_STARTITER= 10
+