Kratos: Help needed! FSI Application (GiD v15, Kratos 7.0.2 Mok Example)

[SamiBidier]

Dear Kratos team,
I'm fairly new in the kratos community and am trying to set up a fsi simulation in 3d. I tried basing my application on the mok example, which, however, is not running after meshing (GiD v15, Kratos 7.0.2)

From GiD I get the following warning

resulting in the kratos error

This is without changing anythin in the example. Could someone verify the behaviour and give me assistance? @rubenzorrilla maybe?

Thanks in advance,
Sami

[rubenzorrilla]

Dear @SamiBidier ,

It seems that you have not assigned any GiD group in Fluid --> Conditions --> FSI fluid interface. Can you post the generated ProjectParameters.json file here?

[SamiBidier]

Hi,
thanks for the quick response. here is the json file:

{
"problem_data" : {
"problem_name" : "test_mik",
"parallel_type" : "OpenMP",
"echo_level" : 0,
"start_time" : 0.0,
"end_time" : 25.0
},
"solver_settings" : {
"solver_type" : "Partitioned",
"coupling_scheme" : "DirichletNeumann",
"echo_level" : 1,
"structure_solver_settings" : {
"solver_type" : "Dynamic",
"model_part_name" : "Structure",
"domain_size" : 3,
"echo_level" : 0,
"analysis_type" : "non_linear",
"time_integration_method" : "implicit",
"scheme_type" : "bossak",
"model_import_settings" : {
"input_type" : "mdpa",
"input_filename" : "test_mik_Structural"
},
"material_import_settings" : {
"materials_filename" : "StructuralMaterials.json"
},
"time_stepping" : {
"time_step" : 0.1
},
"line_search" : false,
"convergence_criterion" : "residual_criterion",
"displacement_relative_tolerance" : 0.0001,
"displacement_absolute_tolerance" : 1e-9,
"residual_relative_tolerance" : 1e-8,
"residual_absolute_tolerance" : 1e-10,
"max_iteration" : 20,
"problem_domain_sub_model_part_list" : ["Parts_Structure"],
"processes_sub_model_part_list" : ["DISPLACEMENT_FixedDisplacement","StructureInterface3D_StructureInterface"],
"rotation_dofs" : false
},
"fluid_solver_settings" : {
"model_part_name" : "FluidModelPart",
"domain_size" : 3,
"solver_type" : "Monolithic",
"model_import_settings" : {
"input_type" : "mdpa",
"input_filename" : "test_mik_Fluid"
},
"echo_level" : 0,
"compute_reactions" : true,
"maximum_iterations" : 20,
"relative_velocity_tolerance" : 1e-8,
"absolute_velocity_tolerance" : 1e-10,
"relative_pressure_tolerance" : 1e-8,
"absolute_pressure_tolerance" : 1e-10,
"volume_model_part_name" : 0,
"skin_parts" : [0,"Slip3D"],
"no_skin_parts" : [0],
"time_stepping" : {
"automatic_time_step" : false,
"time_step" : 0.1
},
"formulation" : {
"element_type" : "vms",
"use_orthogonal_subscales" : false,
"dynamic_tau" : 1.0
}
},
"mesh_solver_settings" : {
"echo_level" : 0,
"domain_size" : 3,
"model_part_name" : "FluidModelPart",
"solver_type" : "structural_similarity"
},
"coupling_settings" : {
"nl_tol" : 1e-8,
"nl_max_it" : 25,
"solve_mesh_at_each_iteration" : true,
"mapper_settings" : [{
"mapper_face" : "unique",
"fluid_interface_submodelpart_name" : 0,
"structure_interface_submodelpart_name" : "StructureInterface3D_StructureInterface"
}],
"coupling_strategy_settings" : {
"solver_type" : "MVQN_recursive",
"w_0" : 0.825,
"buffer_size" : 7
},
"structure_interfaces_list" : ["StructureInterface3D_StructureInterface"],
"fluid_interfaces_list" : [0]
}
},
"processes" : {
"fluid_initial_conditions_process_list" : [],
"fluid_boundary_conditions_process_list" : [{
"python_module" : "apply_inlet_process",
"kratos_module" : "KratosMultiphysics.FluidDynamicsApplication",
"Parameters" : {
"model_part_name" : "FluidModelPart.0",
"variable_name" : "VELOCITY",
"modulus" : "0.1214(1-cos(0.1pit))y(1-y) if t<10 else 0.2428y*(1-y)",
"direction" : "automatic_inwards_normal",
"interval" : [0.0,"End"]
}
},{
"python_module" : "apply_outlet_process",
"kratos_module" : "KratosMultiphysics.FluidDynamicsApplication",
"Parameters" : {
"model_part_name" : "FluidModelPart.0",
"variable_name" : "PRESSURE",
"constrained" : true,
"value" : 0.0,
"hydrostatic_outlet" : false,
"h_top" : 0.0
}
},{
"python_module" : "apply_noslip_process",
"kratos_module" : "KratosMultiphysics.FluidDynamicsApplication",
"Parameters" : {
"model_part_name" : "FluidModelPart.0"
}
},{
"python_module" : "assign_vector_variable_process",
"kratos_module" : "KratosMultiphysics",
"Parameters" : {
"model_part_name" : "FluidModelPart.0",
"variable_name" : "MESH_DISPLACEMENT",
"constrained" : [true,true,true],
"value" : [0.0,0.0,0.0],
"interval" : [0.0,"End"]
}
},{
"python_module" : "assign_vector_variable_process",
"kratos_module" : "KratosMultiphysics",
"Parameters" : {
"model_part_name" : "FluidModelPart.0",
"variable_name" : "MESH_DISPLACEMENT",
"constrained" : [false,false,true],
"value" : [0.0,0.0,0.0],
"interval" : [0.0,"End"]
}
},{
"python_module" : "python_process",
"kratos_module" : "KratosMultiphysics",
"Parameters" : {
"model_part_name" : "FluidModelPart.0"
}
},{
"python_module" : "apply_slip_process",
"kratos_module" : "KratosMultiphysics.FluidDynamicsApplication",
"process_name" : "ApplySlipProcess",
"Parameters" : {
"model_part_name" : "FluidModelPart.Slip3D"
}
}],
"fluid_gravity" : [{
"python_module" : "assign_vector_by_direction_process",
"kratos_module" : "KratosMultiphysics",
"process_name" : "AssignVectorByDirectionProcess",
"Parameters" : {
"model_part_name" : "FluidModelPart.0",
"variable_name" : "BODY_FORCE",
"modulus" : 0.0,
"constrained" : false,
"direction" : [0.0,-1.0,0.0]
}
}],
"fluid_auxiliar_process_list" : [],
"structure_constraints_process_list" : [{
"python_module" : "assign_vector_variable_process",
"kratos_module" : "KratosMultiphysics",
"Parameters" : {
"model_part_name" : "Structure.DISPLACEMENT_FixedDisplacement",
"variable_name" : "DISPLACEMENT",
"constrained" : [true,true,true],
"value" : [0.0,0.0,0.0],
"interval" : [0.0,"End"]
}
}],
"structure_loads_process_list" : [{
"python_module" : "python_process",
"kratos_module" : "KratosMultiphysics",
"Parameters" : {
"model_part_name" : "Structure.StructureInterface3D_StructureInterface"
}
}]
},
"output_processes" : {
"gid_output" : [{
"python_module" : "gid_output_process",
"kratos_module" : "KratosMultiphysics",
"process_name" : "GiDOutputProcess",
"help" : "This process writes postprocessing files for GiD",
"Parameters" : {
"model_part_name" : "Structure.computing_domain",
"output_name" : "test_mik_structure",
"postprocess_parameters" : {
"result_file_configuration" : {
"gidpost_flags" : {
"GiDPostMode" : "GiD_PostBinary",
"WriteDeformedMeshFlag" : "WriteDeformed",
"WriteConditionsFlag" : "WriteConditions",
"MultiFileFlag" : "SingleFile"
},
"file_label" : "step",
"output_control_type" : "step",
"output_frequency" : 1,
"body_output" : true,
"node_output" : false,
"skin_output" : false,
"plane_output" : [],
"nodal_results" : ["DISPLACEMENT","REACTION","VELOCITY","ACCELERATION"],
"gauss_point_results" : ["VON_MISES_STRESS"]
},
"point_data_configuration" : []
}
}
},{
"python_module" : "gid_output_process",
"kratos_module" : "KratosMultiphysics",
"process_name" : "GiDOutputProcess",
"help" : "This process writes postprocessing files for GiD",
"Parameters" : {
"model_part_name" : "FluidModelPart.fluid_computational_model_part",
"output_name" : "test_mik_fluid",
"postprocess_parameters" : {
"result_file_configuration" : {
"gidpost_flags" : {
"GiDPostMode" : "GiD_PostBinary",
"WriteDeformedMeshFlag" : "WriteDeformed",
"WriteConditionsFlag" : "WriteConditions",
"MultiFileFlag" : "SingleFile"
},
"file_label" : "time",
"output_control_type" : "step",
"output_frequency" : 1,
"body_output" : true,
"node_output" : false,
"skin_output" : false,
"plane_output" : [],
"nodal_results" : ["VELOCITY","PRESSURE","MESH_DISPLACEMENT"],
"gauss_point_results" : []
},
"point_data_configuration" : []
}
}
}]
}
}

I see the problem "[0]" where the fluid interface should be ...

But GiD should write it there according to the input of the mok example, right?

[rubenzorrilla]

From the image I guess that you used the predefined 3D example in the GiD GUI. Can you confirm this? (I think there's a problem with the model part naming in the tcl script that generates the case).

[SamiBidier]

yes i can confirm that I onlz opened the example, meshed it and tried to calculate it. I simply wanted to re-start from that example, as I ran into the problem with my fluid/solid interface

[rubenzorrilla]

yes i can confirm that I onlz opened the example, meshed it and tried to calculate it. I simply wanted to re-start from that example, as I ran into the problem with my fluid/solid interface

OK. I'll try to reproduce the error. I'll let you know as soon as I have more information. Thanks for reporting @SamiBidier !

[rubenzorrilla]

I tried the predefined example in the GUI and there is no error in my case. Are you using the current master version of the GUI?

[SamiBidier]

Hi, I'm using the official GiD release version: GiD internal version: 15.0 ( 64 bits) with Kratos 7.0.2 edit: on windows
Would you suggest using the developer version? Maybe I'll try a re-installation.

[rubenzorrilla]

That Kratos release is way old... @jginternational is it possible to update the internet retrieve Kratos version for the GiD 15.0? @jginternational

[jginternational]

Sure @rubenzorrilla There is a newer release 7.1.5 https://github.com/KratosMultiphysics/GiDInterface/releases/tag/release-7.1.5

Also we can talk with @roigcarlo about a future release

[rubenzorrilla]

@SamiBidier would you mind trying the latest release @jginternational is pointing to? (should be as easy as changing the current kratos.gid folder by this one inside the problemtypes folder of your GiD installation directory.

[SamiBidier]

@rubenzorrilla Already done. Everything seems to work now. Thanks a lot for the quick support!

[rubenzorrilla]

Cool! Then, I'm closing the issue. Feel free to reopen it if necessary. Thanks!

[roigcarlo]

@jginternational Just jumping in to say that we released 8.0 on may. you can fetch it from here https://github.com/KratosMultiphysics/Kratos/tree/v8.0.1

Next release should fall during nov/dec, but everything seems to be a little delayed because covid, so I cannot guarantee a date until we speak about it.