[FSI] Embedded membrane example

fluid_structure_interaction/README.md

@@ -5,6 +5,7 @@ Coming soon...
 
 ## Validation Cases
 - [FSI lid driven cavity](https://github.com/KratosMultiphysics/Examples/blob/master/fluid_structure_interaction/validation/fsi_lid_driven_cavity/README.md)
+- [Flexible membrane airfoil (embedded)](https://github.com/KratosMultiphysics/Examples/blob/master/fluid_structure_interaction/validation/embedded_fsi_membrane_airfoil/README.md)
 - [Mixer with flexible blades (embedded)](https://github.com/KratosMultiphysics/Examples/blob/master/fluid_structure_interaction/validation/embedded_fsi_mixer_Y/README.md)
 - [Mok benchmark](https://github.com/KratosMultiphysics/Examples/blob/master/fluid_structure_interaction/validation/fsi_mok/README.md)
 - [Mok benchmark (embedded)](https://github.com/KratosMultiphysics/Examples/blob/master/fluid_structure_interaction/validation/embedded_fsi_mok/README.md)

fluid_structure_interaction/validation/embedded_fsi_membrane_airfoil/README.md

@@ -0,0 +1,34 @@
+# Mixer with flexible blades
+
+**Author:** [Rubén Zorrilla](https://github.com/rubenzorrilla)
+
+**Kratos version:** 9.1
+
+**Source files:** [Mixer with flexible blades](https://github.com/KratosMultiphysics/Examples/tree/master/fluid_structure_interaction/validation/embedded_fsi_mixer_Y/source)
+
+## Case Specification
+This example is specifically conceived to prove the extended scope of applicatoin of embedded mesh methods. Hence, it involves extremely large rotations, which would be impossible to solve by using a body fitted ALE based approach.
+
+The problem is set up as a 2D idealization of a turbine mixer with clockwise-anticlockwise alternate rotation. The problem geometry is a unit diameter circle with three embedded flexible blades. An imposed rotation is enforced in the blades axis to emulate the spin of the rotor. Such rotation changes the direction (anticlockwise to clockwise and viceversa) after More details on the dimensions, material settings and boundary conditions can be found in [here](https://doi.org/10.1016/j.cma.2020.113179).
+
+## Results
+The fluid domain is meshed with a 45 and 540 radial and perimeter subdivisions Q1P1 elements centered structured mesh. Each one of the flexible blades is meshed with an 8x39 subdivisions structured mesh made with Total Lagrangian quadrilateral elements. The problem is run for 20s so three complete rotations (anticlockwise - clockwise - anticlockwise) are simulated.
+
+The obtained velocity and pressure fields, together with the level set zero isosurface representing the deformed geometry, are shown below.
+
+<p align="center">
+<figure>
+  <img src="data/embedded_fsi_mixer_Y_v.gif" alt="Velocity field and level set isosurface." style="width: 600px;"/>
+  <figcaption>Velocity field and level set isosurface.</figcaption>
+</figure>
+</p>
+
+<p align="center">
+<figure>
+  <img src="data/embedded_fsi_mixer_Y_p.gif" alt="Pressure field and level set isosurface." style="width: 600px;"/>
+  <figcaption>Pressure field and level set isosurface.</figcaption>
+</figure>
+</p>
+
+## References
+R. Zorrilla, R. Rossi, R. Wüchner and E. Oñate, An embedded Finite Element framework for the resolution of strongly coupled Fluid–Structure Interaction problems. Application to volumetric and membrane-like structures, Computer Methods in Applied Mechanics and Engineering (368), [10.1016/j.cma.2020.113179](https://doi.org/10.1016/j.cma.2020.113179)

fluid_structure_interaction/validation/embedded_fsi_membrane_airfoil/source/FluidMaterials.json

@@ -0,0 +1,20 @@
+{
+    "properties" : [{
+        "model_part_name" : "FluidModelPart",
+        "properties_id"   : 0,
+        "Material"        : null
+    },{
+        "model_part_name" : "FluidModelPart.FluidParts_Fluid",
+        "properties_id"   : 1,
+        "Material"        : {
+            "constitutive_law" : {
+                "name" : "Newtonian2DLaw"
+            },
+            "Variables"        : {
+                "DENSITY"           : 1.0,
+                "DYNAMIC_VISCOSITY" : 0.000155
+            },
+            "Tables"           : null
+        }
+    }]
+}

fluid_structure_interaction/validation/embedded_fsi_membrane_airfoil/source/MainKratos.py

@@ -0,0 +1,46 @@
+import sys
+import math
+import time
+import importlib
+
+import KratosMultiphysics
+
+def CreateAnalysisStageWithFlushInstance(cls, global_model, parameters):
+    class AnalysisStageWithFlush(cls):
+
+        def __init__(self, model,project_parameters, flush_frequency=10.0):
+            super().__init__(model,project_parameters)
+            self.flush_frequency = flush_frequency
+            self.last_flush = time.time()
+            sys.stdout.flush()
+
+        def Initialize(self):
+            super().Initialize()
+            sys.stdout.flush()
+
+        def FinalizeSolutionStep(self):
+            super().FinalizeSolutionStep()
+
+            if self.parallel_type == "OpenMP":
+                now = time.time()
+                if now - self.last_flush > self.flush_frequency:
+                    sys.stdout.flush()
+                    self.last_flush = now
+
+    return AnalysisStageWithFlush(global_model, parameters)
+
+if __name__ == "__main__":
+
+    with open("ProjectParameters.json", 'r') as parameter_file:
+        parameters = KratosMultiphysics.Parameters(parameter_file.read())
+
+    analysis_stage_module_name = parameters["analysis_stage"].GetString()
+    analysis_stage_class_name = analysis_stage_module_name.split('.')[-1]
+    analysis_stage_class_name = ''.join(x.title() for x in analysis_stage_class_name.split('_'))
+
+    analysis_stage_module = importlib.import_module(analysis_stage_module_name)
+    analysis_stage_class = getattr(analysis_stage_module, analysis_stage_class_name)
+
+    global_model = KratosMultiphysics.Model()
+    simulation = CreateAnalysisStageWithFlushInstance(analysis_stage_class, global_model, parameters)
+    simulation.Run()

fluid_structure_interaction/validation/embedded_fsi_membrane_airfoil/source/ProjectParameters.json

@@ -0,0 +1,276 @@
+ {
+    "analysis_stage" : "KratosMultiphysics.FSIApplication.fsi_analysis",
+    "problem_data": {
+        "problem_name": "embedded_fsi_membrane_airfoil",
+        "parallel_type": "OpenMP",
+        "echo_level": 0,
+        "start_time": 0.0,
+        "end_time": 1.0e0
+    },
+    "solver_settings": {
+        "solver_type": "partitioned_embedded",
+        "coupling_scheme": "dirichlet_neumann",
+        "echo_level": 1,
+        "structure_solver_settings": {
+            "solver_type"                        : "Dynamic",
+            "model_part_name"                    : "Structure",
+            "domain_size"                        : 2,
+            "echo_level"                         : 0,
+            "analysis_type"                      : "non_linear",
+            "time_integration_method"            : "implicit",
+            "scheme_type"                        : "bossak",
+            "model_import_settings"              : {
+                "input_type": "mdpa",
+                "input_filename": "embedded_fsi_membrane_airfoil_structure"
+            },
+            "material_import_settings": {
+                "materials_filename": "StructuralMaterials.json"
+            },
+            "time_stepping": {
+                "time_step": 5e-3
+            },
+            "line_search"                        : false,
+            "convergence_criterion"              : "residual_criterion",
+            "displacement_relative_tolerance"    : 1e-5,
+            "displacement_absolute_tolerance"    : 1e-7,
+            "residual_relative_tolerance"        : 1e-5,
+            "residual_absolute_tolerance"        : 1e-7,
+            "max_iteration"                      : 20
+        },
+        "fluid_solver_settings":{
+            "model_part_name"             : "FluidModelPart",
+            "domain_size"                 : 2,
+            "solver_type"                 : "Embedded",
+            "model_import_settings"       : {
+                "input_type"     : "mdpa",
+                "input_filename" : "embedded_fsi_membrane_airfoil_fluid"
+            },
+            "material_import_settings": {
+                "materials_filename": "FluidMaterials.json"
+            },
+            "distance_modification_settings": {
+                "distance_threshold": 1.0e-3
+            },
+            "echo_level"                  : 0,
+            "compute_reactions"           : true,
+            "maximum_iterations"          : 10,
+            "relative_velocity_tolerance" : 1e-5,
+            "absolute_velocity_tolerance" : 1e-7,
+            "relative_pressure_tolerance" : 1e-5,
+            "absolute_pressure_tolerance" : 1e-7,
+            "assign_neighbour_elements_to_conditions" : true,
+            "volume_model_part_name"      : "FluidModelPart.FluidParts_Fluid",
+            "skin_parts"                  : ["FluidModelPart.AutomaticInlet2D_Inlet","FluidModelPart.Outlet2D_Outlet","FluidModelPart.VelocityConstraints2D_Walls"],
+            "no_skin_parts"               : [],
+            "time_stepping"               : {
+                "automatic_time_step": false,
+                "time_step": 5e-3
+            },
+            "formulation": {
+                "element_type": "embedded_weakly_compressible_navier_stokes_discontinuous",
+                "is_slip": true,
+                "slip_length": 1.0e6,
+                "penalty_coefficient": 1.0e3,
+                "dynamic_tau": 1.0
+            },
+            "fm_ale_settings": {
+                "fm_ale_step_frequency": 1,
+                "mesh_movement": "implicit",
+                "fm_ale_solver_settings": {
+                    "structure_model_part_name": "FSICouplingInterfaceFluid",
+                    "virtual_model_part_name": "VirtualModelPart",
+                    "linear_solver_settings": {
+                        "preconditioner_type": "amg",
+                        "solver_type": "amgcl",
+                        "smoother_type": "ilu0",
+                        "krylov_type": "cg",
+                        "max_iteration": 2000,
+                        "verbosity": 0,
+                        "tolerance": 1e-8,
+                        "scaling": false,
+                        "use_block_matrices_if_possible": true
+                    },
+                    "embedded_nodal_variable_settings": {
+                        "gradient_penalty_coefficient": 5.0e-2,
+                        "linear_solver_settings": {
+                            "preconditioner_type": "amg",
+                            "solver_type": "amgcl",
+                            "smoother_type": "ilu0",
+                            "krylov_type": "cg",
+                            "max_iteration": 2000,
+                            "verbosity": 0,
+                            "tolerance": 1e-8,
+                            "scaling": false,
+                            "block_size": 1,
+                            "use_block_matrices_if_possible": true
+                        }
+                    }
+                }
+            }
+        },
+        "coupling_settings":{
+            "nl_tol": 1e-4,
+            "nl_max_it": 10,
+            "coupling_strategy_settings": {
+                "solver_type": "MVQN",
+                "w_0": 0.5,
+                "abs_cut_off_tol" : 1e-6
+            },
+            "structure_interfaces_list": ["Structure.LinePressure2D_Load"]
+        }
+	},
+    "processes":{
+        "structure_constraints_process_list" : [{
+            "python_module" : "assign_vector_variable_process",
+            "kratos_module" : "KratosMultiphysics",
+            "process_name"  : "AssignVectorVariableProcess",
+            "Parameters"    : {
+                "model_part_name" : "Structure.DISPLACEMENT_EndPoints",
+                "variable_name"   : "DISPLACEMENT",
+                "interval"        : [0.0,"End"],
+                "constrained"     : [true,true,true],
+                "value"           : [0.0,0.0,0.0]
+            }
+        }],
+        "structure_loads_process_list"       : [],
+        "fluid_initial_conditions_process_list"  : [],
+        "fluid_boundary_conditions_process_list" : [{
+            "python_module" : "apply_inlet_process",
+            "kratos_module" : "KratosMultiphysics.FluidDynamicsApplication",
+            "process_name"  : "ApplyInletProcess",
+            "Parameters"    : {
+                "model_part_name" : "FluidModelPart.AutomaticInlet2D_Inlet",
+                "variable_name"   : "VELOCITY",
+                "interval"        : [0.0,"End"],
+                "modulus"         : 2.5833,
+                "direction"       : "automatic_inwards_normal"
+            }
+        },{
+            "python_module" : "apply_outlet_process",
+            "kratos_module" : "KratosMultiphysics.FluidDynamicsApplication",
+            "process_name"  : "ApplyOutletProcess",
+            "Parameters"    : {
+                "model_part_name"    : "FluidModelPart.Outlet2D_Outlet",
+                "variable_name"      : "PRESSURE",
+                "constrained"        : true,
+                "value"              : 0.0,
+                "hydrostatic_outlet" : false,
+                "h_top"              : 0.0
+            }
+        },{
+            "python_module" : "assign_vector_variable_process",
+            "kratos_module" : "KratosMultiphysics",
+            "process_name"  : "AssignVectorVariableProcess",
+            "Parameters"    : {
+                "model_part_name" : "FluidModelPart.VelocityConstraints2D_Walls",
+                "variable_name"   : "VELOCITY",
+                "interval"        : [0.0,"End"],
+                "constrained"     : [false,true,false],
+                "value"           : [null,0.0,null]
+            }
+        },{
+            "python_module" : "assign_vector_variable_process",
+            "kratos_module" : "KratosMultiphysics",
+            "process_name"  : "AssignVectorVariableProcess",
+            "Parameters"    : {
+                "model_part_name" : "FluidModelPart.AutomaticInlet2D_Inlet",
+                "variable_name"   : "MESH_DISPLACEMENT",
+                "interval"        : [0.0,"End"],
+                "constrained"     : [true,true,false],
+                "value"           : [0.0,0.0,null]
+            }
+        },{
+            "python_module" : "assign_vector_variable_process",
+            "kratos_module" : "KratosMultiphysics",
+            "process_name"  : "AssignVectorVariableProcess",
+            "Parameters"    : {
+                "model_part_name" : "FluidModelPart.Outlet2D_Outlet",
+                "variable_name"   : "MESH_DISPLACEMENT",
+                "interval"        : [0.0,"End"],
+                "constrained"     : [true,true,false],
+                "value"           : [0.0,0.0,null]
+            }
+        },{
+            "python_module" : "assign_vector_variable_process",
+            "kratos_module" : "KratosMultiphysics",
+            "process_name"  : "AssignVectorVariableProcess",
+            "Parameters"    : {
+                "model_part_name" : "FluidModelPart.VelocityConstraints2D_Walls",
+                "variable_name"   : "MESH_DISPLACEMENT",
+                "interval"        : [0.0,"End"],
+                "constrained"     : [true,true,false],
+                "value"           : [0.0,0.0,null]
+            }
+        }],
+        "fluid_gravity" : [],
+        "fluid_auxiliar_process_list" : [{
+            "python_module": "apply_embedded_postprocess_process",
+            "kratos_module": "KratosMultiphysics.FluidDynamicsApplication",
+            "process_name": "ApplyEmbeddedPostprocessrocess",
+            "Parameters": {
+                "model_part_name": "FluidModelPart.FluidParts_Fluid"
+            }
+        }]
+    },
+    "output_processes":{
+        "gid_output" : [{
+            "python_module" : "gid_output_process",
+            "kratos_module" : "KratosMultiphysics",
+            "process_name"  : "GiDOutputProcess",
+            "Parameters"    : {
+                "model_part_name"        : "Structure",
+                "output_name"            : "gordnier_membrane_structure",
+                "postprocess_parameters" : {
+                    "result_file_configuration" : {
+                        "gidpost_flags"       : {
+                            "GiDPostMode"           : "GiD_PostBinary",
+                            "WriteDeformedMeshFlag" : "WriteDeformed",
+                            "WriteConditionsFlag"   : "WriteConditions",
+                            "MultiFileFlag"         : "SingleFile"
+                        },
+                        "file_label"          : "time",
+                        "output_control_type" : "step",
+                        "output_interval"     : 1,
+                        "body_output"         : true,
+                        "node_output"         : false,
+                        "skin_output"         : false,
+                        "plane_output"        : [],
+                        "nodal_results"       : ["DISPLACEMENT","VELOCITY","ACCELERATION","REACTION","LINE_LOAD"],
+                        "gauss_point_results" : []
+                    },
+                    "point_data_configuration"  : []
+                }
+            }
+        },{
+            "python_module": "gid_output_process",
+            "kratos_module": "KratosMultiphysics",
+            "process_name": "GiDOutputProcess",
+            "Parameters": {
+                "model_part_name": "FluidModelPart.FluidParts_Fluid",
+                "output_name": "gordnier_membrane_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_interval" : 1,
+                        "body_output": true,
+                        "node_output": false,
+                        "skin_output": false,
+                        "plane_output": [],
+                        "nodal_results": ["VELOCITY","PRESSURE","MESH_VELOCITY"],
+                        "nodal_nonhistorical_results": [],
+                        "elemental_conditional_flags_results": [],
+                        "gauss_point_results": []
+                    },
+                    "point_data_configuration": []
+                }
+            }
+        }]
+    }
+}