[KratosBio] - Adding Windkessel feature

applications/FluidDynamicsBiomedicalApplication/python_scripts/apply_windkessel_outlet_process.py

@@ -0,0 +1,118 @@
+import KratosMultiphysics
+
+import KratosMultiphysics.FluidDynamicsApplication as KratosFluid
+
+# Import applications
+import KratosMultiphysics.FluidDynamicsBiomedicalApplication as KratosBio
+
+
+def Factory(settings, Model):
+    if(type(settings) != KratosMultiphysics.Parameters):
+        raise Exception("expected input shall be a Parameters object, encapsulating a json string")
+    return ApplyWindkesselOutletProcess(Model, settings["Parameters"])
+
+
+class ApplyWindkesselOutletProcess(KratosMultiphysics.Process):
+    def __init__(self, Model, settings ):
+
+        KratosMultiphysics.Process.__init__(self)
+
+        default_settings = KratosMultiphysics.Parameters("""
+        {
+            "model_part_name"    : "",
+            "variable_name"      : "PRESSURE",
+            "constrained"        : true,
+            "value"              : 0.0,
+            "interval"           : [0.0,"End"],
+            "characteristic_resistance"        : 0.0,
+            "peripheral_resistance"        : 0.0,
+            "arterial_compliance"         : 0.0,
+            "venous_pressure"    : 0.0,
+            "initial_pressure"   : 0.0,
+            "pressure_unit"      : "mmHg",
+            "echo_level"         : 0
+        }
+        """)
+
+        # Trick: allows "value" to be a double, a string or a table value (otherwise the ValidateAndAssignDefaults might fail)
+        if(settings.Has("value")):
+            if(settings["value"].IsString()):
+                default_settings["value"].SetString("0.0")
+            elif settings["value"].IsNumber():
+                default_settings["value"].SetDouble(0.0)
+        else:
+            err_msg = "Provided settings have no 'value'. This needs to be provided."
+            raise Exception(err_msg)
+
+        settings.ValidateAndAssignDefaults(settings)
+
+        # Check the core processes input data
+        if (settings["model_part_name"].GetString() == ""):
+            raise Exception("Empty outlet pressure model part name. Set a valid model part name.")
+        elif (settings["variable_name"].GetString() != "PRESSURE"):
+            raise Exception("Outlet pressure settings variable_name is not PRESSURE.")
+        elif (settings["value"].IsString()):
+            if (settings["value"].GetString == ""):
+                raise Exception("Outlet pressure function sting is empty.")
+                raise Exception("Outlet external pressure function sting is empty.")
+
+        self.R1      = settings["characteristic_resistance"].GetDouble()
+        self.R2      = settings["peripheral_resistance"].GetDouble()
+        self.C       = settings["arterial_compliance"].GetDouble()
+        p0_mmHg      = settings["initial_pressure"].GetDouble()
+        pv_mmHg      = settings["venous_pressure"].GetDouble()
+        self.echo    = settings["echo_level"].GetInt()
+        self.pressure_unit = settings["pressure_unit"].GetString()
+
+        self.conv = 13.545*9.81 # Pressure conversion factor. It is used if pressure is provided in mmHg
+        if self.pressure_unit == "mmHg" :
+            self.pv = pv_mmHg*self.conv
+            p0 = p0_mmHg*self.conv
+        elif self.pressure_unit == "Pa" :
+            self.pv = pv_mmHg
+            p0      = p0_mmHg   # The pressure variable passed from the json file is given in Pa
+        else :
+            raise Exception("Pressure unit measyre can be given in mmHg or in Pa")
+
+        self.previous_q1 = 0.0
+        self.current_p1 = p0 # in Pa
+
+        # Set the OUTLET flag in the outlet model part nodes and conditions
+        self.outlet_model_part = Model[settings["model_part_name"].GetString()]
+        for node in self.outlet_model_part.Nodes:
+            node.Set(KratosMultiphysics.OUTLET, True)
+        for condition in self.outlet_model_part.Conditions:
+            condition.Set(KratosMultiphysics.OUTLET, True)
+
+    def ExecuteInitializeSolutionStep(self):
+
+        # Here the value to be provided to the outlet pressure is computed as the result of an ODE:
+        delta_t = self.outlet_model_part.ProcessInfo[KratosMultiphysics.DELTA_TIME]
+        t = self.outlet_model_part.ProcessInfo[KratosMultiphysics.TIME]
+
+        self.current_q1 = KratosFluid.FluidAuxiliaryUtilities.CalculateFlowRate(self.outlet_model_part)
+
+        self.modified_p1 = (1/self.C*(self.current_q1*( 1 + self.R1/self.R2) + self.R1*self.C*(self.current_q1 - self.previous_q1)/delta_t - (self.current_p1 - self.pv)/self.R2))*delta_t + self.current_p1
+
+        if self.echo > 0:
+            KratosMultiphysics.Logger.PrintInfo("Windkessel", f"Current flow rate: {self.current_q1}")
+            if self.pressure_unit == "mmHg" :
+                KratosMultiphysics.Logger.PrintInfo("Windkessel", f"Outlet new pressure: {self.modified_p1/self.conv} mmHg")
+            elif self.pressure_unit == "Pa" :
+                KratosMultiphysics.Logger.PrintInfo("Windkessel", f"Outlet new pressure: {self.modified_p1} Pa")
+            else :
+                raise Exception("Pressure unit measure can be given in mmHg or in Pa")
+
+        for node in self.outlet_model_part.Nodes:
+            # Setting new solution on the nodes
+            node.Fix(KratosMultiphysics.PRESSURE)
+            node.SetSolutionStepValue(KratosMultiphysics.PRESSURE,self.modified_p1)
+            node.SetSolutionStepValue(KratosMultiphysics.EXTERNAL_PRESSURE,self.modified_p1)
+
+    def ExecuteFinalizeSolutionStep(self):
+
+        self.previous_q1 = self.current_q1
+        self.current_p1 = self.modified_p1
+
+
+    # Private methods section

applications/FluidDynamicsBiomedicalApplication/tests/apply_windkessel_outlet_process_test.py

@@ -0,0 +1,108 @@
+import KratosMultiphysics
+import KratosMultiphysics.KratosUnittest as KratosUnittest
+import KratosMultiphysics.kratos_utilities as KratosUtilities
+from KratosMultiphysics.FluidDynamicsBiomedicalApplication import apply_windkessel_outlet_process
+
+class ApplyWindkesselOutletProcessTest(KratosUnittest.TestCase):
+    @classmethod
+    def __CreateModel(self):
+        model = KratosMultiphysics.Model()
+        outlet_model_part = model.CreateModelPart("OutletModelPart")
+        properties = outlet_model_part.CreateNewProperties(0)
+        outlet_model_part.ProcessInfo[KratosMultiphysics.DOMAIN_SIZE] = 2
+        outlet_model_part.ProcessInfo.SetValue(KratosMultiphysics.DELTA_TIME, 0.01)
+        outlet_model_part.AddNodalSolutionStepVariable(KratosMultiphysics.NORMAL)
+        outlet_model_part.AddNodalSolutionStepVariable(KratosMultiphysics.VELOCITY)
+        outlet_model_part.AddNodalSolutionStepVariable(KratosMultiphysics.PRESSURE)
+        outlet_model_part.AddNodalSolutionStepVariable(KratosMultiphysics.EXTERNAL_PRESSURE)
+        outlet_model_part.CreateNewNode(1, 0.0, 1.0, 0.0)
+        outlet_model_part.CreateNewNode(2, 2.0, 0.0, 0.0)
+        outlet_model_part.CreateNewCondition("LineCondition2D2N", 1, [1, 2], properties)
+        for node in outlet_model_part.Nodes:
+            node.AddDof(KratosMultiphysics.PRESSURE)
+            node.AddDof(KratosMultiphysics.VELOCITY_X)
+            node.AddDof(KratosMultiphysics.VELOCITY_Y)
+            node.AddDof(KratosMultiphysics.VELOCITY_Z)
+            node.SetSolutionStepValue(KratosMultiphysics.VELOCITY,[0.0,0.0,0.0])
+        return model
+
+    def testApplyWindkesselOutletProcessConversionFalse(self):
+        # Set up test - Check the behaviour of Windkessel update when values are written in Pa
+        model = self.__CreateModel()
+        settings = KratosMultiphysics.Parameters("""{
+            "Parameters" : {
+                "model_part_name"    : "OutletModelPart",
+                "variable_name"      : "PRESSURE",
+                "constrained"        : false,
+                "value"              : 0.0,
+                "interval"           : [0.0,"End"],
+                "characteristic_resistance"        : 0.02,
+                "peripheral_resistance"            : 0.98,
+                "arterial_compliance"              : 1.02,
+                "venous_pressure"    : 0.0,
+                "initial_pressure"   : 1.0,
+                "pressure_unit"      : "Pa",
+                "echo_level"         : 1
+            }
+        }""")
+
+
+        # Create the outlet process
+        outlet_process = apply_windkessel_outlet_process.ApplyWindkesselOutletProcess(model, settings["Parameters"])
+
+        # Execute and check the outlet process
+        self.__ExecuteAndCheckOutletProcessFalse(model, outlet_process)
+
+    def testApplyWindkesselOutletProcessConversionTrue(self):
+        # Set up test - Check the behaviour of Windkessel update when values are written in mmHg and converted in Pa
+        model = self.__CreateModel()
+        settings = KratosMultiphysics.Parameters("""{
+            "Parameters" : {
+                "model_part_name"    : "OutletModelPart",
+                "variable_name"      : "PRESSURE",
+                "constrained"        : false,
+                "value"              : 0.0,
+                "interval"           : [0.0,"End"],
+                "characteristic_resistance"        : 0.02,
+                "peripheral_resistance"            : 0.98,
+                "arterial_compliance"              : 1.02,
+                "venous_pressure"    : 0.0,
+                "initial_pressure"   : 1.0,
+                "pressure_unit"      : "mmHg",
+                "echo_level"         : 1
+            }
+        }""")
+
+
+        # Create the outlet process
+        outlet_process = apply_windkessel_outlet_process.ApplyWindkesselOutletProcess(model, settings["Parameters"])
+
+        # Execute and check the outlet process
+        self.__ExecuteAndCheckOutletProcessTrue(model, outlet_process)
+
+    def __ExecuteAndCheckOutletProcessFalse(self, model, outlet_process):
+        # Execute and check ExecuteInitializeSolutionStep
+        outlet_process.ExecuteInitializeSolutionStep()
+        outlet_process.ExecuteFinalizeSolutionStep()
+        for node in model.GetModelPart("OutletModelPart").Nodes:
+            self.assertTrue(node.Is(KratosMultiphysics.OUTLET))
+            self.assertTrue(node.IsFixed(KratosMultiphysics.PRESSURE))
+            self.assertAlmostEqual(node.GetSolutionStepValue(KratosMultiphysics.PRESSURE), 0.99,5)
+            self.assertAlmostEqual(node.GetSolutionStepValue(KratosMultiphysics.EXTERNAL_PRESSURE), 0.99,5)
+        for condition in model.GetModelPart("OutletModelPart").Conditions:
+            self.assertTrue(condition.Is(KratosMultiphysics.OUTLET))
+
+    def __ExecuteAndCheckOutletProcessTrue(self, model, outlet_process):
+        # Execute and check ExecuteInitializeSolutionStep
+        outlet_process.ExecuteInitializeSolutionStep()
+        outlet_process.ExecuteFinalizeSolutionStep()
+        for node in model.GetModelPart("OutletModelPart").Nodes:
+            self.assertTrue(node.Is(KratosMultiphysics.OUTLET))
+            self.assertTrue(node.IsFixed(KratosMultiphysics.PRESSURE))
+            self.assertAlmostEqual(node.GetSolutionStepValue(KratosMultiphysics.PRESSURE), 131.5472,1)
+            self.assertAlmostEqual(node.GetSolutionStepValue(KratosMultiphysics.EXTERNAL_PRESSURE), 131.5472,1)
+        for condition in model.GetModelPart("OutletModelPart").Conditions:
+            self.assertTrue(condition.Is(KratosMultiphysics.OUTLET))
+
+if __name__ == '__main__':
+    KratosUnittest.main()

applications/FluidDynamicsBiomedicalApplication/tests/test_FluidDynamicsBiomedicalApplication.py

@@ -11,6 +11,7 @@
 
 # Import the tests o test_classes to create the suites
 from apply_parabolic_inlet_process_test import ApplyParabolicInletProcessTest
+from apply_windkessel_outlet_process_test import ApplyWindkesselOutletProcessTest
 
 def AssembleTestSuites():
     ''' Populates the test suites to run.
@@ -29,6 +30,7 @@ def AssembleTestSuites():
     # Create a test suite with the selected tests (Small tests):
     smallSuite = suites['small']
     smallSuite.addTests(KratosUnittest.TestLoader().loadTestsFromTestCases([ApplyParabolicInletProcessTest]))
+    smallSuite.addTests(KratosUnittest.TestLoader().loadTestsFromTestCases([ApplyWindkesselOutletProcessTest]))
 
     # Create a test suite with the selected tests plus all small tests
     nightSuite = suites['nightly']