# *************************************************************************** # * Copyright (c) 2023 Uwe Stöhr * # * * # * This file is part of the FreeCAD CAx development system. * # * * # * This program is free software; you can redistribute it and/or modify * # * it under the terms of the GNU Lesser General Public License (LGPL) * # * as published by the Free Software Foundation; either version 2 of * # * the License, or (at your option) any later version. * # * for detail see the LICENCE text file. * # * * # * This program is distributed in the hope that it will be useful, * # * but WITHOUT ANY WARRANTY; without even the implied warranty of * # * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * # * GNU Library General Public License for more details. * # * * # * You should have received a copy of the GNU Library General Public * # * License along with this program; if not, write to the Free Software * # * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * # * USA * # * * # *************************************************************************** import sys import FreeCAD from FreeCAD import Placement from FreeCAD import Rotation from FreeCAD import Vector import Draft import ObjectsFem from BOPTools import SplitFeatures from . import manager from .manager import get_meshname from .manager import init_doc def get_information(): return { "name": "Initial Flow - Elmer 2D", "meshtype": "solid", "meshelement": "Tet10", "constraints": [ "initial pressure", "initial temperature", "initial velocity", "temperature", "velocity", ], "solvers": ["elmer"], "material": "fluid", "equations": ["flow", "heat"], } def get_explanation(header=""): return ( header + """ To run the example from Python console use: from femexamples.equation_flow_initial_elmer_2D import setup setup() Flow and Heat equation with initial velocity - Elmer solver """ ) def setup(doc=None, solvertype="elmer"): # init FreeCAD document if doc is None: doc = init_doc() # explanation object # just keep the following line and change text string in get_explanation method manager.add_explanation_obj(doc, get_explanation(manager.get_header(get_information()))) # geometric objects # the wire defining the pipe volume in 2D p1 = Vector(400, -50.000, 0) p2 = Vector(400, -150.000, 0) p3 = Vector(1200, -150.000, 0) p4 = Vector(1200, 50.000, 0) p5 = Vector(0, 50.000, 0) p6 = Vector(0, -50.000, 0) wire = Draft.make_wire([p1, p2, p3, p4, p5, p6], closed=True) wire.MakeFace = True wire.Label = "Wire" # the circle defining the heating rod pCirc = Vector(160, 0, 0) axisCirc = Vector(1, 0, 0) placementCircle = Placement(pCirc, Rotation(axisCirc, 0)) circle = Draft.make_circle(10, placement=placementCircle) circle.MakeFace = True circle.Label = "HeatingRod" circle.ViewObject.Visibility = False # a link of the circle circleLink = doc.addObject("App::Link", "Link-HeatingRod") circleLink.LinkTransform = True circleLink.LinkedObject = circle # cut rod from wire to get volume of fluid cut = doc.addObject("Part::Cut", "Cut") cut.Base = wire cut.Tool = circleLink cut.ViewObject.Visibility = False # BooleanFregments object to combine cut with rod BooleanFragments = SplitFeatures.makeBooleanFragments(name="BooleanFragments") BooleanFragments.Objects = [cut, circle] # set view doc.recompute() if FreeCAD.GuiUp: BooleanFragments.ViewObject.Transparency = 50 BooleanFragments.ViewObject.Document.activeView().fitAll() # analysis analysis = ObjectsFem.makeAnalysis(doc, "Analysis") if FreeCAD.GuiUp: import FemGui FemGui.setActiveAnalysis(analysis) # solver if solvertype == "elmer": solver_obj = ObjectsFem.makeSolverElmer(doc, "SolverElmer") solver_obj.CoordinateSystem = "Cartesian 2D" equation_flow = ObjectsFem.makeEquationFlow(doc, solver_obj) equation_heat = ObjectsFem.makeEquationHeat(doc, solver_obj) else: FreeCAD.Console.PrintWarning( "Unknown or unsupported solver type: {}. " "No solver object was created.\n".format(solvertype) ) return doc analysis.addObject(solver_obj) # solver settings equation_flow.IdrsParameter = 3 equation_flow.LinearIterativeMethod = "Idrs" equation_flow.LinearPreconditioning = "ILU1" equation_flow.NonlinearIterations = 20 equation_flow.NonlinearNewtonAfterIterations = 20 equation_flow.RelaxationFactor = 0.15 equation_flow.Variable = "Flow Solution[Velocity:2 Pressure:1]" equation_heat.Convection = "Computed" equation_heat.IdrsParameter = 3 equation_heat.LinearIterativeMethod = "Idrs" equation_heat.LinearPreconditioning = "ILU1" equation_heat.NonlinearIterations = 20 equation_heat.NonlinearNewtonAfterIterations = 20 equation_heat.Priority = 5 equation_heat.RelaxationFactor = 0.15 equation_heat.Stabilize = True # material # fluid material_obj = ObjectsFem.makeMaterialFluid(doc, "Material_Fluid") mat = material_obj.Material mat["Name"] = "Carbon dioxide" mat["Density"] = "1.8393 kg/m^3" mat["DynamicViscosity"] = "14.7e-6 kg/m/s" mat["ThermalConductivity"] = "0.016242 W/m/K" mat["ThermalExpansionCoefficient"] = "0.00343 m/m/K" mat["SpecificHeat"] = "0.846 kJ/kg/K" material_obj.Material = mat material_obj.References = [(BooleanFragments, "Face2")] analysis.addObject(material_obj) # tube wall material_obj = ObjectsFem.makeMaterialSolid(doc, "Material_Wall") mat = material_obj.Material mat["Name"] = "Aluminum Generic" mat["Density"] = "2700 kg/m^3" mat["PoissonRatio"] = "0.35" mat["ShearModulus"] = "25.0 GPa" mat["UltimateTensileStrength"] = "310 MPa" mat["YoungsModulus"] = "70000 MPa" mat["ThermalConductivity"] = "237.0 W/m/K" mat["ThermalExpansionCoefficient"] = "23.1 µm/m/K" mat["SpecificHeat"] = "897.0 J/kg/K" material_obj.Material = mat material_obj.References = [(BooleanFragments, "Face1")] analysis.addObject(material_obj) # constraint inlet velocity FlowVelocity_Inlet = ObjectsFem.makeConstraintFlowVelocity(doc, "FlowVelocity_Inlet") FlowVelocity_Inlet.References = [(BooleanFragments, "Edge5")] FlowVelocity_Inlet.VelocityX = "20.0 mm/s" FlowVelocity_Inlet.VelocityXUnspecified = False analysis.addObject(FlowVelocity_Inlet) # constraint wall velocity FlowVelocity_Wall = ObjectsFem.makeConstraintFlowVelocity(doc, "FlowVelocity_Wall") FlowVelocity_Wall.References = [ (BooleanFragments, "Edge2"), (BooleanFragments, "Edge3"), (BooleanFragments, "Edge4"), (BooleanFragments, "Edge7"), ] FlowVelocity_Wall.VelocityXUnspecified = False FlowVelocity_Wall.VelocityYUnspecified = False analysis.addObject(FlowVelocity_Wall) # constraint initial velocity FlowVelocity_Initial = ObjectsFem.makeConstraintInitialFlowVelocity(doc, "FlowVelocity_Initial") FlowVelocity_Initial.References = [(BooleanFragments, "Face2")] FlowVelocity_Initial.VelocityX = "20.0 mm/s" FlowVelocity_Initial.VelocityY = "-20.0 mm/s" FlowVelocity_Initial.VelocityXUnspecified = False FlowVelocity_Initial.VelocityYUnspecified = False analysis.addObject(FlowVelocity_Initial) # constraint initial temperature Temperature_Initial = ObjectsFem.makeConstraintInitialTemperature(doc, "Temperature_Initial") Temperature_Initial.initialTemperature = 300.0 analysis.addObject(Temperature_Initial) # constraint wall temperature Temperature_Wall = ObjectsFem.makeConstraintTemperature(doc, "Temperature_Wall") Temperature_Wall.Temperature = 300.0 Temperature_Wall.NormalDirection = Vector(0, 0, -1) Temperature_Wall.References = [ (BooleanFragments, "Edge2"), (BooleanFragments, "Edge3"), (BooleanFragments, "Edge4"), (BooleanFragments, "Edge7"), ] analysis.addObject(Temperature_Wall) # constraint inlet temperature Temperature_Inlet = ObjectsFem.makeConstraintTemperature(doc, "Temperature_Inlet") Temperature_Inlet.Temperature = 300.0 Temperature_Inlet.NormalDirection = Vector(-1, 0, 0) Temperature_Inlet.References = [(BooleanFragments, "Edge5")] analysis.addObject(Temperature_Inlet) # constraint heating rod temperature Temperature_HeatingRod = ObjectsFem.makeConstraintTemperature(doc, "Temperature_HeatingRod") Temperature_HeatingRod.Temperature = 373.0 Temperature_HeatingRod.NormalDirection = Vector(0, -1, 0) Temperature_HeatingRod.References = [(BooleanFragments, "Edge1")] analysis.addObject(Temperature_HeatingRod) # constraint initial pressure Pressure_Initial = ObjectsFem.makeConstraintInitialPressure(doc, "Pressure_Initial") Pressure_Initial.Pressure = "100.0 kPa" Pressure_Initial.NormalDirection = Vector(0, -1, 0) Pressure_Initial.References = [(BooleanFragments, "Face2")] analysis.addObject(Pressure_Initial) # mesh femmesh_obj = analysis.addObject(ObjectsFem.makeMeshGmsh(doc, get_meshname()))[0] femmesh_obj.Shape = BooleanFragments femmesh_obj.ElementOrder = "1st" femmesh_obj.CharacteristicLengthMax = "4 mm" femmesh_obj.ViewObject.Visibility = False # mesh_region mesh_region = ObjectsFem.makeMeshRegion(doc, femmesh_obj, name="MeshRegion") mesh_region.CharacteristicLength = "2 mm" mesh_region.References = [ (BooleanFragments, "Edge1"), (BooleanFragments, "Vertex2"), (BooleanFragments, "Vertex4"), (BooleanFragments, "Vertex6"), ] mesh_region.ViewObject.Visibility = False # generate the mesh from femmesh import gmshtools gmsh_mesh = gmshtools.GmshTools(femmesh_obj, analysis) try: error = gmsh_mesh.create_mesh() except Exception: error = sys.exc_info()[1] FreeCAD.Console.PrintError(f"Unexpected error when creating mesh: {error}\n") doc.recompute() return doc