# *************************************************************************** # * Copyright (c) 2017 Markus Hovorka * # * Copyright (c) 2020 Bernd Hahnebach * # * Copyright (c) 2022 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 * # * * # *************************************************************************** __title__ = "FreeCAD FEM Heat Elmer writer" __author__ = "Markus Hovorka, Bernd Hahnebach, Uwe Stöhr" __url__ = "https://www.freecad.org" ## \addtogroup FEM # @{ import itertools import FreeCAD from .. import sifio from .. import writer as general_writer from femtools import membertools from femmesh import meshtools from . import heat class Heatwriter: def __init__(self, writer, solver): self.write = writer self.solver = solver def getHeatSolver(self, equation): # check if we need to update the equation self._updateHeatSolver(equation) # output the equation parameters s = self.write.createNonlinearSolver(equation) s["Equation"] = equation.Name s["Procedure"] = sifio.FileAttr("HeatSolve/HeatSolver") s["Bubbles"] = equation.Bubbles s["Exec Solver"] = "Always" s["Optimize Bandwidth"] = True s["Stabilize"] = equation.Stabilize s["Variable"] = self.write.getUniqueVarName("Temperature") return s def handleHeatConstants(self): self.write.constant( "Stefan Boltzmann", self.write.convert(self.write.constsdef["StefanBoltzmann"], "M/(O^4*T^3)"), ) def handleHeatEquation(self, bodies, equation): for b in bodies: if equation.Convection != "None": self.write.equation(b, "Convection", equation.Convection) if equation.PhaseChangeModel != "None": self.write.equation(b, "Phase Change Model", equation.PhaseChangeModel) def _updateHeatSolver(self, equation): # updates older Heat equations if not hasattr(equation, "Convection"): equation.addProperty( "App::PropertyEnumeration", "Convection", "Equation", "Type of convection to be used", ) equation.Convection = heat.CONVECTION_TYPE equation.Convection = "None" if not hasattr(equation, "PhaseChangeModel"): equation.addProperty( "App::PropertyEnumeration", "PhaseChangeModel", "Equation", "Model for phase change" ) equation.PhaseChangeModel = heat.PHASE_CHANGE_MODEL equation.PhaseChangeModel = "None" def handleHeatBndConditions(self): i = -1 for obj in self.write.getMember("Fem::ConstraintTemperature"): i = i + 1 femobjects = membertools.get_several_member( self.write.analysis, "Fem::ConstraintTemperature" ) femobjects[i]["Nodes"] = meshtools.get_femnodes_by_femobj_with_references( self.write.getSingleMember("Fem::FemMeshObject").FemMesh, femobjects[i] ) NumberOfNodes = len(femobjects[i]["Nodes"]) if obj.References: for name in obj.References[0][1]: if obj.ConstraintType == "Temperature": temperature = float(obj.Temperature.getValueAs("K")) self.write.boundary(name, "Temperature", temperature) elif obj.ConstraintType == "CFlux": flux = float(obj.CFlux.getValueAs("W")) # CFLUX is the flux per mesh node flux = flux / NumberOfNodes self.write.boundary(name, "Temperature Load", flux) self.write.handled(obj) for obj in self.write.getMember("Fem::ConstraintHeatflux"): if obj.References: for name in obj.References[0][1]: if obj.ConstraintType == "Convection": film = self.write.getFromUi(obj.FilmCoef, "W/(m^2*K)", "M/(T^3*O)") temp = self.write.getFromUi(obj.AmbientTemp, "K", "O") self.write.boundary(name, "Heat Transfer Coefficient", film) self.write.boundary(name, "External Temperature", temp) elif obj.ConstraintType == "DFlux": flux = self.write.getFromUi(obj.DFlux, "W/m^2", "M*T^-3") self.write.boundary(name, "Heat Flux BC", True) self.write.boundary(name, "Heat Flux", flux) self.write.handled(obj) def handleHeatInitial(self, bodies): tempObj = self.write.getSingleMember("Fem::ConstraintInitialTemperature") if tempObj is not None: refTemp = float(tempObj.initialTemperature.getValueAs("K")) for name in bodies: self.write.initial(name, "Temperature", refTemp) self.write.handled(tempObj) def _outputHeatBodyForce(self, obj, name): if obj.Mode == "Dissipation Rate": heatSource = obj.DissipationRate.getValueAs("W/kg").Value elif obj.Mode == "Total Power": ref = obj.References[0] ref_feat = ref[0] ref_sub_obj = ref[1][0] density = None for mat in self.write.getMember("App::MaterialObject"): mat_ref = [ *itertools.chain(*[itertools.product([i[0]], i[1]) for i in mat.References]) ] if (ref_feat, ref_sub_obj) in mat_ref: density = FreeCAD.Units.Quantity(mat.Material["Density"]) break if not density: # search material without references for mat in self.write.getMember("App::MaterialObject"): if not mat.References: density = FreeCAD.Units.Quantity(mat.Material["Density"]) break volume = ref_feat.getSubObject(ref_sub_obj).Volume heatSource = ( (obj.TotalPower / (density * FreeCAD.Units.Quantity(volume, "mm^3"))) .getValueAs("W/kg") .Value ) if heatSource == 0.0: # a zero heat would break Elmer (division by zero) raise general_writer.WriteError("The body heat source must not be zero!") self.write.bodyForce(name, "Heat Source", heatSource) def handleHeatBodyForces(self, bodies): bodyHeats = self.write.getMember("Fem::ConstraintBodyHeatSource") for obj in bodyHeats: if obj.References: for name in obj.References[0][1]: self._outputHeatBodyForce(obj, name) self.write.handled(obj) else: # if there is only one body heat without a reference # add it to all bodies if len(bodyHeats) == 1: for name in bodies: self._outputHeatBodyForce(obj, name) else: raise general_writer.WriteError( "Several body heat constraints found without reference to a body.\n" "Please set a body for each body heat constraint." ) self.write.handled(obj) def handleHeatMaterial(self, bodies): tempObj = self.write.getSingleMember("Fem::ConstraintInitialTemperature") if tempObj is not None: refTemp = float(tempObj.initialTemperature.getValueAs("K")) for name in bodies: self.write.material(name, "Reference Temperature", refTemp) for obj in self.write.getMember("App::MaterialObject"): m = obj.Material refs = obj.References[0][1] if obj.References else self.write.getAllBodies() for name in (n for n in refs if n in bodies): if "Density" not in m: raise general_writer.WriteError( "Used material does not specify the necessary 'Density'." ) self.write.material(name, "Name", m["Name"]) self.write.material(name, "Density", self.write.getDensity(m)) if "ThermalConductivity" not in m: raise general_writer.WriteError( "Used material does not specify the necessary 'Thermal Conductivity'." ) self.write.material( name, "Heat Conductivity", self.write.convert(m["ThermalConductivity"], "M*L/(T^3*O)"), ) if "SpecificHeat" not in m: raise general_writer.WriteError( "Used material does not specify the necessary 'Specific Heat'." ) self.write.material( name, "Heat Capacity", self.write.convert(m["SpecificHeat"], "L^2/(T^2*O)") ) ## @}