Here is the correct results using the new STL after fixing two more inconsitencies:
- Radiation problem should include temperature in K.
- All BCs on a particular set of faces need to be applied at once, otherwise the following assignment would overwrite the preceeding one if they are applied on the same set of faces.
code:
%% Model Setup for Heat Sink
thermalmodel = createpde('thermal','transient');
gm = importGeometry(thermalmodel,'heatsinkv2.stl');
pdegplot(thermalmodel,'FaceLabel','on','FaceAlpha',0.5);
axis equal
%% mesh
generateMesh(thermalmodel);
figure;
pdeplot3D(thermalmodel);
%% Boundary Condition, Aluminium Alloy Properties and Initial Conditions
TCval = @(location,state)139.3 + 0.204*(state.u-273.15); %sets thermal conductivity (W/m/°C) as a function of temperature only approximate equation based on linear trend for table data from ansys engineering alumnium alloy data
MDval = 2770; %density kg/m^3
SHval = 875; %specific heat (J/kg/°C)
ATval = 25+273.15; %ambient temperature
CCval = 30; %convective film coefficient W/m^2
REval = 0.77; %radiation emissivity
thermalmodel.StefanBoltzmannConstant = 5.670373E-8;
faces = [1,3:30];
thermalProperties(thermalmodel,'ThermalConductivity',TCval,'MassDensity',MDval,'SpecificHeat',SHval);
thermalBC(thermalmodel,'Face',faces,'ConvectionCoefficient',@(region,state)CCval,'Emissivity',@(region,state)REval,'AmbientTemperature',ATval);
thermalBC(thermalmodel,'Face',2,'ConvectionCoefficient',5,'Emissivity',0.1,'AmbientTemperature',ATval);
thermalIC(thermalmodel,60+273.15); %sets initial temperature °C problem with this as temp doesnt go down very fast?
%% solve
tlist= [0:10]; %time from 0 to 10seconds
thermalTransientResults = solve(thermalmodel,tlist);
pdeplot3D(thermalmodel,'ColorMapData',thermalTransientResults.Temperature(:,10)-273.15)
Regards,
Ravi
