filterByIndex

Access transient results for specified time steps

Since R2023b

Syntax

subsetR = filterByIndex(results,inds)

Description

subsetR = filterByIndex(results,inds) accesses transient results corresponding to the specified time steps.

Examples

Heat Distribution in Cylinder for Series of Time Steps

Analyze heat transfer in a cylinder.

Create an femodel object for solving a transient thermal problem, and assign a geometry representing a cylinder to the model.

model = femodel(AnalysisType="thermalTransient", ...
                Geometry=multicylinder(0.005,0.01));

Plot the geometry.

pdegplot(model,FaceLabels="on",FaceAlpha=0.5);

Assuming that the heat sink is made of copper, specify the thermal conductivity, mass density, and specific heat.

model.MaterialProperties = ...
    materialProperties(ThermalConductivity=400, ...
                       MassDensity=8960, ...
                       SpecificHeat=386);

Specify the Stefan-Boltzmann constant.

model.StefanBoltzmann = 5.670367e-8;

Apply the temperature boundary condition on the bottom surface of the cylinder.

model.FaceBC(1) = faceBC(Temperature=1000);

Specify the convection and radiation parameters on the top and side surfaces of the cylinder.

model.FaceLoad([2 3]) = faceLoad(ConvectionCoefficient=5, ...
                                 AmbientTemperature=300, ...
                                 Emissivity=0.8);

Set the initial temperature to the ambient temperature.

model.CellIC = cellIC(Temperature=300);

Generate a mesh.

model = generateMesh(model);

Solve the transient thermal problem at 0, 0.1, and 0.2 seconds.

results = solve(model,0:0.1:0.2);

Plot the temperature distribution for each time step. Access the results for each step by using the filterByIndex function.

for i = 1:length(results.SolutionTimes)
  figure
  resultsByStep = filterByIndex(results,i);
  pdeplot3D(results.Mesh,ColorMapData=resultsByStep.Temperature);
  clim([300 1000])
  title({['Time = ' num2str(results.SolutionTimes(i)) 's']})
end

Now, use the transient thermal results obtained for the second time step as the initial temperature of the cylinder.

R = filterByIndex(results,2);
model.CellIC = cellIC(Temperature=R);

Solve the transient thermal problem for the 10 time steps between 0.1 and 0.11 second.

results_01_011 = solve(model,linspace(0.1,0.11,10));

Input Arguments

results — Solution of structural or thermal problem

TransientStructuralResults object | TransientThermalResults object

Solution of a structural or thermal problem, specified as a TransientStructuralResults object or a TransientThermalResults object. Create results by using solve.

inds — Time steps

vector of positive integers

Time steps, specified as a vector of positive integers.

Output Arguments

subsetR — Solutions corresponding to specified time steps

TransientStructuralResults object | TransientThermalResults object

Solutions corresponding to specified time steps, returned as a TransientStructuralResults object or a TransientThermalResults object.

Version History

Introduced in R2023b