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evaluateHeatRate

Evaluate integrated heat flow rate normal to specified boundary

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Syntax

Qn = evaluateHeatRate(thermalresults,RegionType,RegionID)

Description

Qn = evaluateHeatRate(thermalresults,RegionType,RegionID) returns the integrated heat flow rate normal to the boundary specified by RegionType and RegionID.

example

Examples

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Open Live Script

Compute the heat flow rate across a face of the block geometry.

Create an femodel object for steady-state thermal analysis and include a block geometry into the model.

model = femodel(AnalysisType="thermalSteady", ...
                Geometry="Block.stl");

Plot the geometry.

pdegplot(model.Geometry,FaceLabels="on",FaceAlpha=0.5)

Figure contains an axes object. The axes object contains 6 objects of type quiver, text, patch, line.

Specify the thermal conductivity of the block.

model.MaterialProperties = ...
    materialProperties(ThermalConductivity=80);

Apply constant temperatures on the opposite ends of the block. All other faces are insulated by default.

model.FaceBC(1) = faceBC(Temperature=100);
model.FaceBC(3) = faceBC(Temperature=50);

Generate a mesh.

model = generateMesh(model);

Solve the thermal problem.

R = solve(model);

Compute the heat flow rate across face 3 of the block.

Qn = evaluateHeatRate(R,Face=3)
Qn = 
4.0000e+04
Open Live Script

Compute the heat flow rate across the surface of the cooling sphere.

Create an femodel object for transient thermal analysis and include a unit sphere into the model.

model = femodel(AnalysisType="thermalTransient", ...
                Geometry=multisphere(1));

Generate a mesh.

model = generateMesh(model,GeometricOrder="linear");

Specify thermal properties of the sphere.

model.MaterialProperties = ...
    materialProperties(ThermalConductivity=80, ...
                       SpecificHeat=460, ...
                       MassDensity=7800);

Apply a convection boundary condition on the surface of the sphere.

model.FaceLoad(1) = ...
    faceLoad(ConvectionCoefficient=500,...
             AmbientTemperature=30);

Set the initial temperature.

model.CellIC = cellIC(Temperature=800);

Solve the thermal problem.

tlist = 0:100:2000;
R = solve(model,tlist);

Compute the heat flow rate across the surface of the sphere over time.

Qn = evaluateHeatRate(R,Face=1);
plot(tlist,Qn)
xlabel("Time")
ylabel("Heat Flow Rate")

Figure contains an axes object. The axes object with xlabel Time, ylabel Heat Flow Rate contains an object of type line.

Input Arguments

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Solution of a thermal problem, specified as a SteadyStateThermalResults object. Create thermalresults using the solve function.

Geometric region type, specified as Face for 3-D geometry or Edge for 2-D geometry.

Example: Qn = evaluateHeatRate(thermalresults,Face=3)

Data Types: char | string

Geometric region ID, specified as a positive integer. Find the region IDs using the pdegplot function with the FaceLabels (3-D) or EdgeLabels (2-D) value set to "on".

Example: Qn = evaluateHeatRate(thermalresults,Face=3)

Data Types: double

Output Arguments

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Heat flow rate, returned as a real number or, for time-dependent results, a vector of real numbers. This value represents the integrated heat flow rate, measured in energy per unit time, flowing in the direction normal to the boundary. Qn is positive if the heat flows out of the domain, and negative if the heat flows into the domain.

Version History

Introduced in R2017a

See Also

Objects

Functions