# Heat Transfer

Solve conduction-dominant heat transfer problems with convection and radiation occurring at boundaries

Address challenges with thermal management by analyzing the temperature distributions of components based on material properties, external heat sources, and internal heat generation for steady-state and transient problems.

A typical programmatic workflow for solving a heat transfer problem includes the following steps:

• Create a special thermal model container for a steady-state or transient thermal model.

• Define 2-D or 3-D geometry and mesh it.

• Assign thermal properties of the material, such as thermal conductivity k, specific heat c, and mass density ρ.

• Specify internal heat sources Q within the geometry.

• Specify temperatures on the boundaries or heat fluxes through the boundaries. For convective heat flux through the boundary $htc\left(T-{T}_{\infty }\right)$, specify the ambient temperature ${T}_{\infty }$ and the convective heat transfer coefficient htc. For radiative heat flux $\epsilon \sigma \left({T}^{4}-{T}_{\infty }{}^{4}\right)$, specify the ambient temperature ${T}_{\infty }$, emissivity ε, and Stefan-Boltzmann constant σ.

• Set an initial temperature or initial guess.

• Solve and plot results, such as the resulting temperatures, temperature gradients, heat fluxes, and heat rates.

## Functions

expand all

 `createpde` Create model `thermalProperties` Assign thermal properties of a material for a thermal model `internalHeatSource` Specify internal heat source for a thermal model `thermalBC` Specify boundary conditions for a thermal model `thermalIC` Set initial conditions or initial guess for a thermal model `solve` Solve heat transfer or structural analysis problem `assembleFEMatrices` Assemble finite element matrices
 `interpolateTemperature` Interpolate temperature in a thermal result at arbitrary spatial locations `evaluateTemperatureGradient` Evaluate temperature gradient of a thermal solution at arbitrary spatial locations `evaluateHeatFlux` Evaluate heat flux of a thermal solution at nodal or arbitrary spatial locations `evaluateHeatRate` Evaluate integrated heat flow rate normal to specified boundary `pdeplot` Plot solution or mesh for 2-D problem `pdeplot3D` Plot solution or surface mesh for 3-D problem `pdegplot` Plot PDE geometry `pdemesh` Plot PDE mesh
 `findThermalProperties` Find thermal material properties assigned to a geometric region `findHeatSource` Find heat source assigned to a geometric region `findThermalBC` Find thermal boundary conditions assigned to a geometric region `findThermalIC` Find thermal initial conditions assigned to a geometric region

## Objects

 `ThermalModel` Thermal model object `SteadyStateThermalResults` Steady-state thermal solution and derived quantities `TransientThermalResults` Transient thermal solution and derived quantities

## Properties

 ThermalMaterialAssignment Properties Thermal material properties assignments HeatSourceAssignment Properties Heat source assignments ThermalBC Properties Boundary condition for thermal model NodalThermalICs Properties Initial temperature at mesh nodes GeometricThermalICs Properties Initial temperature over a region or region boundary PDESolverOptions Properties Algorithm options for solvers

## Topics

### Thermal Analysis Workflow

Heat Transfer in Block with Cavity

Solve a heat equation that describes heat diffusion in a block with a rectangular cavity.

Heat Distribution in Circular Cylindrical Rod

Analyze a 3-D axisymmetric model by using a 2-D model.

Heat Conduction in Multidomain Geometry with Nonuniform Heat Flux

Perform a 3-D transient heat conduction analysis of a hollow sphere made of three different layers of material, subject to a nonuniform external heat flux.

Inhomogeneous Heat Equation on Square Domain

Solve the heat equation with a source term.

Heat Transfer Problem with Temperature-Dependent Properties

Solve the heat equation with a temperature-dependent thermal conductivity.

Thermal Analysis of Disc Brake

Use Partial Differential Equation Toolbox™ and Simscape™ Driveline™ to simulate a brake pad moving around a disc and analyze temperatures when braking.

### General PDE Workflow

Nonlinear Heat Transfer in Thin Plate

Perform a heat transfer analysis of a thin plate.