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solidConductionSolver

Description

In the solidConduction solver, the temperature distribution is obtained from the solution of the heat diffusion or energy conservation equation.

Formulation

For an arbitrary body with volume V, bounded by a surface S with outward normal n, this equation can be expressed as:

\[ \begin{aligned} \int \rho c_p \frac{dT}{dt} dt = \int_S \vec{q''} \cdot \vec{n} dS + \int_V Q dV \end{aligned} \]

where:

  • \(\rho\) is density kg/m\(^3\)
  • \(c_p\) is the specific heat capacity in J/kg/K/
  • \(Q\) is the volumetric heat source in W/m\(^3\)
  • \(q''\) is the surface heat flux W/m\(^2\)

Using Fourier's law, one can express the heat flux in terms of the temperature gradient as:

\[ \begin{aligned} \vec{q''} = k \nabla T \end{aligned} \]

where \(k\) is thermal conductivity in W/m/k.

Thus, the final form of the equation (applying the Gauss-Green theorem) is:

\[ \begin{aligned} \int \rho c_p \frac{dT}{dt} dt = \int_V \nabla(k\nabla T) dV + \int_V Q dV \end{aligned} \]

Options

As a thermalSubSolver class, solidConduction requires the user to specify a few additional parameters in the thermalOptions sub-dictionary located within the solverDict.

Parameters in thermalOptions:

heatFluxSummary It activates the calculation of the heat flowing out from every surface of the domain, printing this information on the terminal. It is set to false by default.
calculateEnthalpy It activates the calculation of the enthalpy deposited in the fuel materials (useful for RIA cases). It is set to false by default.


Usage

Here is an example of the solverDict to be used for activating the solidConduction thermal solver:

thermalSolver solidConduction;

thermalOptions
{
    // Print summary of boundary-heat fluxes at each iteration
    heatFluxSummary false;

    // Activate calculation of enthalpy - false by default
    calculateEnthalpy false;
}