∇

Properties

  • Wrapper around the fixedValue condition to set the static pressure from a definition of the total pressure
  • Applicable to the pressure field

Usage

The condition sets the static pressure at the patch \(p_p\) based on a specification of the total pressure, \(p_0\). The mode of operation is determined via the input entries and the dimensions of the convective flux, phi (\(\phi\)).

Subsonic incompressible

Patch pressure described by subtracting the dynamic pressure from the total pressure, where the flux has dimensions of \(m^3/s\).

\[p_p = p_0 - \frac{1}{2}\mag{\u}^2\]

Field file entries:

<patchName>
{
    type            totalPressure;
    rho             none;
    p0              uniform 0;
    value           uniform 0;

    // Optional entries
    U               U;
    phi             phi;
}

Subsonic compressible

Patch pressure described by subtracting the dynamic pressure from the total pressure, where the flux has dimensions of \(kg/s\).

\[p_p = p_0 - \frac{1}{2}\rho\mag{\u}^2\]

Field file entries:

<patchName>
{
    type            totalPressure;
    p0              uniform 100000;
    value           uniform 100000;

    // Optional entries
    U               U;
    phi             phi;
    rho             rho;
}

Transonic compressible

Ratio of specific heats, \(\gamma = C_p/C_v\) equal to 1.

\[p_p = \frac{p_0}{1 + \frac{1}{2} \psi \mag{\u}^2}\]

Field file entries:

<patchName>
{
    type            totalPressure;
    psi             psi;
    p0              uniform 100000;
    value           uniform 100000;

    // Optional entries
    U               U;
}

Supersonic compressible

Ratio of specific heats, \(\gamma = C_p/C_v\) greater than 1.

\[p_p = \frac{p_0}{\left(1 + \frac{\gamma - 1}{2} \psi \mag{\u}^2\right)^{\frac{\gamma}{\gamma - 1}}}\]

Field file entries:

<patchName>
{
    type            totalPressure;
    psi             psi;
    gamma           1.4;
    p0              uniform 100000;
    value           uniform 100000;

    // Optional entries
    U               U;
}

Further information

Source code: