Velocity Source#

This subsection allows you to define velocity-dependent source terms. Two families of velocity source terms are supported. They enable the simulation of problems in a Lagrangian reference frame for which the Coriolis and centrifugal forces must be added or of problems including porous media.

Rotating Frame#

Rotating frame simulations use the following parameters:

subsection velocity source
  set rotating frame type    = none
  set omega_x                = 0
  set omega_y                = 0
  set omega_z                = 0
end

  • The rotating frame type parameter specifies the type of reference frame that is selected. The options are none for an Eulerian reference frame or srf for a single rotating frame. By selecting srf the additional contributions of the centrifugal force and Coriolis force induced by the rotating movement are taken into account in the Navier-Stokes equations.

  • The omega_x parameter is a double representing the \(x\) component of the angular velocity of the reference frame.

  • The omega_y parameter is a double representing the \(y\) component of the angular velocity of the reference frame.

  • The omega_z parameter is a double representing the \(z\) component of the angular velocity of the reference frame.

Darcy Penalization#

A Darcy-like source term can be added to the simulation using the following parameters:

subsection velocity source
  set Darcy type = none
end

  • The Darcy type parameter specifies the type of Darcy penalization term to be applied to the Navier-Stokes equations. The options are none or phase_change. The phase_change model uses the values of the Darcy penalty liquid and Darcy penalty solid set-up within the phase change subsection of the Physical Properties.

Caution

The phase change Darcy model does not currently have a Cahn-Hilliard implementation.