LinearFVNormalVelocityFunctorDirichletBC

Description

LinearFVNormalVelocityFunctorDirichletBC specifies the normal velocity. This boundary condition is meant for the velocity variable(s) in the Navier-Stokes equations and is a good choice if you can assume the velocity is entirely parallel to the normal direction at the boundary. A positive value for the normal velocity denotes outflow; a negative value denotes inflow. We anticipate that this boundary condition will primarily be used on inflows since that is primarily where Dirichlet conditions for velocity are imposed.

Example Syntax

In this example a channel is rotated such that it would require some mental work from the user to predetermine the inlet velocity vector. It is much easier to instead prescribe the normal velocity directly and allow the boundary condition to partition the normal velocity among the normal components.

[LinearFVBCs<<<{"href": "../../syntax/LinearFVBCs/index.html"}>>>]
  [inlet-u]
    type = LinearFVNormalVelocityFunctorDirichletBC<<<{"description": "Adds a dirichlet BC for a velocity parallel to the normal direction. A positive dirichlet value would denote outflow, while negative denotes inflow.", "href": "LinearFVNormalVelocityFunctorDirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = 'left'
    variable<<<{"description": "The name of the variable that this boundary condition applies to"}>>> = vel_x
    normal_velocity<<<{"description": "The velocity in the normal direction"}>>> = '-1'
    component<<<{"description": "The velocity component this object is acting on. We will multiply the prescribed normal velocity by the corresponding face normal component"}>>> = 'x'
  []
  [inlet-v]
    type = LinearFVNormalVelocityFunctorDirichletBC<<<{"description": "Adds a dirichlet BC for a velocity parallel to the normal direction. A positive dirichlet value would denote outflow, while negative denotes inflow.", "href": "LinearFVNormalVelocityFunctorDirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = 'left'
    variable<<<{"description": "The name of the variable that this boundary condition applies to"}>>> = vel_y
    normal_velocity<<<{"description": "The velocity in the normal direction"}>>> = '-1'
    component<<<{"description": "The velocity component this object is acting on. We will multiply the prescribed normal velocity by the corresponding face normal component"}>>> = 'y'
  []
  [walls-u]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC<<<{"description": "Adds a dirichlet BC which can be used for the assembly of linear finite volume system and whose face values are determined using a functor. This kernel is only designed to work with advection-diffusion problems.", "href": "LinearFVAdvectionDiffusionFunctorDirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = 'top bottom'
    variable<<<{"description": "The name of the variable that this boundary condition applies to"}>>> = vel_x
    functor<<<{"description": "The functor for this boundary condition. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number."}>>> = 0.0
  []
  [walls-v]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC<<<{"description": "Adds a dirichlet BC which can be used for the assembly of linear finite volume system and whose face values are determined using a functor. This kernel is only designed to work with advection-diffusion problems.", "href": "LinearFVAdvectionDiffusionFunctorDirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = 'top bottom'
    variable<<<{"description": "The name of the variable that this boundary condition applies to"}>>> = vel_y
    functor<<<{"description": "The functor for this boundary condition. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number."}>>> = 0.0
  []
  [outlet_p]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC<<<{"description": "Adds a dirichlet BC which can be used for the assembly of linear finite volume system and whose face values are determined using a functor. This kernel is only designed to work with advection-diffusion problems.", "href": "LinearFVAdvectionDiffusionFunctorDirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = 'right'
    variable<<<{"description": "The name of the variable that this boundary condition applies to"}>>> = pressure
    functor<<<{"description": "The functor for this boundary condition. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number."}>>> = 0
  []
  [outlet_u]
    type = LinearFVAdvectionDiffusionOutflowBC<<<{"description": "Adds a boundary condition which represents a surface with outflowing material with a constant velocity. This kernel is only compatible with advection-diffusion problems.", "href": "LinearFVAdvectionDiffusionOutflowBC.html"}>>>
    variable<<<{"description": "The name of the variable that this boundary condition applies to"}>>> = vel_x
    use_two_term_expansion<<<{"description": "If an approximate linear expansion should be used to compute the face value."}>>> = false
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = right
  []
  [outlet_v]
    type = LinearFVAdvectionDiffusionOutflowBC<<<{"description": "Adds a boundary condition which represents a surface with outflowing material with a constant velocity. This kernel is only compatible with advection-diffusion problems.", "href": "LinearFVAdvectionDiffusionOutflowBC.html"}>>>
    variable<<<{"description": "The name of the variable that this boundary condition applies to"}>>> = vel_y
    use_two_term_expansion<<<{"description": "If an approximate linear expansion should be used to compute the face value."}>>> = false
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = right
  []
[]

Input Parameters

Input Files

• (modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/2d/rotated-channel.i)