fluid velocity

Module: fluid

Category: load

Type string: "fluid velocity"

Parameters

Name	Description	Default	Units
scale	scale	1	[]
velocity	velocity	{0,0,0}	[]

Description

In a fluid or fluid-FSI analysis, this boundary condition prescribes the fluid velocity vector relative to the mesh, \(\mathbf{w}\), on a named surface, simultaneously satisfying the natural boundary condition for \(w_{n}=\mathbf{w}\cdot\mathbf{n}\) and prescribing essential boundary conditions on the wx, wy and wz components of \(\mathbf{w}\) at the nodes of each facet, based on the value of \(\mathbf{n}\) at each node (obtained by averaging \(\mathbf{n}\) from adjoining facets).

<surface_load type="fluid velocity" surface="surface1">
  <scale lc="1">1.0</scale>
  <velocity>0,0,1</velocity>
</surface_load>

If a different vector value needs to be specified for each facet, use the following syntax,

<surface_load type="fluid velocity" surface="surface1">
  <scale lc="1">1.0</scale>
  <velocity surface_data="inlet"/>
</surface_load>

and provide the facet values in a user-defined SurfaceData map with name="inlet" and data_type="vec3".