Prescribed Velocity
The Prescribed Velocity node adds a boundary condition where the velocity of the porous matrix is prescribed in one or more directions. With this boundary condition it is possible to prescribe a velocity in one direction, leaving the porous matrix free in the other directions. The condition can be added from the Porous Matrix Conditions submenu and it can be combined with any of the conditions found in the Fluid Conditions submenu.
Coordinate System Selection
Coordinate systems with directions which change with time should not be used.
Prescribed Velocity
To define a porous, prescribed velocity for each space direction (x, y, and z for 3D), select one or all of the Prescribed in x direction, Prescribed in y direction, and Prescribed in z direction check boxes. Then enter a value or expression for the components vx, vy, and vz (SI unit: m/s).
For 2D axisymmetric components and to define a prescribed velocity for each space direction (r and z), select one or both of the Prescribed in r direction and Prescribed in z direction check boxes. Then enter a value or expression for vr and vz (SI unit: m/s).
Prescribed Velocity Equations