Prescribed Acceleration

The node adds a boundary condition, where the acceleration of the porous matrix is prescribed in one or more directions. With this boundary condition, it is possible to prescribe an acceleration in one direction, leaving the porous matrix free in the other directions. The condition can be added from the submenu and it can be combined with any of the conditions found in the submenu.

Coordinate System Selection


	Coordinate systems with directions which change with time should not be used.


	To define a porous, prescribed acceleration 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. Enter a value or expression for the prescribed acceleration ax, ay, and az (SI unit: m/s2).


	For 2D axisymmetric components and to define a porous, prescribed acceleration 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 the prescribed acceleration ar and az (SI unit: m/s2).


	Prescribed Acceleration Equations