You can apply uniform or nonuniform (variable) pressure to faces for use in structural (static, frequency, buckling, nonlinear and dynamic) studies.

Uniform pressure is applied in the specified direction with uniform distribution to all selected faces. Pressure can be applied normal to the selected faces or it can be applied in some other direction. For example, hydrostatic pressure is normal to faces, while the snow on a sloped roof applies a vertical pressure and a wind blowing horizontally applies a horizontal pressure.

The equivalent force magnitude generated by pressure is equal to the pressure value times the area of the face. However, the net equivalent force depends on the geometry of the face and the direction of the pressure. For example, the reaction force resulting from applying a hydrostatic pressure on a full cylindrical face is zero due to symmetry.

Nonuniform pressure is described by a multiplier and a pressure distribution. The pressure distribution is described by the coefficients of a second-order polynomial in terms of a reference coordinate system.
The coordinate system should be oriented such that the distribution on the target face varies with respect to the x and y coordinates only.