# Wedge boundary condition¶

The wedge boundary condition defines an axis-symmetric boundary condition. The model and flow must be axis-symmetric along a central line such that all physical variables of the flow have same value and distribution at a radius and angle.

The axis-symmetric ‘wedge’ boundary is specified by two planes that must be selected on separate sides of the domain on surfaces running along the central line.

Important

In case of a 2-dimensional cylinder, the geometry is specified as a wedge of small angle (< 5 deg) and 1 cell thick.