Behavior of a solid rectangular parallelepiped in the 2D Couette and Poisseuille flows

On the basis of the thermodynamic approach, the expression is derived for the buoyant force acting on a body in the shape of a rectangular parallelepiped in the Couette and Poisseuille flows. The relation between the buoyant force and the density, shape, and orientation of the body and with its velocity relative to the medium is demonstrated.