Abstract
The vorticity evolution equation following from the Navier-Stokes equations for three-dimensional viscous incompressible fluid flows is represented in the divergent form. The partial derivative of the vorticity with respect to time is expressed as the divergence of a tensor called the vorticity transfer tensor. The concept of vorticity flux generated by a surface is defined. An expression for the pressure force in terms of the generated vorticity flux is obtained under the no-slip condition for three-dimensional bodies of constant and variable shape.