Generalization of the hydrodynamic analogy: Gradient flows

This paper deals with generalizing the Chilton-Colburn analogy to flows with a longitudinal pressure gradient. To this end, the concept of an effective velocity is introduced. The value of this velocity is determined from the boundary-layer momentum-balance equation using the friction factor for a flat plate and the average shear stress for the gradient flow. Cases of convective heat and mass transfer in laminar and turbulent flows of one-or two-phase media around bodies of various shapes are considered.