Intermittency in free turbulent shear flows

A formalism previously used in the context of deformable porous media and turbulent/nonturbulent intermittent flows is restated here. The behavior of the intermittency function derivatives at the interface gives rise to surface integrals over the latter. The conditioned equations of continuity, momentum, energy, vorticity and conservation of a scalar are derived for the turbulent and irrotational zones. Surface integrals with a precise physical meaning enter the conditioned equations. They can be interpreted as entrainment of mass, momentum, energy and scalar, and as direct interactions between the turbulent and irrotational regions. Use is made of the experimental conditioned measurements for: (1) the plane wake behind a heated flat plate, and (2) the heated turbulent round jet; the profiles of entrainment of mass, and the combination of direct interactive force and entrainment of momentum are calculated. These derived profiles ar compared with models proposed by previous investigators.