ANISOTROPY OF THE DISPERSION TENSOR IN A TURBULENT BOUNDARY-LAYER

The second and third invariants of the Reynolds stress anisotropy tens or and the Reynolds stress dissipation rate anisotropy tensor have bee n evaluated from direct numerical simulation data for a boundary layer . The departure from isotropy increases in both inner and outer region s of the layer as the momentum thickness Reynolds number R(theta) decr eases. The relationship between the two anisotropy tensors has been ex amined in some detail. A linear relation, with a constant of proportio nality depending on the local turbulence Reynolds number, is well supp orted by the outer region data for three values of R(theta).