Scale-by-scale analysis of interscale scalar transfer in grid turbulence with mean scalar gradient

Large-scale anisotropy in scalar turbulence.

The effect of anisotropy on the statistics of a passive tracer transported by a turbulent flow is investigated. We show that under broad conditions an arbitrarily small amount of anisotropy propagates to the large scales where it eventually dominates the structure of the concentration field. This result is obtained analytically in the framework of an exactly solvable model and confirmed by nume...

Effect of Schmidt number on the velocity–scalar cospectrum in isotropic turbulence with a mean scalar gradient

We consider transport of a passive scalar by an isotropic turbulent velocity field in the presence of a mean scalar gradient. The velocity–scalar cospectrum measures the distribution of the mean scalar flux across scales. An inequality is shown to bound the magnitude of the cospectrum in terms of the shell-summed energy and scalar spectra. At high Schmidt number, this bound limits the possible ...

On the anisotropy of the turbulent passive scalar in the presence of a mean scalar gradient

We investigate the origin of the scalar gradient skewness in isotropic turbulence on which a mean scalar gradient is imposed. The problem of the advection of an anisotropic scalar field is reformulated in terms of the advection of an isotropic vector field. For this field triadic closure equations are derived. It is shown how the scaling of the scalar gradient skewness depends on the choice of ...

Two - scale scalar mesons in nuclei

We generalize the linear σ model in order to develop a chiral-invariant model of nuclear structure. The model is natural, and contains not only the usual σ meson which is the chiral partner of the pion but also a new chiral-singlet that is responsible for the medium-range nucleon-nucleon attraction. This approach provides significant advantages in terms of its description of nuclear matter and ...

A large-scale investigation of scalar implicature