Scalar dissipation rate and dissipative anomaly in isotropic turbulence

Mixing characteristics of an inhomogeneous scalar in isotropic and homogeneous sheared turbulence

Turbulent mixing of an inhomogeneous passive scalar field is studied in the context of a nonpremixed reacting flow. Direct numerical simulations of an initial steplike scalar field subjected to homogeneous sheared turbulence have been performed and the results compared with those of the case of decaying isotropic turbulence. For both flow conditions, the gradient of the conserved scalar tends t...

Simulation of Low Reynolds Number Isotropic Turbulence Including the Passive Scalar

Full simulations of homogeneous isotropic turbulence containing a homogeneous passive scalar were made at low Reynolds numbers and various Prandtl numbers. The results show that the spectral behavior of the two fields are quite similar; both fields decay as power-law functions of time. However. the decay exponent is quite dependent on both the Reynolds and Prandtl numbers. The decay exponent of...

Taylor ’ s dissipation surrogate and its associated anomaly

It is shown that, for stationary isotropic turbulence, Taylor’s well known dissipation surrogate Du/L can be derived directly from the Karman-Howarth equation and is in fact a surrogate for inertial transfer, which becomes equal to the dissipation, as the Reynolds number tends to infinity. The expression found for the dissipation rate ε is ε = A3u ′3 L [

Analysis of scalar dissipation in terms of vorticity geometry in isotropic turbulence

Compressibility effects on the scalar mixing in reacting homogeneous turbulence

The compressibility and heat of reaction influence on the scalar mixing in decaying isotropic turbulence and homogeneous shear flow are examined via data generated by direct numerical simulations (DNS). The reaction is modeled as one-step, exothermic, irreversible and Arrhenius type. For the shear flow simulations, the scalar dissipation rate, as well as the time scale ratio of mechanical to sc...