A Unified Formulation Of The Spectra Of Temperature-Fluctuations In Isotropic Turbulence

This paper gives a unified formulation of the spectra of temperature fluctuations in isotropic turbulence in all subregimes of wavenumbers. This is accomplished by making a systematic analysis of the effects of the fluid convection, viscosity and thermal diffusivity on the temperature spectrum. A generalized Heisenberg-von Weizsacker type model is used to describe the statistical interaction of the Fourier components of velocity and temperature. The latter is described in terms of kinetic energy and temperature variance transfer coefficients given by moments of the two spectra for large-wavenumber modes