Articles you may be interested in Multifractal subgrid-scale modeling within a variational multiscale method for large-eddy simulation of passive-scalar mixing in turbulent flow at low and high Schmidt numbers The physics of energy transfer toward improved subgrid-scale models A hybrid subgrid-scale model constrained by Reynolds stress A dynamic subgrid-scale eddy viscosity model with a global ...

The atmospheric circulation response to the global warming–like tropical upper tropospheric heating is revisited using a dry atmospheric general circulation model (AGCM) in light of new diagnostics based on the concept of finite-amplitude wave activity (FAWA) on equivalent latitude. For a given tropical heating profile, the linear Wentzel–Kramers–Brillouin (WKB) wave refraction analysis sometim...

This study presents an alternative way to perform large eddy simulation based on a targeted numerical dissipation introduced by the discretization of the viscous term. It is shown that this regularisation technique is equivalent to the use of spectral vanishing viscosity. The flexibility of the method ensures high-order accuracy while controlling the level and spectral features of this purely n...

Understanding the physical mechanism maintaining fluid turbulence remains a fundamental theoretical problem. The two-layer model is an analytically and computationally simple system in which the dynamics of turbulence can be conveniently studied; in this work, a maximally simplified model of the statistically steady turbulent state in this system is constructed to isolate and identify the essen...

Field measurements are carried out to study statistical properties of the subgrid-scale (SGS) heat fluxes and SGS dissipation of temperature variance in the atmospheric surface layer, and to evaluate the ability of several SGS models to reproduce these properties. The models considered are the traditional eddy-diffusion model, the nonlinear (gradient) model, and a mixed model that is a linear c...

The feasibility of using an industrial compressible CFD code for large eddy simulations (LES) is evaluated. Dynamic subgrid scale (SGS) models developed at CTR have been implemented into the code and tested in a fully developed turbulent channel flow. In order to evaluate the effects of the SGS model compared with the numerical dissipation inherent in the upwind-biases schemes, computations wit...

Communicated by D.B. Spalding) A model equation for the scalar dissipation rate, based on the Two Scale Direct Interaction Approximation (TSDIA) of Yoshizawa [1J was solved and applied to a turbulent round jet in conjunction with turbulence modelling based on the eddy viscosity and diffusivity. The model coefficients were adjusted by using a similarity analysis for the round jet. This led to an...

the present article focuses on the evaluation of a first-moment closure model applicable to film cooling flow and heat transfer computations. the present first-moment closure model consists of a higher level of turbulent heat flux modeling in which two additional transport equations for temperature variance kθ and its dissipation rate εθ are considered. it not only employs a time scale that is ...

In this study a new formulation of the unsteady flamelet model is derived to account for the locally resolved distribution of the scalar dissipation rate obtained from large-eddy simulations (LES). Starting from the unsteady flamelet equations, a transformation leads to an Eulerian flamelet model, in which the scalar dissipation rate appears as function of time, space, and mixture fraction. In ...

The subgrid-scale (SGS) modeling of helical, isotropic turbulence in large eddy simulation is investigated by quantifying rates of helicity and energy cascade. Assuming Kolmogorov spectra, the Smagorinsky model with its traditional coefficient is shown to underestimate the helicity dissipation rate by about 40%. Several two-term helical models are proposed with the model coefficients calculated...