We use Navier–Stokes-based linear models for wall-bounded turbulent flows to estimate large-scale fluctuations at different wall-normal locations from their measurements a single location. In these models, we replace the nonlinear term by combination of stochastic forcing and an eddy dissipation term. The plays role in energy production large scales, small scales. Based on results channel flow,...

We develop a variationally consistent eddy viscosity model, given by [18] for convection diffusion equation, for the Navier-Stokes equations. We also prove that the new model is equivalent to a variational multiscale method. The new method removes the restriction that the fluctuations are quasi-stationary. We then give a complete error analysis. The error analysis is optimal and uniform in Reyn...

This paper deals with the development of efficient numerical solvers for the primitive equations of the ocean in turbulent regime. We derive the numerical approximation of a reduced model by the Smagorinsky turbulence model that includes stabilization of the pressure discretization by a penalty technique. We perform the numerical analysis of this discretization (stability, convergence, error es...

The deposition of particles in fully-developed turbulent channel flow has been calculated using large eddy simulation of the incompressible Navier-Stokes equations. Calculations were performed for Reynolds numbers of 11,160 and 79,400 (based on bulk velocity and hydraulic diameter); subgrid-scale stresses were parameterized using the dynamic eddy viscosity model. Particle motion was governed by...

In this study we investigate ultrafine particle (UFP) fluxes using a first order eddy viscosity turbulence closure Computational Fluid Dynamics (CFD) model and determine the different factors that influence emissions of UFP into the urban boundary layer. Both vertical turbulent fluxes as well as the fluxes due to mean circulatory flow are shown to contribute to the overall ventilation character...

The NASA Juncture Flow experiment is a new effort whose focus is attaining validation data in the juncture region of a wing-body configuration. The experiment is designed specifically for the purpose of CFD validation. Current turbulence models routinely employed by Reynolds-averaged Navier-Stokes CFD are inconsistent in their prediction of corner flow separation in aircraft juncture regions, s...

The paper addresses the Large-Eddy Simulation (LES) of the turbulent wake of the Ahmed car model. To this endwe use a Fourier-Chebyshevmulti-domain solver and the LES capability is implemented through the use of the Spectral Vanishing Viscosity (SVV) method, completed with a near-wall correction. A “pseudo-penalization” technique is used to model the bluff body. Comparisons of the present SVV-L...

Mathematical regularization of the nonlinear terms in the Navier-Stokes equations is found to provide a systematic approach to deriving subgrid closures for numerical simulations of turbulent flow. By construction, these subgrid closures imply existence and uniqueness of strong solutions to the corresponding modeled system of equations. We will consider the large-eddy interpretation of two such...

The filtered fluid dynamic equations are discretized in space by a high-order spectral difference(SD) method coupled with large eddy simulation (LES) approach. The subgrid-scale stress tensor is modelled by the wall-adapting local eddy-viscosity model (WALE). We solve the unsteady equations by advancing in time using a second-order backward difference formula (BDF2). The nonlinear algebraic sys...