The prediction and investigation of very high Reynolds number turbulent wall flows pose a significant challenge: experimental studies large eddy simulation (LES) are often inapplicable to these flows, Reynolds-averaged Navier–Stokes (RANS) methods fail characterize the essential flow characteristics, in particular, for separated flows. These facts explain need development hybrid RANS-LES methods. predominant approach deal with this question is combination RANS LES equation elements. This...

The development of hybrid RANS-LES methods is seen to be a very promising approach enable efficient simulations high Reynolds number turbulent flows involving flow separation. To contribute further advances, we present new, theoretically well based, dynamic method, referred as DLUM. It applied both attached and separated regimes: periodic hill simulated at 37 000. Its performance compared pure LES, RANS, other (given by DLUM modifications), experimental observations. shown that the use this...

Blade-resolved numerical simulations of wind energy applications using full blade and tower models are presented. The computational methodology combines solution technologies in a multi-mesh, multi-solver paradigm through dynamic overset framework. coupling finite volume solver high-order, hp-adaptive element is utilized. Additional including in-situ visualization atmospheric microscale modeling incorporated into the analysis environment. Validation framework performed on National Renewable...

In this work, we present Large Eddy Simulation (LES) results of atmospheric boundary layer (ABL) flow over complex terrain with neutral stratification using the OpenFOAM-based simulator for on/offshore wind farm applications (SOWFA). The complete work to investigate LES ABL real is described including meteorological-tower data analysis, mesh generation and case set-up. New conditions lateral top boundaries are developed validated allow inflow outflow as required in simulations. turbulent...

The first modeling results for Sandia flames D, E, and F using the flamelet generated manifold reduced chemistry model with a transported probability density function (TPDF) closure are presented. micro-mixing is modeled simple “interaction by exchange mean” mean molecular diffusion accounted through drift term. By accounting diffusion, stable burning could be predicted standard value mixing rate constant Cϕ=2. TPDF used in an priori analysis of main simplifying assumptions typically...

The Discontinuous Galerkin (DG) method provides numerical solutions of the NavierStokes equations with high order accuracy in complex geometries and allows for highly efficient parallelization algorithms. These attributes make DG attractive large eddy simulation (LES). main goal this work is to investigate feasibility adopting an explicit filter solution Navier-Stokes increase stability underresolved simulations such as LES use dynamic subgrid scale (SGS) models LES. takes advantage DG’s...

Abstract Many turbulent flow simulations require the use of hybrid methods because LES are computationally too expensive and RANS not sufficiently accurate. We consider a recently suggested RANS-LES model that has sound theoretical basis: it is systematically derived from realizable stochastic turbulence model. The applied to swirling nonswirling jet simulations. results shown be in very good agreement with available experimental data mildly flows. Compared commonly other methods, our does...

Large Eddy Simulation (LES) is computationally expensive at high Reynolds numbers (Re), especially for the accurate resolution of near-wall region in wall-bounded flows. Hence, hybrid turbulence models have been developed to reduce computational cost LES. In hybridmodeling approach, modeled using Reynolds-averaged Navier-Stokes (RANS) methods while regions away from wall are The most commonly used do not accurately predict mean streamwise velocity and normal stresses attached flows without...

Abstract Micro‐scale Reynolds‐averaged Navier‐Stokes (RANS) simulations of the neutral atmospheric boundary layer (ABL) over complex terrain and a comparison results with conditionally averaged met‐tower data are presented. A robust conditional sampling procedure for meteorological tower (met‐tower) to identify near‐neutral conditions based on criterion turbulence intensity is developed. The wind 14 met‐towers used model validation. ABL flow conducted which includes prominent hill using...

Studying swirling turbulent jet flows is important for both application-driven reasons and increasing our fundamental understanding of turbulence. Although experimental numerical studies provided some insights into the processes causing mixing enhancement momentum scalars, a definite still not achieved. The paper describes development combined RANS/LES method investigation structure flows. Comparisons with data provide evidence suitability this approach.

Large Eddy Simulation (LES) is computationally expensive at high Reynolds numbers (Re), especially for the accurate resolution of near-wall region in wall-bounded flows. Hence, hybrid turbulence models have been developed to reduce computational cost LES. In modeling approach, nearwall modeled using Reynolds-averaged Navier-Stokes (RANS) methods while regions away from wall are However, recently proposed cannot be seen as real unified models. there a need development which can used...

The paper reports the results of numerical investigations swirling turbulent jet flows by large eddy simulation (LES). Inflow data are provided on basis Reynolds-averaged Navier-Stokes (RANS) simulations. In particular, instantaneous inflow produced a forcing that generates correlated noise. this way, characteristic length and time scales inflowing eddies in consistency with corresponding RANS profiles imposed at inlet. performance several subgrid-scale stress models is studied. mechanism...