Minimum-dissipation scalar transport model for large-eddy simulation of turbulent flows

Abkar, Mahdi; Bae, H. Jane; Moin, Parviz

doi:10.1103/physrevfluids.1.041701

Cited by 60 publications

(65 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, the standard actuator-disk approach is employed to model the turbine-induced forces [23][24][25], and the subfilter turbulent fluxes are parametrized via the Lagrangian scale-dependent dynamic approach [26]. Detailed description of the numerical method of the LES framework can be found in [27][28][29][30][31][32][33].…”

Section: Les Governing Equationsmentioning

confidence: 99%

An Analytical Model for the Effect of Vertical Wind Veer on Wind Turbine Wakes

2018

Self Cite

View full text Add to dashboard Cite

Abstract:In this study, an analytical wake model for predicting the mean velocity field downstream of a wind turbine under veering incoming wind is systematically derived and validated. The new model, which is an extended version of the one introduced by Bastankhah and Porté-Agel, is based upon the application of mass conservation and momentum theorem and considering a skewed Gaussian distribution for the wake velocity deficit. Particularly, using a skewed (instead of axisymmetric) Gaussian shape allows accounting for the lateral shear in the incoming wind induced by the Coriolis force. This analytical wake model requires only the wake expansion rate as an input parameter to predict the mean wake flow downstream. The performance of the proposed model is assessed using the large-eddy simulation (LES) data of a full-scale wind turbine wake under the stably stratified condition. The results show that the proposed model is capable of predicting the skewed structure of the wake downwind of the turbine, and its prediction for the wake velocity deficit is in good agreement with the high-fidelity simulation data.

show abstract

Section: Les Governing Equationsmentioning

confidence: 99%

An Analytical Model for the Effect of Vertical Wind Veer on Wind Turbine Wakes

2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…If symplectic mid-point integration is applied in squareroot variables, then the continuity equation in the grid cell k is discretized as where the bar n+ 1 2 = ( n+1 + n )∕2 denotes averaging with equal weights to the time t n+ 1 2 . This can be expressed in conservative variables through multiplication by 2…”

Section: Conservative Time-integration Methodsmentioning

confidence: 99%

“…The test cases show that the amount of eddy viscosity needed in an LES method is dependent on the resolution of the grid. This information forms the basis for a new class of minimum-dissipation models: the QR model [96] and the anisotropic minimum dissipation model AMD [1,75]. The former has been developed for isotropic grids, whereas the latter is a generalization to anisotropic grids.…”

Section: Low-dissipation Large-eddy Simulation Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Low-Dissipation Simulation Methods and Models for Turbulent Subsonic Flow

Rozema

Verstappen

Veldman

et al. 2018

Arch Computat Methods Eng

View full text Add to dashboard Cite

The simulation of turbulent flows by means of computational fluid dynamics is highly challenging. The costs of an accurate direct numerical simulation (DNS) are usually too high, and engineers typically resort to cheaper coarse-grained models of the flow, such as large-eddy simulation (LES). To be suitable for the computation of turbulence, methods should not numerically dissipate the turbulent flow structures. Therefore, energy-conserving discretizations are investigated, which do not dissipate energy and are inherently stable because the discrete convective terms cannot spuriously generate kinetic energy. They have been known for incompressible flow, but the development of such methods for compressible flow is more recent. This paper will focus on the latter: LES and DNS for turbulent subsonic flow. A new theoretical framework for the analysis of energy conservation in compressible flow is proposed, in a mathematical notation of square-root variables, inner products, and differential operator symmetries. As a result, the discrete equations exactly conserve not only the primary variables (mass, momentum and energy), but also the convective terms preserve (secondary) discrete kinetic and internal energy. Numerical experiments confirm that simulations are stable without the addition of artificial dissipation. Next, minimum-dissipation eddyviscosity models are reviewed, which try to minimize the dissipation needed for preventing sub-grid scales from polluting the numerical solution. A new model suitable for anisotropic grids is proposed: the anisotropic minimum-dissipation model. This model appropriately switches off for laminar and transitional flow, and is consistent with the exact sub-filter tensor on anisotropic grids. The methods and models are first assessed on several academic test cases: channel flow, homogeneous decaying turbulence and the temporal mixing layer. As a practical application, accurate simulations of the transitional flow over a delta wing have been performed. The Compressible Navier-Stokes Equations Primary ConservationOur objective is the development of simulation methods for aerodynamic flow, governed by the Navier-Stokes equations for compressible flow [21]:

show abstract

“…Until that time, resort has to be sought to large-eddy turbulence models, again using as little eddy diffusion as possible. A modern example is the anisotropic minimum dissipation model AMD [56,57].…”

Section: What Will the Future Bring?mentioning

confidence: 99%

Entrainment and boundary-layer separation: a modeling history

Veldman

2017

J Eng Math

View full text Add to dashboard Cite

For many decades since Prandtl's presentation of the boundary-layer equations, all attempts to calculate separated boundary layers ended up in a break-down of the numerical algorithm. It was not until the late 1970s that the first successful calculations were reported. The paper describes the history and philosophy of the steps that led to understanding where the break-down originates and how to circumvent it. Especially, the role of Head's entrainment will be highlighted.

show abstract

Minimum-dissipation scalar transport model for large-eddy simulation of turbulent flows

Cited by 60 publications

References 34 publications

An Analytical Model for the Effect of Vertical Wind Veer on Wind Turbine Wakes

An Analytical Model for the Effect of Vertical Wind Veer on Wind Turbine Wakes

Low-Dissipation Simulation Methods and Models for Turbulent Subsonic Flow

Entrainment and boundary-layer separation: a modeling history

Contact Info

Product

Resources

About