Subgrid-scale Stress Research Articles

A-priori Direct Numerical Simulation assessment of models for generalized sub-grid scale turbulent kinetic energy in turbulent premixed flames

Abstract The fidelity of Large Eddy Simulation (LES) in the context of turbulent premixed combustion modelling depends on the complex coupling between turbulence and chemical reactions occurring at the unresolved scale. Although LES of combustion systems is becoming increasingly popular, the closures for sub-grid scale (SGS) stresses have mostly been derived assuming constant density flows. Similar to the unclosed scalar flux, the behaviour of the SGS stresses depends on the balance between heat release and turbulence, and it has been shown recently that counter-gradient transport (CGT) can occur for the stress tensor when the isotropic part of the stress tensor is not properly accounted for. This leads to a negative correlation between the predictions obtained from an eddy viscosity type model and the stresses obtained from Direct Numerical Simulation (DNS). In the present work the modelling of the isotropic part of the stress tensor, closely related to the generalised sub-grid scale kinetic energy, is considered in detail. To this end the interplay between SGS dilatation effects and unresolved velocity fluctuations is analysed using a-priori DNS analysis of turbulent, statistically planar flames with different values of global Lewis number and heat release parameter. Well-known models for generalised sub-grid scale kinetic energy have been assessed in the context of turbulent premixed combustion and detailed physical explanations for their behaviour have been provided. Further, the effects of SGS dilatation rate on the anisotropy of the SGS stresses have been highlighted using a variant of the Lumley triangle.

Searching for turbulence models by artificial neural network

Artificial neural network (ANN) is tested as a tool for finding a new subgrid model of the subgrid-scale (SGS) stress in large-eddy simulation. ANN is used to establish a functional relation between the grid-scale (GS) flow field and the SGS stress without any assumption of the form of function. Data required for training and test of ANN are provided by direct numerical simulation (DNS) of a turbulent channel flow. It is shown that ANN can establish a model similar to the gradient model. The correlation coefficients between the real SGS stress and the output of ANN are comparable to or larger than similarity models, but smaller than a two-parameter dynamic mixed model.

Subgrid-scale stresses and scalar fluxes constructed by the multi-scale turnover Lagrangian map

The multi-scale turnover Lagrangian map (MTLM) [C. Rosales and C. Meneveau, “Anomalous scaling and intermittency in three-dimensional synthetic turbulence,” Phys. Rev. E 78, 016313 (2008)] uses nested multi-scale Lagrangian advection of fluid particles to distort a Gaussian velocity field and, as a result, generate non-Gaussian synthetic velocity fields. Passive scalar fields can be generated with the procedure when the fluid particles carry a scalar property [C. Rosales, “Synthetic three-dimensional turbulent passive scalar fields via the minimal Lagrangian map,” Phys. Fluids 23, 075106 (2011)]. The synthetic fields have been shown to possess highly realistic statistics characterizing small scale intermittency, geometrical structures, and vortex dynamics. In this paper, we present a study of the synthetic fields using the filtering approach. This approach, which has not been pursued so far, provides insights on the potential applications of the synthetic fields in large eddy simulations and subgrid-scale (SGS) modelling. The MTLM method is first generalized to model scalar fields produced by an imposed linear mean profile. We then calculate the subgrid-scale stress, SGS scalar flux, SGS scalar variance, as well as related quantities from the synthetic fields. Comparison with direct numerical simulations (DNSs) shows that the synthetic fields reproduce the probability distributions of the SGS energy and scalar dissipation rather well. Related geometrical statistics also display close agreement with DNS results. The synthetic fields slightly under-estimate the mean SGS energy dissipation and slightly over-predict the mean SGS scalar variance dissipation. In general, the synthetic fields tend to slightly under-estimate the probability of large fluctuations for most quantities we have examined. Small scale anisotropy in the scalar field originated from the imposed mean gradient is captured. The sensitivity of the synthetic fields on the input spectra is assessed by using truncated spectra or model spectra as the input. Analyses show that most of the SGS statistics agree well with those from MTLM fields with DNS spectra as the input. For the mean SGS energy dissipation, some significant deviation is observed. However, it is shown that the deviation can be parametrized by the input energy spectrum, which demonstrates the robustness of the MTLM procedure.

An improved anisotropy-resolving subgrid-scale model for flows in laminar–turbulent transition region

Some types of mixed subgrid-scale (SGS) models combining an isotropic eddy-viscosity model and a scale-similarity model can be used to effectively improve the accuracy of large eddy simulation (LES) in predicting wall turbulence. Abe (2013) has recently proposed a stabilized mixed model that maintains its computational stability through a unique procedure that prevents the energy transfer between the grid-scale (GS) and SGS components induced by the scale-similarity term. At the same time, since this model can successfully predict the anisotropy of the SGS stress, the predictive performance, particularly at coarse grid resolutions, is remarkably improved in comparison with other mixed models. However, since the stabilized anisotropy-resolving SGS model includes a transport equation of the SGS turbulence energy, kSGS, containing a production term proportional to the square root of kSGS, its applicability to flows with both laminar and turbulent regions is not so high. This is because such a production term causes kSGS to self-reproduce. Consequently, the laminar–turbulent transition region predicted by this model depends on the inflow or initial condition of kSGS. To resolve these issues, in the present study, the mixed-timescale (MTS) SGS model proposed by Inagaki et al. (2005) is introduced into the stabilized mixed model as the isotropic eddy-viscosity part and the production term in the kSGS transport equation. In the MTS model, the SGS turbulence energy, kes, estimated by filtering the instantaneous flow field is used. Since the kes approaches zero by itself in the laminar flow region, the self-reproduction property brought about by using the conventional kSGS transport equation model is eliminated in this modified model. Therefore, this modification is expected to enhance the applicability of the model to flows with both laminar and turbulent regions. The model performance is tested in plane channel flows with different Reynolds numbers and in a backward-facing step flow. The results demonstrate that the proposed model successfully predicts a parabolic velocity profile under laminar flow conditions and reduces the dependence on the grid resolution to the same degree as the unmodified model by Abe (2013) for turbulent flow conditions. Moreover, it is shown that the present model is effective at transitional Reynolds numbers. Furthermore, the present model successfully provides accurate results for the backward-facing step flow with various grid resolutions. Thus, the proposed model is considered to be a refined anisotropy-resolving SGS model applicable to laminar, transitional, and turbulent flows.

Large eddy simulation of three-dimensional plane turbulent free jet flow

A detailed study of a three-dimensional spatially developing planar turbulent jet has been carried out by large eddy simulation (LES). The jet Reynolds number is 4000 based on the inlet velocity and jet width. The dynamic Smagorinsky model (DSM) is used to resolve the subgrid scale stress tensor. The transition from laminar to turbulent flow has been numerically identified and discussed in details. The evolution of vortex roll ups, their transportation and final disintegration to smaller vortices have been visualized by the plot of isosurface of Q criterion. The coherent structures in a turbulent planar jet have been well demonstrated. The time series plots of λ2 criterion shows the swirl and shear nature of the evolving vortices and their passage in the downstream. The time averaged velocity at far downstream (xD=10 and 15) shows a self-similarity behavior where the flow has established a fully turbulent nature. The energy spectra are shown to exhibit the −5/3 power law. The proper orthogonal decomposition (POD) shows that 90% of the fluctuating kinetic energy is contained within the first 100 modes. The probability density function on the centerline (yD=15 and zD=2.5) for different xD locations are plotted and the corresponding skewness and kurtosis values are reported for ū,v̄, w̄ and p̄.

Improving separated-flow predictions using an anisotropy-capturing subgrid-scale model

The major conclusion of this paper is that resolution requirements for large-eddy simulation (LES) of flow separation and reattachment can be significantly reduced using the anisotropy-capturing explicit algebraic subgrid-scale (SGS) stress model (EASSM) of Marstorp et al. (J. Fluid Mech., vol. 639, 2009, pp. 403–432), instead of the conventional isotropic dynamic eddy-viscosity model (DEVM). LES of flow separation in a channel with streamwise periodic hill-shaped constrictions and spanwise homogeneity is performed at coarse resolutions for which it is observed that flow separation cannot be predicted without a SGS model and cannot be correctly predicted by the DEVM, while reasonable predictions are obtained with the EASSM. It is shown that the lower resolution requirements by the EASSM, compared to the DEVM, is not only due its nonlinear formulation, but also due to the better formulation of its eddy-viscosity part. The improvements obtained with the EASSM have previously been demonstrated using higher-order numerical solvers for channel flows. In this study, it is observed that these improvements still remain using a low-order code with significant inherent numerical dissipation.

Large eddy simulation of spark ignition of a bluff-body stabilized burner using a subgrid-ignition model coupled with FGM-based combustion models

PurposeSafety improvement and pollutant reduction in many practical combustion systems and especially in aero-gas turbine engines require an adequate understanding of flame ignition and stabilization mechanisms. Improved software and hardware have opened up greater possibilities for translating basic knowledge and the results of experiments into better designs. The present study deals with the large eddy simulation (LES) of an ignition sequence in a conical shaped bluff-body stabilized burner involving a turbulent non-premixed flame. The purpose of this paper is to investigate the impact of spark location on ignition success. Particular attention is paid to the ease of handling of the numerical tool, the computational cost and the accuracy of the results.Design/methodology/approachThe discrete particle ignition kernel (DPIK) model is used to capture the ignition kernel dynamics in its early stage of growth after the breakdown period. The ignition model is coupled with two combustion models based on the mixture fraction-progress variable formulation. An infinitely fast chemistry assumption is first done, and the turbulent fluctuations of the progress variable are captured with a bimodal probability density function (PDF) in the line of the Bray–Moss–Libby (BML) model. Thereafter, a finite rate chemistry assumption is considered through the flamelet-generated manifold (FGM) method. In these two assumptions, the classical beta-PDF is used to model the temporal fluctuations of the mixture fraction in the turbulent flow. To model subgrid scale stresses and residual scalars fluxes, the wall-adapting local eddy (WALE) and the eddy diffusivity models are, respectively, used under the low-Mach number assumption.FindingsNumerical results of velocity and mixing fields, as well as the ignition sequences, are validated through a comparison with their experimental counterparts. It is found that by coupling the DPIK model with each of the two combustion models implemented in a LES-based solver, the ignition event is reasonably predicted with further improvements provided by the finite rate chemistry assumption. Finally, the spark locations most likely to lead to a complete ignition of the burner are found to be around the shear layer delimiting the central recirculation zone, owing to the presence of a mixture within flammability limits.Research limitations/implicationsSome discrepancies are found in the radial profiles of the radial velocity and consequently in those of the mixture fraction, owing to a mismatch of the radial velocity at the inlet section of the computational domain. Also, unlike FGM methods, the BML model predicts the overall ignition earlier than suggested by the experiment; this may be related to the overestimation of the reaction rate, especially in the zones such as flame holder wakes which feature high strain rate due to fuel-air mixing.Practical implicationsThis work is adding a contribution for ignition modeling, which is a crucial issue in various combustion systems and especially in aircraft engines. The exclusive use of a commercial computational fluid dynamics (CFD) code widely used by combustion system manufacturers allows a direct application of this simulation approach to other configurations while keeping computing costs at an affordable level.Originality/valueThis study provides a robust and simple way to address some ignition issues in various spark ignition-based engines, namely, the optimization of engines ignition with affordable computational costs. Based on the promising results obtained in the current work, it would be relevant to extend this simulation approach to spray combustion that is required for aircraft engines because of storage volume constraints. From this standpoint, the simulation approach formulated in the present work is useful to engineers interested in optimizing the engines ignition at the design stage.

A new LES model derived from generalized Navier–Stokes equations with nonlinear viscosity

Large Eddy Simulation (LES) is a very useful model for simulating turbulent flows (see Argyropoulos and Markatos, 2015, Guermond et al., 2004 or Sagaut, 2006, for example). One of the possible ways to derive the LES equations is to apply a filter operator to the Navier–Stokes equations, obtaining a new equation governing the behavior of the filtered velocity. This approach introduces the so called subgrid-scale stress tensor in the equations, that must be expressed in terms of the filtered velocity to close the problem. One of the most popular models is that proposed by Smagorinsky (1963), where the subgrid-scale stress tensor is modeled by introducing an eddy viscosity.In this work, we shall propose a new approximation to this problem by applying the filter, not to the Navier–Stokes equations, but to a generalized version of these equations with nonlinear viscosity. That is, we shall introduce a nonlinear viscosity, not as a procedure to close the subgrid-scale stress tensor, but as part of the model itself (see below). Consequently, we shall need a different method to close the subgrid-scale stress tensor, and we shall use the Clark approximation, where the Taylor expansion of the subgrid-scale stress tensor is computed (see Carati et al., 2001 and Vreman et al., 1966).

Large-eddy simulations of forced isotropic turbulence with viscoelastic fluids described by the FENE-P model

A new subgrid-scale (SGS) model developed for large-eddy simulations (LES) of dilute polymer solutions, described by the finitely extensible nonlinear elastic constitutive equation closed with the Peterlin approximation, is presented. In this distortion similarity model (DSIM) the filtered conformation tensor evolution equation is based on the self-similarity of the polymer stretching terms, and on a global equilibrium of the trace of the conformation tensor, which is proportional to the elastic energy stored in the polymer molecules, while the SGS stresses are modelled with the classical Smagorinsky model. The DSIM closure is assessed in direct numerical simulations (DNS) of forced isotropic turbulence using classical a priori tests, and in a posteriori (LES) showing very good agreement with all the exact (filtered DNS) results. The DSIM model is simple to implement and computationally inexpensive and represents a major step forward in the numerical simulation of turbulent flows of Newtonian fluids with polymer additives.

A simple and efficient implicit direct forcing immersed boundary model for simulations of complex flow

This paper presents an implementation of an implicit immersed boundary (IB) method in a flow solver based on the fractional step method and the finite volume method for complex flows involving moving boundaries and complex geometries. In this implementation, a body force caused by the immersed body is first introduced into the N-S equation to model the effect of immersed boundary. However, the body force is not pre-calculated, but implicitly determined in such a way that the velocity at the immersed boundary interpolated from the corrected velocity field accurately satisfies the no-slip and no-penetration conditions. Then, the large-eddy simulation is applied in the solver, where the subgrid-scale stress is determined by the Smagorinsky–Lilly model. Near the immersed boundaries, the subgrid-scale stress is determined by a wall model where the wall shear stress is directly calculated from the Lagrangian force(which represents the action of fluid on solid) on the immersed boundary. Such treatment makes the simulations of high Reynolds number turbulent flows feasible with the IB method. The accuracy and capability of the present method are demonstrated by simulations of a variety of both two- and three-dimensional simulations, including laminar flow past static and oscillating cylinders, rotating hydrofoil and turbulent flow around a three-dimensional circular cylinder and a sphere. It shows that the present implementation provides an easy-to-use, inexpensive and accurate technique for computational fluid dynamics in industrially relevant problems.

Dynamic modeling of the horizontal eddy viscosity coefficient for quasigeostrophic ocean circulation problems

This paper puts forth a simplified dynamic modeling strategy for the eddy viscosity coefficient parameterized in space and time. The eddy viscosity coefficient is dynamically adjusted to the local structure of the flow using two different nonlinear eddy viscosity functional forms to capture anisotropic dissipation mechanism, namely, (i) the Smagorinsky model using the local strain rate field, and (ii) the Leith model using the gradient of the vorticity field. The proposed models are applied to the one-layer and two-layer wind-driven quasigeostrophic ocean circulation problems, which are standard prototypes of more realistic ocean dynamics. Results show that both models capture the quasi-stationary ocean dynamics and provide the physical level of eddy viscosity distribution without using any a priori estimation. However, it is found that slightly less dissipative results can be obtained by using the dynamic Leith model. Two-layer numerical experiments also reveal that the proposed dynamic models automatically parameterize the subgrid-scale stress terms in each active layer. Furthermore, the proposed scale-aware models dynamically provide higher values of the eddy viscosity for smaller resolutions taking into account the local resolved flow information, and addressing the intimate relationship between the eddy viscosity coefficients and the numerical resolution employed by the quasigeostrophic models.

Experimental study and Large Eddy Simulation of thermal mixing phenomena of a parallel jet with perforated obstacles

Thermal mixing and flow field due to two parallel jets which have different temperatures are investigated both experimentally and numerically. The perforated passive obstacles are used with different geometrical specifications. They are located in front of the jets to control flow field and mixing behavior of the jets. An experimental setup designed and manufactured and Large Eddy Simulation turbulence model with the WALE subgrid-scale stress model were used to simulate same experimental conditions. Three perforated obstacles (POs) with different porosity values were used in the study and these obstacles inserted into a rectangular cross-section confined channel. Results demonstrated that increasing the values of temperature differences enhance thermal mixing performance along the channel. The best mixing quality was captured at the same flow rates of the jets. The perforated obstacle has significant positive effect on the mixing performance and this effect increase with higher porosity values. Dominant frequency of mixing region was found as 5 Hz in all cases. The temperature profiles showed that as porosity decreases thermal oscillations are starting to reach the wall. Both 2D and 3D velocity profiles demonstrated that using of POs reduces the domination of turbulence area in the channel.

On the topology of the eigenframe of the subgrid-scale stress tensor

In this paper, the geometrical properties of the subgrid-scale (SGS) stress tensor are investigated through its eigenvalues and eigenvectors. The concepts of Euler rotation angle and axis are utilized to investigate the relative rotation of the eigenframe of the SGS stress tensor with respect to that of the resolved strain rate tensor. Both Euler rotation angle and axis are natural invariants of the rotation matrix, which uniquely describe the topological relation between the eigenframes of these two tensors. Different from the reference frame fixed to a rigid body, the eigenframe of a tensor consists of three orthonormal eigenvectors, which by their nature are subjected to directional aliasing. In order to describe the geometric relationship between the SGS stress and resolved strain rate tensors, an effective method is proposed to uniquely determine the topology of the eigenframes. The proposed method has been used for testing three SGS stress models in the context of homogeneous isotropic turbulence at three Reynolds numbers, using both a priori and a posteriori approaches.

Scale-to-scale energy transfer in mixing flow induced by the Richtmyer-Meshkov instability.

The Richtmyer-Meshkov instability (RMI) mixing flow induced by a planar shock wave of Mach 1.6 is investigated using direct numerical simulation method. Interfacial perturbations of different scales between air and sulfur hexafluoride are introduced to study the effect of the initial conditions. Focus is placed on the analysis of the scale-to-scale transfer of kinetic energy in both Fourier and physical spaces. The kinetic energy injected from the perturbation scales is transferred to both larger and smaller scales in an average sense within the inner mixing zone (IMZ) at early times and is mainly passed down into smaller scales at the late stage. The physical-space energy flux due to the subgrid-scale (SGS) stress is studied using a filtering approach in order to shed light on the physical origin of the scale-to-scale kinetic energy transfer. It is found that the pointwise SGS energy flux is highly correlated with the local spike and bubble structures in the IMZ. Moreover, it turns out that the mean SGS energy flux is mainly ascribed to the component in the direction of shock wave propagation. An analysis using the method of conditional averaging manifests that the generation of local SGS energy flux is associated with the property of the surrounding flow induced by quadrupolar or dipolar vortex structures.

Mixing at high Schmidt number in a complex porous structure

Highly porous structures (porosity ≥75%), as metal foams or designed foam-like structures, are often used in industry to augment heat and mass transfer. In the present study, we focus on the mixing in highly porous structures in continuous millireactor characterized with a relatively low Reynolds number (ReD=240 – based on the ligament diameter and bulk velocity) and a high Schmidt number fluid (Sc=2400). We apply a combined numerical and experimental approach. The numerical simulations employ a Large Eddy Simulation (LES) method with dynamic Lagrangian approach for subgrid-scale turbulent stress and turbulent mass flux. The results of the numerical simulation are compared with our own combined Particle Imaging Velocimetry (PIV) and Laser Induced Fluorescence (LIF) measurements. The application of combined PIV/LIF makes it possible to simultaneously measure velocity components, turbulent stresses, concentration and concentration fluxes. The mechanism of the mixing is analyzed in detail with specific focus on validity of a simple gradient diffusion hypothesis (SGDH) in modeling of the turbulent mass transfer in complex porous structure.

Large Eddy Simulation Modeling of Non-Premixed Turbulent Oxy-Fuel Combustion Supplied by Three Separated Jets

ABSTRACTThe continuity of evolving pollutant emission regulations requires the design and the development of new burners. The separated-jets burner concept is an example that implies a careful understanding of the turbulent oxy-fuel flames properties developing in a furnace. Modeling, such as turbulent combustion, is a challenge, as it combines complex flow and transport phenomena with combustion events including a vast amount of species and reactions. The flamelet generated manifold (FGM) method is a promising technique to model reacting flows using a tabulated chemistry approach. It is considered as a function of the mixture fraction (Z) and a reaction progress variable (Y). In this work, the interaction of three aligned separated jets is numerically investigated. The central jet provides the natural gas and the others side jets provide the pure oxygen. Turbulence is modeled using the large eddy simulation model in which the dynamic Germano approach is applied to determinate the sub-grid scale stress. In the reacting case, the turbulence chemistry interaction is achieved by coupling the FGM tabulated chemistry within the computational fluid dynamic code. The numerical results show a good agreement with experimental data notably in the isothermal case. In the reacting case, statistical flow field quantities for velocity, mixture fraction, and temperature are analyzed in detail.

Grid and subgrid-scale interactions in viscoelastic turbulent flow and implications for modelling

ABSTRACTUsing direct numerical simulations of turbulent plane channel flow of homogeneous polymer solutions, described by the Finitely Extensible Nonlinear Elastic-Peterlin (FENE-P) rheological constitutive model, a-priori analyses of the filtered momentum and FENE-P constitutive equations are performed. The influence of the polymer additives on the subgrid-scale (SGS) energy is evaluated by comparing the Newtonian and the viscoelastic flows, and a severe suppression of SGS stresses and energy is observed in the viscoelastic flow. All the terms of the transport equation of the SGS kinetic energy for FENE-P fluids are analysed, and an approximated version of this equation for use in future large eddy simulation closures is suggested. The terms responsible for kinetic energy transfer between grid-scale (GS) and SGS energy (split into forward/backward energy transfer) are evaluated in the presence of polymers. It is observed that the probability and intensity of forward scatter events tend to decrease in the presence of polymers.

A priori and a posteriori evaluations of sub-grid scale models for the Burgers’ equation

Abstract In large eddy simulations (LES) of turbulent flows, large scale motions are resolved by the numerical simulation while the effect of the small scale motions is represented as sub-grid scale (SGS) stresses computed with SGS models. In the present study, we perform a priori and a posteriori evaluations of five SGS models for the one dimensional Burgers’ equation with the high-order flux reconstruction (FR) or correction procedure via reconstruction (CPR) approach. It is shown that all models, except the scale similarity model (SSM) and the mixed model (MM), demonstrate very little correlation with the DNS results. The stability of the SSM is investigated. The effects of numerical dissipation and the models’ influence on LES are discussed. Based on the present study, we advocate the use of implicit LES (ILES) in LES in the context of discontinuous high-order methods, or any numerical methods with built-in numerical dissipation.

Assessment of subgrid-scale stress statistics in non-premixed turbulent wall-jet flames

ABSTRACTWe investigate the heat-release effects on the characteristics of the subgrid-scale (SGS) stress tensor and SGS dissipation of kinetic energy and enstrophy. Direct numerical simulation data of a non-premixed reacting turbulent wall-jet flow with and without substantial heat release is employed for the analysis. This study comprises, among others, an analysis of the eigenvalues of the resolved strain rate and SGS stress tensors, to identify the heat-release effects on their topology. An assessment of the alignment between the eigenvectors corresponding to the largest eigenvalues of these two tensors is also given to provide further information for modelling of the SGS stress tensor. To find out the heat-release effects on the dynamics of the turbulent kinetic energy and enstrophy dissipation, probability density functions (PDFs) and mean values are analysed. The mean SGS shear stress and turbulent kinetic energy both slightly increase in the buffer layer and substantially decrease further away from the wall, due to the heat-release effects. Contrary to the kinetic energy, heat release decreases the mean SGS dissipation of enstrophy in the near-wall region. Moreover, differences in the shapes of the PDFs between the isothermal and exothermic cases indicate changes in the intermittency level of both SGS dissipations. Heat release also increases the SGS stress anisotropy in the near-wall region. Although, the structure of the mean resolved strain-rate tensor only marginally differs between the isothermal and exothermic cases in the near-wall region, substantial differences are observed in the jet area, where compressibility effects are important and heat-release effects are found to promote compression states. The differences in the relative alignment between the SGS stress and resolved strain-rate tensors in the isothermal and exothermic cases are discussed in connection with the differences in the SGS dissipation of kinetic energy.

Large-eddy simulations of an autorotating square flat plate

Large-eddy simulation (LES) turbulence models are underdeveloped in the area of fluid–structure interaction (FSI), specifically in autorotation applications. To gain a better understanding of FSI simulations, under the influence of strong turbulent interactions, several LES simulations were conducted to study the autorotation of a thin plate and compared to experimental measurements and RANS simulations found in literature. The plate is allowed to spin freely about its center of mass and is located near the center of a wind tunnel with a free stream velocity of 5 m/s. Wall effects from the wind tunnel enclosure are neglected. In this work, a coupled Computational Fluid Dynamics (CFD) – Rigid Body Dynamics (RBD) model is proposed employing the delayed-detached-eddy simulation (DDES) and the Smagorinsky turbulence models to resolve the subgrid-scale stress (SGS). The qualitative prediction of vortex structures and the qualitative computation of pressure coefficients are in good agreement with experimental results. When compared to RANS, the results from the LES models provide better predictions of the pressure coefficient. Moreover, LES accurately captures the transient behavior of the plate and close correspondence is found between the predicted and measured moment coefficient.