Finite element based large eddy simulation of flow over bluff bodies

Tran, Steven A.; Cummings, Reed; Sahni, Onkar

doi:10.1016/j.compfluid.2016.10.027

Cited by 11 publications

(12 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[8][9][10] The dynamic procedure is local in nature and is based on a localized version of the variational Germano identity. 8,9 In this local procedure, Lagrangian averaging along fluid pathtubes is applied to make it robust. Further, an arbitrary Lagrangian Eulerian (ALE) description is used to account for the deforming mesh due to the relative motion of the airfoil.…”

Section: Dynamic Large Eddy Simulationsmentioning

confidence: 99%

“…This was done in both a spectral code 20 and a finite element code. 8,9 The combined subgrid-scale model is defined as…”

Section: Iia Combined Model Formulationmentioning

confidence: 99%

“…To dynamically compute the Smagorinsky parameter in a local fashion, we follow the localized version of the variational Germano identity (VGI) developed by Tran et al 8,9 In this local procedure, Lagrangian averaging along fluid pathtubes is applied to make it robust. The dynamic local procedure and the associated approximations are summarized in this section.…”

Section: Iib Dynamic Proceduresmentioning

confidence: 99%

“…Current LES approach is based on the finite element (FE) method and uses a combined subgrid-scale model which employs the residual-based variational multiscale (RBVMS) model along with the dynamic Smagorinsky model. [8][9][10] The dynamic procedure is based on a localized version of the variational Germano identity (VGI). 8,9 An arbitrary Lagrangian Eulerian (ALE) description is used to account for the relative motion of the airfoil.…”

Section: Introductionmentioning

confidence: 99%

“…[8][9][10] The dynamic procedure is based on a localized version of the variational Germano identity (VGI). 8,9 An arbitrary Lagrangian Eulerian (ALE) description is used to account for the relative motion of the airfoil. 11 The ease with which the FE method can be applied on unstructured meshes makes it a useful option for investigating many challenging problems of interest.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Large Eddy Simulation of Surging Airfoils with Moderate to Large Streamwise Oscillations

Kocher

Cummings

Tran

et al. 2017

55th AIAA Aerospace Sciences Meeting

Self Cite

View full text Add to dashboard Cite

A large eddy simulation (LES) based numerical investigation is carried out for flow over two surging airfoils with moderate to large streamwise oscillations. In each case, the airfoil is subjected to a sinusoidal surging motion with streamwise oscillation at a fixed angle of attack. The amplitude of the sinusoidal oscillation is varied within a moderate range as well as in the high range. The amplitude of oscillation is characterized by the advance ratio, which is defined as the ratio of the maximum relative velocity in excess to the mean relative velocity (or mean free-stream velocity) to the mean relative velocity. The relative velocity is defined between the airfoil and ambient fluid. For the moderate range, NACA 0018 airfoil at a mean Reynolds number of 300,000 and 4 • angle of attack is considered. Two advance ratios of 0.34 and 0.51 are considered to match with the experiments of Strangfeld et al. 1 For the high range, NACA 0012 airfoil at a mean Reynolds number of 40,000 and 6 • angle of attack is considered at three advance ratios of 0.8, 1.0 and 1.2 to match with the experiments of Granlund et al. 2 Note that the highest advance ratio case involves the reversed flow condition, where in a part of the surging cycle the relative flow becomes negative or is from the geometric trailing end of the airfoil to the leading end. Lift force is compared between the experiments and simulations. Overall a good agreement is obtained for the lift force in all cases. Additionally, for all cases flowfields from simulations are examined at different phases of the surge cycle. For the moderate advance ratio cases, a similar flow pattern is observed between the two advance ratios and no distinct vortex is shed from the airfoil. On the other hand, in all three high advance ratio cases a distinct vortex is shed near the (geometric) leading edge on the suction or upper side. This prominent leading-edge vortex is shed as the minimum velocity is reached in the surging cycle and advects downstream (in the horizontal direction) by roughly the mean free-stream velocity. The relative position of the shed vortex (with respect to the airfoil) varies significantly between the three high advance ratio cases; it crosses the leading edge before sweeping over the airfoil in the case with the highest advance ratio of 1.2 (i.e., in the case with the reverse flow regime).

show abstract

Section: Dynamic Large Eddy Simulationsmentioning

confidence: 99%

“…This was done in both a spectral code 20 and a finite element code. 8,9 The combined subgrid-scale model is defined as…”

Section: Iia Combined Model Formulationmentioning

confidence: 99%

Section: Iib Dynamic Proceduresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Large Eddy Simulation of Surging Airfoils with Moderate to Large Streamwise Oscillations

Kocher

Cummings

Tran

et al. 2017

55th AIAA Aerospace Sciences Meeting

Self Cite

View full text Add to dashboard Cite

show abstract

A dynamic variational multiscale method on unstructured meshes for stationary transport problems

Sahni

2023

Numerical Methods in Fluids

Self Cite

View full text Add to dashboard Cite

Summary This paper presents a variational multiscale (VMS) based finite element method where the stabilization parameter is computed dynamically. The current dynamic procedure takes in a general structure/form of the stabilization parameter with unknown coefficients and computes them dynamically in a local fashion resulting in a dynamic VMS‐based finite element method. Thus, a static stabilization parameter with pre‐defined coefficients is not needed. A variational Germano identity (VGI) based local procedure suitable for unstructured meshes is developed to perform the dynamic computation in a local fashion. The local VGI based procedure is applied for each interior vertex in the mesh and unknown coefficients are first determined locally at each vertex, and subsequently, for each element a maximum value is taken over the vertices of the element. To make the current procedure practical, a coarser secondary solution is constructed from the primary coarse‐scale solution, which is done locally over a patch of elements around each interior vertex. Further, averaging steps are employed to make the local dynamic procedure robust. Currently, the new dynamic VMS formulation is applied to steady problems governed by the advection‐diffusion and incompressible Navier‐Stokes equations in both 1D and 2D to demonstrate its efficacy and effectiveness.

show abstract

Influence of Swirl Flow Pattern in Single Tube Burner on Turbulent Flame Blow-Off Limit

wahhab¹

2022

Lecture Notes in Mechanical Engineering

View full text Add to dashboard Cite

Finite element based large eddy simulation of flow over bluff bodies

Cited by 11 publications

References 40 publications

Large Eddy Simulation of Surging Airfoils with Moderate to Large Streamwise Oscillations

Large Eddy Simulation of Surging Airfoils with Moderate to Large Streamwise Oscillations

A dynamic variational multiscale method on unstructured meshes for stationary transport problems

Influence of Swirl Flow Pattern in Single Tube Burner on Turbulent Flame Blow-Off Limit

Contact Info

Product

Resources

About