Modeling Vortex Generators in a Navier-Stokes Code

Dudek, Julianne C.

doi:10.2514/1.j050683

Cited by 43 publications

(17 citation statements)

References 13 publications

(26 reference statements)

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“…The source term modeling is known as the BAY model in Wind-US. 8 The BAY model has been applied for vane-type vortex generators within subsonic and supersonic flows. 8 The BAY model does not account for the viscous forces on the vanes, and so, the losses in total pressure due to the vanes are not modeled.…”

Section: B Source Term Vortex Generator Modelmentioning

confidence: 99%

“…8 The BAY model has been applied for vane-type vortex generators within subsonic and supersonic flows. 8 The BAY model does not account for the viscous forces on the vanes, and so, the losses in total pressure due to the vanes are not modeled. The inputs to the BAY model include the grid range that would contain the vane, the angle-of-incidence of the vane, and the planform area of the vane.…”

Section: B Source Term Vortex Generator Modelmentioning

confidence: 99%

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Vortex Generators in a Streamline-Traced, External-Compression Supersonic Inlet

Baydar

Lu²,

Slater

et al. 2017

55th AIAA Aerospace Sciences Meeting

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Vortex generators within a streamline-traced, external-compression supersonic inlet for Mach 1.66 were investigated to determine their ability to increase total pressure recovery and reduce total pressure distortion. The vortex generators studied were rectangular vanes arranged in counter-rotating and co-rotating arrays. The vane geometric factors of interest included height, length, spacing, angle-of-incidence, and positions upstream and downstream of the inlet terminal shock. The flow through the inlet was simulated numerically through the solution of the steady-state, Reynolds-averaged Navier-Stokes equations on multi-block, structured grids using the Wind-US flow solver. The vanes were simulated using a vortex generator model. The inlet performance was characterized by the inlet total pressure recovery and the radial and circumferential total pressure distortion indices at the engine face. Design of experiments and statistical analysis methods were applied to quantify the effect of the geometric factors of the vanes and search for optimal vane arrays. Co-rotating vane arrays with negative angles-of-incidence positioned on the supersonic diffuser were effective in sweeping low-momentum flow from the top toward the sides of the subsonic diffuser. This distributed the low-momentum flow more evenly about the circumference of the subsonic diffuser and reduced distortion. Co-rotating vane arrays with negative angles-of-incidence or counter-rotating vane arrays positioned downstream of the terminal shock were effective in mixing higher-momentum flow with lower-momentum flow to increase recovery and decrease distortion. A strategy of combining a co-rotating vane array on the supersonic diffuser with a counter-rotating vane array on the subsonic diffuser was effective in increasing recovery and reducing distortion.

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Section: B Source Term Vortex Generator Modelmentioning

confidence: 99%

Section: B Source Term Vortex Generator Modelmentioning

confidence: 99%

Vortex Generators in a Streamline-Traced, External-Compression Supersonic Inlet

Baydar

Lu²,

Slater

et al. 2017

55th AIAA Aerospace Sciences Meeting

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“…20,21 The model mimics the effect of VGs on the flow by approximately enforcing flow tangency in a group of cells in the vicinity of the VG location. This is achieved using local source terms in the momentum equation of the form…”

Section: The Bay and Jbay Modelsmentioning

confidence: 99%

Effectiveness of Side Force Models for Flow Simulations Downstream of Vortex Generators

et al. 2017

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Vortex generators (VGs) are a widely used means of flow control, and predictions of their influence are vital for efficient designs. However, accurate CFD simulations of their effect on the flow field by means of a body fitted mesh are computationally expensive. Therefore the BAY and jBAY models, which represent the effect of VGs on the flow using source terms in the momentum equations, are popular in industry. In this contribution we examine the ability of the BAY and jBAY model to provide accurate flow field results by looking at boundary layer properties close behind VGs. The results are compared with both body fitted mesh and other source term model RANS simulations of 3D incompressible flows, over flat plate and airfoil geometries. We show the influence of mesh resolution and domain of application on the accuracy of the models and investigate the influence of the source term on the generated flow field. Our results demonstrate the grid dependence of the models and indicate the presence of model errors. Furthermore we find that the total applied force has a larger influence on both the intensity and shape of the created vortex than the distribution of the source term over the cells.

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“…A few approaches to the design of such a body force are available in the literature (see, e.g., [18][19][20][21][22][23]). In this study, we use a simple approach that is based on the direct numerical simulation study of Liu et al [23] and was shown to be robust and quite accurate within SARC SRANS computations in [24].…”

Section: Representation Of Vortex Generators By a Body Forcementioning

confidence: 99%

Evaluation of Vortex Generators for Separation Control in a Transcritical Cylinder Flow

et al. 2015

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A numerical study is presented, aimed at evaluating the capability of vortex generators to produce a significant delay of separation and drag reduction in flows past smooth bluff bodies in the transcritical flow regime, with turbulent boundary layers ahead of separation. A fairly large series of steady Reynolds-averaged Navier-Stokes computations is carried out of the incompressible flow past a circular cylinder, with a simple and generic geometry, with and without vortex generators. Their effect is emulated with a body force, applied in a refined-grid region, instead of gridding the actual geometry. The flow is treated as steady, for reasons that are discussed. The parametric study includes 10 different vortex generator designs, as well as varying positions, spacings, and heights. Drag reductions of up to 60% are obtained, including those with sub-boundary-layer designs, with a height equal to half the boundary-layer thickness. Design recommendations are given, with the tolerance to vortex shedding and other variations in the flow conditions taken into account. Nomenclature= components of body-force-emulating vortex generators in local coordinate system g 0x , g 0 y , g 0 z = functions controlling spatial variation of body-force components h = height of vortex generator k = turbulent kinetic energy L z = distance between vortex generators in array U, V, W = velocity components in global coordinate system fx; y; zg u, v, w = velocity components in local coordinate system fx 0 ; y 0 ; z 0 g α = polar angle of a point on cylinder surface (zero at forward stagnation point) β = angle of attack Γ = circulation Δ = half-width of vortex generator ν = molecular viscosity ν t = eddy viscosity τ xy = shear stress ω = specific dissipation rate of turbulent kinetic energy Subscripts w = parameters on cylinder wall 0 = parameters at vortex generator location ∞ = freestream parameters

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Modeling Vortex Generators in a Navier-Stokes Code

Cited by 43 publications

References 13 publications

Vortex Generators in a Streamline-Traced, External-Compression Supersonic Inlet

Vortex Generators in a Streamline-Traced, External-Compression Supersonic Inlet

Effectiveness of Side Force Models for Flow Simulations Downstream of Vortex Generators

Evaluation of Vortex Generators for Separation Control in a Transcritical Cylinder Flow

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