Reynolds-Averaged Navier-Stokes Analysis of Zero Efflux Flow Control over a Hump Model

Rumsey, Christopher L.

doi:10.2514/6.2006-1114

Cited by 11 publications

(7 citation statements)

References 17 publications

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“…(14)(15)(16)(17) to determine the new inflow profile (taking p p 1 across the boundary layer): The first RR improvement we consider for comparison is the improvement suggested by Spalart et al [15]. With this improvement, before the rescaled profile is reintroduced as the updated inflow boundary condition, it is first translated a distance of L z =2 (taking advantage of the periodic boundary conditions in the spanwise direction).…”

Section: Iib Recycling/rescaling Turbulence Inflow Methodsmentioning

confidence: 99%

“…While a full description of the found in [3], Table 4 summarizes the key uired that the desired streamwise integral ed as well as the two-dimensional filter ize determines the imposed length scales, e used for each velocity component: one gion and one outside. These values were es used in [3], scaled to the present grid resent work, no density or temperature although, this could be done by invoking gy: dures have been proposed [12][13][14]31], we in and Knight [13]. Figure 1 illustrates the le is captured some distance downstream scaled appropriately, and reintroduced as n. is first decomposed into a mean and nd the mean components are scaled to y effects according to Eqs.…”

Section: Iib Recycling/rescaling Turbulence Inflow Methodsmentioning

confidence: 99%

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Implicit LES of turbulent, separated flow: wall-mounted hump configuration

Sekhar

Mansour

Caubilla

2015

53rd AIAA Aerospace Sciences Meeting

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Direct simulations (ILES) of turbulent, separated flow over the wall-mounted hump configuration is conducted to investigate the physics of separated flows. A chord-based Reynolds number of Rec = 47,500 is set up, with a turbulent inflow of Re θ = 1,400 (θ/c = 3%). FDL3DI, a code that solves the compressible Navier-Stokes equations using highorder compact-difference scheme and filter, with the standard recycling/rescaling method of turbulence generation, is used. Two different configurations of the upper-wall are analyzed, and results are compared with both a higher Rec (= 936,000, Re θ = 7,200, θ/c = 0.77%) experiment for major flow features, and RANS (k-ω SST) results. A lower Rec allows for DNS-like mesh resolution, and an adequately wide span. Both ILES and RANS show earlier separation and delayed reattachment compared to experiment, and significantly higher skin friction in the forebody of the hump, as expected. The upper-wall shape only influences the pressure distribution over the hump. Results from this study are being used to setup higher Rec (lower θ/c) ILES.

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Section: Iib Recycling/rescaling Turbulence Inflow Methodsmentioning

confidence: 99%

Section: Iib Recycling/rescaling Turbulence Inflow Methodsmentioning

confidence: 99%

Implicit LES of turbulent, separated flow: wall-mounted hump configuration

Sekhar

Mansour

Caubilla

2015

53rd AIAA Aerospace Sciences Meeting

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“…CFL3D is globally second order spatially accurate, and can be used to solve time accurate problems with moving bodies and with flow control applied at walls. 65 For time accurate problems, CFL3D utilizes pseudo time stepping and achieves second order temporal accuracy. With pseudo time stepping, sub-iterations are used to reduce the linearization and factorization errors, and advance the solution in pseudo time to the next physical time.…”

Section: Description Of Cfd Code Used For Unsteady Flow Predictionsmentioning

confidence: 99%

Unsteady Thick Airfoil Aerodynamics: Experiments, Computation, and Theory

Stangfeld

Rumsey

Mueller-Vahl

et al. 2015

45th AIAA Fluid Dynamics Conference

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An experimental, computational and theoretical investigation was carried out to study the aerodynamic loads acting on a relatively thick NACA 0018 airfoil when subjected to pitching and surging, individually and synchronously. Both pre-stall and post-stall angles of attack were considered. Experiments were carried out in a dedicated unsteady wind tunnel, with large surge amplitudes, and airfoil loads were estimated by means of unsteady surface mounted pressure measurements. Theoretical predictions were based on Theodorsen's and Isaacs' results as well as on the relatively recent generalizations of van der Wall. Both two-and three-dimensional computations were performed on structured grids employing unsteady Reynolds-averaged Navier-Stokes (URANS). For pure surging at pre-stall angles of attack, the correspondence between experiments and theory was satisfactory; this served as a validation of Isaacs theory. Discrepancies were traced to dynamic trailing-edge separation, even at low angles of attack. Excellent correspondence was found between experiments and theory for airfoil pitching as well as combined pitching and surging; the latter appears to be the first clear validation of van der Wall's theoretical results. Although qualitatively similar to experiment at low angles of attack, two-dimensional URANS computations yielded notable errors in the unsteady load effects of pitching, surging and their synchronous combination. The main reason is believed to be that the URANS equations do not resolve wake vorticity (explicitly modeled in the theory) or the resulting rolled-up unsteady flow structures because high values of eddy viscosity tend to "smear" the wake. At post-stall angles, three-dimensional computations illustrated the importance of modeling the tunnel side walls.

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“…The LES simulations of You, Wang & Moin 5 yielded good predictions of the reattachment location and Reynolds stresses. Some of the computational studies for this configuration were performed by Saric et al, 6 Morgan et al, 7 Rumsey, 8 Balakumar 9 and Krishnan et al 10 More recent computations include those by Avdis et al, 11 Franck & Colonius, 12 Yeh et al, 13 Sekhar et al, 14 Woodruff, 15 Duda & Fares 16 and Kalsi & Tucker. 17 Park 18 performed WMLES using an equilibrium and non-equilibrium wall model for the same NASA hump configuration and obtained reasonable agreement with experiment.…”

Section: Introductionmentioning

confidence: 96%

Wall--modeled Large Eddy Simulation of Flow Over a Wall--mounted Hump

Iyer

Malik

2016

46th AIAA Fluid Dynamics Conference

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Large eddy simulation (LES) with an equilibrium wall model is used to study the flow past a wall-mounted hump at conditions matching the experiments of Greenblatt et al. based on the hump chord (Rec = u∞c/ν∞) is 936,000 and the freestream Mach number (M∞) is 0.1. The Reynolds number of the flow approaching the hump is about 7,000 based on the momentum thickness. This configuration has proved to be a challenging test case with most Reynolds-Averaged Navier-Stokes (RANS) models overpredicting the separation bubble length. While the present wall-modeled LES simulations capture the bubble length within 3.4% of the experiment and mean statistics in the separation bubble reasonably well, they do not accurately predict the skin friction distribution in the separated region. The effect of grid resolution and exchange location for information from LES to the wall model is studied by qualitative and quantitative comparisons to experiment. The fine grid simulation with the exchange location placed away from the wall gives the best agreement overall with experiment.

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Reynolds-Averaged Navier-Stokes Analysis of Zero Efflux Flow Control over a Hump Model

Cited by 11 publications

References 17 publications

Implicit LES of turbulent, separated flow: wall-mounted hump configuration

Implicit LES of turbulent, separated flow: wall-mounted hump configuration

Unsteady Thick Airfoil Aerodynamics: Experiments, Computation, and Theory

Wall--modeled Large Eddy Simulation of Flow Over a Wall--mounted Hump

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