Experimental Investigations of the NASA Common Research Model in the NASA Langley National Transonic Facility and NASA Ames 11-Ft Transonic Wind Tunnel (Invited)

Rivers, Melissa B.; Dittberner, Ashley; Sverdrup, Jacobs

doi:10.2514/6.2011-1126

Cited by 117 publications

(83 citation statements)

References 27 publications

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“…The National Transonic Facility (NTF) at NASA Langley tested the CRM during Jan-Feb 2010, and then it was evaluated at the Ames 11-ft wind-tunnel during Mar-Apr 2010. Data from the NTF and Ames tests have been released to the public domain by Rivers and Dittberner [40][41][42] . Due to past observations of grid dependence on the solutions, a greater emphasis was placed on establishing meshing guidelines for the generation of baseline grid families.…”

Section: Introductionmentioning

confidence: 99%

Summary of Data from the Fifth AIAA CFD Drag Prediction Workshop

Levy¹,

Laflin²,

Tinoco

et al. 2013

51st AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

104

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Results from the Fifth AIAA CFD Drag Prediction Workshop (DPW-V) are presented. As with past workshops, numerical calculations are performed using industry-relevant geometry, methodology, and test cases. This workshop focused on force/moment predictions for the NASA Common Research Model wing-body configuration, including a grid refinement study and an optional buffet study. The grid refinement study used a common grid sequence derived from a multiblock topology structured grid. Six levels of refinement were created resulting in grids ranging from 0.64x10 6 to 138x10 6 hexahedra -a much larger range than is typically seen. The grids were then transformed into structured overset and hexahedral, prismatic, tetrahedral, and hybrid unstructured formats all using the same basic cloud of points. This unique collection of grids was designed to isolate the effects of grid type and solution algorithm by using identical point distributions. This study showed reduced scatter and standard deviation from previous workshops. The second test case studied buffet onset at M=0.85 using the Medium grid (5.1x10 6 nodes) from the above described sequence. The prescribed alpha sweep used finely spaced intervals through the zone where wing separation was expected to begin. Some solutions exhibited a large side of body separation bubble that was not observed in the wind tunnel results. An optional third case used three sets of geometry, grids, and conditions from the Turbulence Model Resource website prepared by the Turbulence Model Benchmarking Working Group. These simple cases were intended to help identify potential differences in turbulence model implementation. Although a few outliers and issues affecting consistency were identified, the majority of participants produced consistent results.

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Section: Introductionmentioning

confidence: 99%

Summary of Data from the Fifth AIAA CFD Drag Prediction Workshop

Levy¹,

Laflin²,

Tinoco

et al. 2013

51st AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

104

View full text Add to dashboard Cite

show abstract

“…At DPW-IV, the participants were unsure of the validity of this side-of-body separation because the configuration was not wind tunnel tested before DPW-IV. The wind tunnel tests 13,14 after DPW-IV did not indicate the abrupt drop in lift associated with the side-of-body separation predicted by some of the DPW-IV participants. Neither measured skin friction or oil flow visualizations 16 indicated a large wing root separation bubble at 4 degrees angle of attack.…”

Section: Dpw-ivmentioning

confidence: 99%

CFL3D, FUN3D, and NSU3D Contributions to the Fifth Drag Prediction Workshop

Park

Laflin²,

Chaffin³

et al. 2013

51st AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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Results presented at the Fifth Drag Prediction Workshop using CFL3D, FUN3D, and NSU3D are described. These are calculations on the workshop provided grids and drag adapted grids. The NSU3D results have been updated to reflect an improvement to skin friction calculation on skewed grids. FUN3D results generated after the workshop are included for custom participant generated grids and a grid from a previous workshop. Uniform grid refinement at the design condition shows a tight grouping in calculated drag, where the variation in the pressure component of drag is larger than the skin friction component. At this design condition, A fine-grid drag value was predicted with a smaller drag adjoint adapted grid via tetrahedral adaption to a metric and mixed-element subdivision. The buffet study produced larger variation than the design case, which is attributed to large differences in the predicted side-of-body separation extent. Various modeling and discretization approaches had a strong impact on predicted side-of-body separation. This large wing root separation bubble was not observed in wind tunnel tests indicating that more work is necessary in modeling wing root juncture flows to predict experiments.

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“…The transport aircraft model may encounter large sting vibration when the attack angle approaches the second pitching moment break, which can sometimes become divergent. An active damping system has been developed in the National Transonic Facility [13,14] and European Transonic Wind Tunnel [15] and apparent effects were achieved. However, there are only few works on an optimal sting design which can reduce interference based on the CFD.…”

Section: Introductionmentioning

confidence: 99%

The Optimal Design of a Wind Tunnel Model Sting System Based on the CFD Method

Li¹,

Liu²,

Li³

2015

IJHT

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This paper aims to design a sting support system for a transonic wind tunnel test for a commercial wide-bodied aircraft, which includes a single sting and a blade support. Parameters of the sting support system have been analyzed and three key parameters are selected for optimization. A RANS solver has been developed to investigate the effects of key parameters on the sting support interference. Influences of four incidence angles and five locations of an expanding point on the single sting interference are studied, and also the effects of six vane leading edge sweep angles on the blade support interference are investigated. The optimal key parameters are determined, based on numerical results and structural rigidity. Structural intensity verification of the optimized support system has been performed under the estimated aerodynamic loading by commercial software. Results indicate that a 6° incidence angle and 03 expanding point are the optimal parameters for a single sting and a 50° leading edge sweep angle of the vane is optimal for blade support. The optimized sting system with sufficient safety factors is suitable for commercial wide-bodied aircraft wind tunnel tests, which implies the method in this paper can be used to optimize the sting support system of other vehicles.

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Experimental Investigations of the NASA Common Research Model in the NASA Langley National Transonic Facility and NASA Ames 11-Ft Transonic Wind Tunnel (Invited)

Cited by 117 publications

References 27 publications

Summary of Data from the Fifth AIAA CFD Drag Prediction Workshop

Summary of Data from the Fifth AIAA CFD Drag Prediction Workshop

CFL3D, FUN3D, and NSU3D Contributions to the Fifth Drag Prediction Workshop

The Optimal Design of a Wind Tunnel Model Sting System Based on the CFD Method

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