RANS Technology for Transonic Drag Prediction; A Boeing Perspective of the 4th Drag Prediction Workshop

Mani, Mori; Rider, Ben; Sclafani, Anthony; Winkler, Chad; Vassberg, John C.; Dorgan, Andrew J.; Cary, Andrew W.; Tinoco, Edward N.

doi:10.2514/6.2010-4221

Cited by 21 publications

(10 citation statements)

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“…Details of these tests and a description of the corrections applied to the experimental data can be found in Ref. 47. "Pseudo" drag is not shown in that the twist corrections are of the same order as the spread between repeat runs and would add nothing to the comparison.…”

Section: Case 2: Crm Buffet Studymentioning

confidence: 99%

“…While this improvement is quite significant, the confidence level is not down to a low enough level to compete with experimental methods. Documentation for these results can be found in summary papers [43][44] and in individual contributing papers [45][46][47][48][49][50][51][52][53][54][55][56][57][58] from two special sessions held at the 28 th Applied Aerodynamics Conference in June 2010.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

Self Cite

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: Case 2: Crm Buffet Studymentioning

confidence: 99%

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

Self Cite

104

View full text Add to dashboard Cite

show abstract

“…However, the details of these grids are not included herein. For more information regarding these grids, please refer to the companion papers [54][55][56][57][58][59][60][61][62][63][64][65][66][67] associated with this summary document. Because of the variation of grid types needed, a set of gridding guidelines, listed below, is established to help facilitate the creation of these grids.…”

Section: Baseline Gridsmentioning

confidence: 99%

Summary of the Fourth AIAA CFD Drag Prediction Workshop

Vassberg

Tinoco

Mani

et al. 2010

28th AIAA Applied Aerodynamics Conference

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184

111

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Results from the Fourth AIAA Drag Prediction Workshop (DPW-IV) are summarized. The workshop focused on the prediction of both absolute and differential drag levels for wing-body and wing-body-horizontal-tail configurations that are representative of transonic transport aircraft. Numerical calculations are performed using industry-relevant test cases that include liftspecific flight conditions, trimmed drag polars, downwash variations, dragrises and Reynoldsnumber effects. Drag, lift and pitching moment predictions from numerous Reynolds-Averaged Navier-Stokes computational fluid dynamics methods are presented. Solutions are performed on structured, unstructured and hybrid grid systems. The structured-grid sets include pointmatched multi-block meshes and over-set grid systems. The unstructured and hybrid grid sets are comprised of tetrahedral, pyramid, prismatic, and hexahedral elements. Effort is made to provide a high-quality and parametrically consistent family of grids for each grid type about each configuration under study. The wing-body-horizontal families are comprised of a coarse, medium and fine grid; an optional extra-fine grid augments several of the grid families. These mesh sequences are utilized to determine asymptotic grid-convergence characteristics of the solution sets, and to estimate grid-converged absolute drag levels of the wing-body-horizontal configuration using Richardson extrapolation.

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“…Increasing the wing root juncture grid resolution with a finer orthogonal grid increased the extent of separation. Mani et al 20 used OVERFLOW to show a small bubble at the CRM design condition that shrunk with grid refinement. The bubble was larger with FNS than the TLNS approximation.…”

Section: Dpw-ivmentioning

confidence: 99%

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

Park

Laflin²,

Chaffin³

et al. 2014

Journal of Aircraft

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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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RANS Technology for Transonic Drag Prediction; A Boeing Perspective of the 4th Drag Prediction Workshop

Cited by 21 publications

References 1 publication

Summary of Data from the Fifth AIAA CFD Drag Prediction Workshop

Summary of Data from the Fifth AIAA CFD Drag Prediction Workshop

Summary of the Fourth AIAA CFD Drag Prediction Workshop

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

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