Reduction of Aft Fuselage Drag on the C-130 Using Microvanes

Smith, Brian R.; Yagle, Patrick J.; Hooker, John R.

doi:10.2514/6.2013-105

Cited by 19 publications

(7 citation statements)

References 4 publications

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“…Wortman (1999) also tested different vortex generator geometries on scale models of Boeing 747 and Lockheed C5 afterbodies reporting drag reductions of 3 and 6%, respectively. Lockheed Martin carried out a combined CFD and flight test program to investigate the effect of microvanes on the afterbody drag on a C-130 (Smith et al 2013). The microvanes tested consisted of a snug-free design to avoid interference with airdropping missions.…”

Section: List Of Symbols a Mmentioning

confidence: 99%

Afterbody vortices of axisymmetric cylinders with a slanted base

et al. 2017

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Section: List Of Symbols a Mmentioning

confidence: 99%

Afterbody vortices of axisymmetric cylinders with a slanted base

et al. 2017

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“…Both the Falcon flow solver and the k-kl turbulence model have been validated extensively for external and internal flows over a range of Mach numbers. Falcon has been used extensively to simulate complex flows for the F-35 19 and C-130, 20 generating good agreement with wind tunnel data.…”

Section: Flow Solver Descriptionmentioning

confidence: 98%

Modification of the k-kl Two Equation Turbulence Model for Improved Jet Flow Predictions (Invited)

Smith

2015

22nd AIAA Computational Fluid Dynamics Conference

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Reynolds averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) methods are relied on for design and analysis of both conventional and STOVL tactical military aircraft. Application of one and two transport equation turbulence models is the standard approach used to account for the effects of turbulence. While the commonly used turbulence models predict flows in wall boundary layers and wakes with reasonable accuracy, they typically do not predict jet flows well. As a result, predictions of jet effects and jet environments as part of vehicle computations are inaccurate when these models are used. In this work, modifications that improve jet flow predictions for the k-kl two transport equation turbulence model are presented. The improved model gives accurate predictions of wall turbulent boundary layers and 2-D shear layers consistent with the baseline k-kl model. Results for the modified model are presented for a series of subsonic, near sonic and hot axisymmetric jet flows. While the baseline k-kl model gives results that are comparable in accuracy to other commonly used turbulence models, the modified model gives much more accurate results for all of the jet flows considered while maintaining accuracy for a wall turbulent boundary layer.

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“…More recent studies into the efficacy of different designs of passive vortex generators have shown promising drag reduction results. [6][7][8] In these solutions, the passing of air over arrays of small strakes generates additional vortices that may interact with the afterbody vortices. However, in some instances, these passive flow control designs can create operational difficulties during airdrop missions and the loading/unloading of cargo.…”

Section: Introductionmentioning

confidence: 98%

“…However, in some instances, these passive flow control designs can create operational difficulties during airdrop missions and the loading/unloading of cargo. 8 A gap in the existing research has been identified within the application of blowing techniques to the afterbody vortex problem. Previous research has shown that there is potential for rapid diffusion of wing tip vortices in the near-wake by means of ingestion of jet turbulence from continuous jets.…”

Section: Introductionmentioning

confidence: 98%

Control of Afterbody Vortices by Blowing

Jackson

Wang

Gursul

2015

45th AIAA Fluid Dynamics Conference

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An experimental study has been performed to examine the effect of blowing via a pair of jets from the upswept face of a slanted base cylinder, upon the development of the afterbody vortex flow field. Jet vortices initially interact with the shear layer separated from the upswept section. The nature of the early interactions between the jet and shear layer is highly dependent upon the blowing direction. For most blowing configurations tested, the shear layer becomes wrapped around the jet vortex. The most significant evidence of modification of the afterbody vortex pair was found when initiating a jet vortex further outboard and closer to the shear layer. The jet/vortex interactions initially cause the afterbody vortices to form further outboard, at a greater distance from the surface, and with a smaller vortex core. There is a reduction in the circulation over the first half of the afterbody length, before it recovers to baseline levels at the trailing edge. The vortex pair appears more diffuse near the trailing edge, but this is a result of increased meandering. Nomenclature am = meandering amplitude xj = streamwise jet location Aj = cross-sectional area of jet y = normal distance c = chord length of upswept face z = spanwise distance Cµ = jet momentum coefficient, ρAjUj 2 /0.5ρU∞ 2 S zj = spanwise jet location D = diameter of fuselage α = fuselage incidence angle L = length of afterbody αj = jet incidence angle r = distance from vortex center β = fuselage yaw angle Re = Reynolds number, ρU∞D/µ βj = jet yaw angle S = cross-sectional area of fuselage Γ = circulation Uj = jet velocity µ = viscosity U∞ = freestream velocity ρ = density V = crossflow velocity ω = vorticity x = streamwise distance

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Reduction of Aft Fuselage Drag on the C-130 Using Microvanes

Cited by 19 publications

References 4 publications

Afterbody vortices of axisymmetric cylinders with a slanted base

Afterbody vortices of axisymmetric cylinders with a slanted base

Modification of the k-kl Two Equation Turbulence Model for Improved Jet Flow Predictions (Invited)

Control of Afterbody Vortices by Blowing

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