9-Apr-2008 WALLTURB meeting at ONERA Toulouse WALLTURB: CFD results on Surrey Bump WALLTURB Presented by Jerry Benton.

9-Apr-2008 WALLTURB meeting at ONERA Toulouse WALLTURB: CFD results on Surrey Bump WALLTURB Presented by Jerry Benton

© AIRBUS UK LTD. All rights reserved. Confidential and proprietary document. 9-Apr-2008WALLTURB meeting at ONERA ToulousePage 2 Surrey bump. Medium mesh Medium: X=-7.76m Fine: X=-8.129m Length of plate adjusted to match measured momentum thickness at x=-1.534m. Transition fixed at 0.1m from plate leading edge. Fine mesh has approx double the number of points in bl normal to wall compared to medium mesh, same spacing in viscous sublayer, same streamwise spacing. 3m Inflow region Plate Top wall Colours indicate mesh blocks Viscous sublayer: mesh adjusted so 1 st cell y+ is in range 0.8 to 1 everywhere (though this cannot be maintained through separation region). Then 2 nd and 3 rd cells have same height as 1 st. Viscous walls Inviscid walls Y=0.5m Y=0.0m X=0 X=+1.456m Bump X=+0.77m X=-1.534mX=0

© AIRBUS UK LTD. All rights reserved. Confidential and proprietary document. 9-Apr-2008WALLTURB meeting at ONERA ToulousePage 3 Flow details 2D only - no sidewall boundary layer Upstream plate length adjusted (for each mesh) so momentum thickness matches experiment at upstream reference point x=-1.534m Re(  ) matches experiment at x=-1.534m Same inflow “leading edge” top and bottom, and same position, despite different geometry and bl suction in experiment U velocity is always x-direction, not tangential 2 turbulence models used: kw Menter baseline (BSL) kw Menter SST All CFD plots show 3 results (except 1 slide on flat plate zpg): Blue:medium meshkw BSL Black:fine mesh,kw BSL Red:fine mesh,kw SST Solver: structured multiblock, compressible, run at inflow M ~ 0.18 Spatial discretisation is 2nd order. Scalar dissipation, set at relatively low level, purely 3rd order in absence of shocks, inversely scaled with local viscosity, no preconditioning

© AIRBUS UK LTD. All rights reserved. Confidential and proprietary document. 9-Apr-2008WALLTURB meeting at ONERA ToulousePage 5 Cp in bump region Compressibility effects? Kw SST tends to overpredict separation Kw BSL tends to underpredict separation

© AIRBUS UK LTD. All rights reserved. Confidential and proprietary document. 9-Apr-2008WALLTURB meeting at ONERA ToulousePage 11 Flat plate zpg validation for Re(L)=1,10,100mil Influence of turbulence model

© AIRBUS UK LTD. All rights reserved. Confidential and proprietary document. 9-Apr-2008WALLTURB meeting at ONERA ToulousePage 12 U profiles at x=-1.534 and x=-.336 Question re overprediction of mean velocity cf measurements at x=-1.534m and x=-.336m in the range y=.01 to.04m Could this be due to 3D effects, specifically that the core flow acceleration due to the sidewall boundary layer is not maintained into the lower part of the bottom plate and top wall bl? A physical argument could be that the full displacement effect of the sidewall bl, as felt by the core flow, is not fully maintained in the tunnel corner regions, the total displacement effect here being shared between plate and sidewall bl, and not equal to the sum of the displacement thicknesses at the centreline of each bl. The idea is that this shortfall in displacement is then propagated across the plate and top wall bl. A 3D CFD study would be useful to investigate this.

© AIRBUS UK LTD. All rights reserved. Confidential and proprietary document. 9-Apr-2008WALLTURB meeting at ONERA ToulousePage 39 Future work Surrey experiment: further checks/refinement of numerical issues Alternative turbulence models Transonic wing-body (HiReTT) Lille and Czestochowa experiments

© AIRBUS UK LTD. All rights reserved. Confidential and proprietary document. 9-Apr-2008WALLTURB meeting at ONERA ToulousePage 40 © AIRBUS UK LTD. All rights reserved. Confidential and proprietary document. This document and all information contained herein is the sole property of AIRBUS UK LTD. No intellectual property rights are granted by the delivery of this document or the disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of AIRBUS UK LTD. This document and its content shall not be used for any purpose other than that for which it is supplied. The statements made herein do not constitute an offer. They are based on the mentioned assumptions and are expressed in good faith. Where the supporting grounds for these statements are not shown, AIRBUS UK LTD will be pleased to explain the basis thereof. AIRBUS, its logo, A300, A310, A318, A319, A320, A321, A330, A340, A350, A380, A400M are registered trademarks.

9-Apr-2008 WALLTURB meeting at ONERA Toulouse WALLTURB: CFD results on Surrey Bump WALLTURB Presented by Jerry Benton.

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9-Apr-2008 WALLTURB meeting at ONERA Toulouse WALLTURB: CFD results on Surrey Bump WALLTURB Presented by Jerry Benton.

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Presentation on theme: "9-Apr-2008 WALLTURB meeting at ONERA Toulouse WALLTURB: CFD results on Surrey Bump WALLTURB Presented by Jerry Benton."— Presentation transcript:

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