Reynolds number influence on delta wing vortex · PDF fileTechnische Universität München 1 PD Dr.-Ing. C. Breitsamter, Dipl.-Ing. J.-U. Klar Reynolds number influence on delta wing

Technische Universität München

1PD Dr.-Ing. C. Breitsamter, Dipl.-Ing. J.-U. Klar

Reynolds number influence on Reynolds number influence on delta wing vortex flowsdelta wing vortex flows

TUMTUM--AER projectAER project

Outline

Background and expertise

Objectives and exploitation

ETW experiments – model & instrumentation

Partners – consortium







Outline



Flow physics Flow physics –– basicsbasics

Angle of attack α

Boundary layer(laminar / turbulent)

Wing sweep φ(planform)

Leading-edge radius rN(airfoil)

Main parameters

Incident and surface flow

Geometry

rN

φ

U∞w

α

Evolution of large scale vortices … determine lift characteristics, maneuver capabilities and stability

Background



Flow physics Flow physics –– basicsbasics

Vortex development depend on leading-edge sweep φ and angle of attack α40

2: Fully developedvortex, moving inboard

3: Span–wisefixed vortex

0

5

10

35

30

25

20

15

50 8555 60 65 70 75 80

α [°]

φ [°]

∆α

2 α

4 α

αmax

αBursting(trailing–edge)

Thin, planar wings;sharp leading–edgeThin, planar wings;sharp leading–edge

1: Vortex formation

4: Vortex bursting over the wing

1 α

3φW

laminar

turbulent

laminarturbulent

Background



Flow physics Flow physics –– Re influence Re influence (secondary separation)

Separation line of secondary vortex

Laminarregion

Turbulentregion

Transition

xy

νxU

x∞=Re

y

–CP

y

–CP

uppercrit ,ReRe >Upper- / lower side:

Laminar / laminar : Rex < 0.9 x 106 = Recrit,upper

y

–CP

lowercrit ,ReRe >

Turbulent / laminar : 0.9 x 106 < Rex < 1.9 x 106

Turbulent / turbulent : Rex > 1.9 x 106 = Recrit,lower

Background



VFEVFE--2 2 (RTO(RTO--AVTAVT--113, RTO113, RTO--AVTAVT--183)183)

Expertise



VFEVFE--2 configuration 2 configuration –– Geometry Geometry

crb

= 0.

933

c rφ = 65°

Sharp LERounded LE

0.15 cr 0.10 cr

t = 0.034 cr

r/lµ = 0.15 %

Expertise



VFEVFE--2 2 configconfig. . –– TUMTUM––AERAER wind tunnel model wind tunnel model

Sharp leading-edgeRounded leading-edger/lµ = 0.0015

Expertise



VFEVFE--2 2 configconfig. . –– TUMTUM––AERAER wind tunnel model wind tunnel model

2/3 crlµmean aerodynamic chord

0.914 mb = 2swing span

65°φleading edge sweep1.865Λaspect ratio

0.448 m2Fwing area

0.980 mcrroot chord

Expertise



VFEVFE--2 2 configconfig. . –– TUMTUM––AERAER model instrumentation model instrumentation

crb

= 0.

933

c rφ = 65°

0.2 0.4 0.6 0.8 0.95

177 pressure pos.:diam. 0.3 mm

5 chord stations

0.15 cr 0.10 cr

t = 0.034 cr 133 steady sensors (PSI)

44 unsteady sensors (Kulites)



Laser light sheet Laser light sheet flow visualizationflow visualizationBurst leading–edge vortex; α = 30°:

x/cr = 0.20x/cr = 0.40x/cr = 0.60x/cr = 0.80x/cr = 0.95x/cr = 1.10

Expertise



Laser light sheet Laser light sheet flow visualizationflow visualizationFully developed leading–edge vortex; α = 18°:

Sharp leading edge Rounded leading edge

Expertise



Flow field Flow field –– mean velocitymean velocityPartly developed leading–edge vortex; α = 13°:

x/cr = 0.2, 0.4, 0.6, 0.8, and 0.95:

Expertise



Flow field Flow field –– turbulence intensityturbulence intensityPartly developed leading–edge vortex; α = 13°:

x/cr = 0.4x/cr = 0.4 x/cr = 0.6x/cr = 0.6 x/cr = 0.8x/cr = 0.8

urms/U∞urms/U∞

Expertise



Flow field Flow field –– turbulence intensityturbulence intensityBurst leading–edge vortex; α = 23°:

x/cr = 0.4x/cr = 0.4 x/cr = 0.6x/cr = 0.6 x/cr = 0.8x/cr = 0.8

urms/U∞urms/U∞

Expertise



Re = 2.0 x 106

α = 23°Re = 2.0 x 106

α = 23°

Surface pressure Surface pressure –– turbulence intensityturbulence intensity



Complex flow topology Complex flow topology –– Re influence / multiple vorticesRe influence / multiple vortices

Ma = 0.4 (const.)

Re = 1 x 106 Re = 2 x 106 Re = 3 x 106

URANS simulations

(Courtesy W. Fritz, AIAA Paper 2008-393)

Expertise



Flow physics Flow physics –– Re influence Re influence

U∞

Laminarseparation

Turbulentseparation

Secondary vortex

Primary vortex

Inboard vortex

AttachmentSeparation



Topology ofvortex system

M = 0.14 Re = 2.0 x 106

α = 13°

Oil flow

Expertise



Flow physics Flow physics –– Re influence Re influence

TUM – Oil flow

M = 0.14 Re = 2.0 x 106

α = 13°

DLR – TSP

VFE-2delta wing

KKK tests (T: 240 K – 150 K)(Courtesy R. Konrath)

Ma = 0.05 – 0.16

Re = 1 x 106 – 6 x 106

α = 5° – 28°

Expertise







Outline



Flow physics Flow physics –– Re influenceRe influence

Separating shear layer

Vortex core (fully developed / bursting)

Boundary layer – secondary separation

φ

α = 30.0°

α = 25.0°

U∞

φ = 76°

0.02

0.28

0.20

0.10

∞′ Uu 2

Associated characteristic instabilities





Re = 2.0 x 106

α = 18°Multiple vortex system Re = const.

α

Laminarseparation

Turbulentseparation





α = 18°Re = 1·106

Rounded leading edge




Objectives Objectives

Analysis of aerodynamic characteristics and corresponding flow topologies – selected test cases

Improving flow physics knowledge and modeling

Vortex flow data base associated with significant Reynolds number variation

Extending the VFE-2 data base for high-fidelity CFD applications (hybrid RANS/LES methods)The test case is currently addressed within the research activities GARTEUR AG49 and ATAAC.




Flow physics Flow physics –– CFD challenges CFD challenges (Re impact)

GARTEUR AG49:Scrutinizing Hybrid RANS/LES methodsFor Aerodynamic Applications

(Implicit LES TUM-AER)

Test case 2.2: VFE-2 delta wing

ATAAC – Advanced Turbulence Simulation for Aerodynamic Application Challenges

Test case: ST08 Delta wing with sharp leading edge (VFE-2)

Test case: AC06 Full aircraft with small aspect ratio wing (FA5)








Outline



VFEVFE--2 Model 2 Model –– cryogenic testingcryogenic testing

Model designed for cryogenic testing

ETW experiments



VFEVFE--2 Model 2 Model –– balance and stingbalance and sting

Balance: Wxxx suitable for ETW

ETW tail sting

ETW experiments



Test conditionsTest conditions

Flow parameterFlow parameter

• Ma ≈ 0.1 – 0.5 (load limit)

• Re ≈ 1 x 106 – 30 x 106

• α ≈ 0° – 35°

• V = const; Ma & Re variable

• q = const; T variable

• β = 0°

ETW experiments



Measured data and analysis Measured data and analysis

Aerodynamic characteristics …

Forces and moments

Development stages of dominant vortices …

Flowfield (PIV)

VFE-2KKK

(Courtesy R. Konrath)

ETW experiments







Outline



Partner nationsPartner nations

Consortium



Partner institutesPartner institutes

National Technical University of Athens, NTUA

WarsawUniversityof Technology

CzechAeronautical Research and Test Institute

Swedish DefenceResearch Agency

Consortium



Consortium Consortium –– linkslinks

GARTEUR AG49:CIRA, Cassidian, DLR, FOI, NLR, ONERA, TUM

National Technical University of Athens, NTUA

WarsawUniversityof Technology

CzechAeronautical Research and Test Institute

Consortium



Partners Partners –– TUMTUM--AER AER (Institute of Aerodynamics and Fluid Mechanics)

Proposal initiative / preparation

Data analysis and exploitation – nucleus for future projects

Importance of proposed work (commitment of partners)

Knowledge improvement of vortex physics

Experimental database for high-fidelity CFD verification

Contribution to improved transition/turbulence modeling

Fostering activities in vortex flow analysis and testing

Participation

Definition and support of test program and data reduction

Contribution to vortex flow measuring techniques



Partners Partners –– City University LondonCity University LondonBackground and expertise

Analysis of aerodynamic performance, flow control, aerodynamic optimization; in particular vortex flows and high-angle of attack aerodynamics Transition physics and turbulence modelingSubsonic wind tunnel facility; measurement techniques

Exploitation of data and results Re effects - enhancement of vortex flow analysis and modelingAnalysis of laminar-turbulence transition, shear-layer instabilities, vortex evolutionImproved understanding w.r.t vortex manipulation

Dr. S. Prince, Dr. D. Greenwell, Prof. C. AtkinsKey personnel (School of Engineering)

Consortium



Partners Partners –– FOI, KTHFOI, KTH (Swedish Defence Research Agency

Royal Institute of Technology)Background and expertiseAdvanced modeling of flow physics (turbulence and transition)Development of CFD methods and in-house CFD solver (EDGE)CFD analysis of air-vehicle aerodynamic performance, flow control, aero-acoustic noise, as well as for other multi-disciplinary aerodynamic applicationsHybrid RANS-LES simulations of vortex flows in conceptual studies of delta wing and fighter models

Exploitation of data and results Validation for development of advanced URANS and hybrid RANS-LES methodsValidation of turbulence-resolving simulations in modeling local laminar-turbulence transition, shear-layer instabilities, vortex formation, bursting and sheddingIn-depth understanding towards vortex flow control in relation to flight stabilityExtrapolation to higher Re-number flow conditions

Key personnel Dr. S.-H. Peng (FOI), Prof. A. Rizzi (KTH), Prof. C. Hirschel

Consortium



Partners Partners –– NTUANTUA (National Technical University of Athens)

Background and expertiseTesting of UAVs, airfoil sections, scaled wind turbine rotors, flow control concepts Flow predictions of vortical flows using various CFD models associated with fixed and rotary aircraft configurations Subsonic wind tunnel facility (M = 0.15); Force, PIV measurement techniques, …

Participation in EU projects

Exploitation of data and results

CFD based validation Support of PhD theses and post-doctoral research using data which will become available in this project

Key personnel (School of Mech. Eng., Fluids. Dept., Aero Lab.)Prof. K. Giannakoglou, Ass. Prof. S. Voutsinas, Ass. Prof. D. Mathoulakis

Consortium



Partners Partners –– VZLUVZLU (Aeronautical Research and Test Institute, CZ)

Background and expertisedistinguished research and test center; center of excellencesubstantial computational capacities and skillsoperation of several wind tunnel facilities (Mach 0.2 ÷ 3.5)

Exploitation of data and results verification of URANS CFD code EDGEimprovement of CFD application for high-agility A/C, high-α-regimepossible extension of in-house flight dynamics analysis

Key personnel Dr. Z. Patek, Dr. J. Fiala, Dr. P. Vrchota



Partners Partners –– Warsaw University of TechnologyWarsaw University of TechnologyBackground and expertise

Faculty of Power and Aero. Eng. – center of excellence for CFD

Development of CFD methods CFD analysis of aircraft aerodynamic performance

Exploitation of data and results

Widening of experience to be used in preparation of 2 Ph.D. thesesImprovement of research methodology and education for aerospace students

Key personnel Prof. Z. Goraj



Concluding remarksConcluding remarks

Research topic of high relevance for improving flow physics knowledge and high-fidelity numerical modeling

European research consortium established

W/T model and instrumentation available for cryogenic testing

Creating a sounded data base

Summary

Documents

Reynolds number influence on delta wing vortex · PDF fileTechnische Universität München 1 PD Dr.-Ing. C. Breitsamter, Dipl.-Ing. J.-U. Klar Reynolds number influence on delta wing