Reynolds number influence on delta wing vortex flows

Transcrição

Technische Universität München
Reynolds number influence on
delta wing vortex flows
TUM-AER project
Outline
Background and expertise
Objectives and exploitation
ETW experiments – model & instrumentation
Partners – consortium
PD Dr.-Ing. C. Breitsamter,
Dipl.-Ing. J.-U. Klar
1
Outline
2
Flow physics – basics
Evolution of large scale vortices …
determine lift characteristics, maneuver capabilities
and stability
α
Main parameters
w
Incident and surface flow
U∞
Angle of attack α
Boundary layer
(laminar / turbulent)
φ
Geometry
Wing sweep φ
(planform)
rN
Leading-edge radius rN
(airfoil)
Background
3
Flow physics – basics
Vortex development depend on leading-edge sweep φ and angle of attack α
α [°]
40
35
30
Thin,
Thin, planar
planar wings;
wings;
sharp
sharp leading–edge
leading–edge
αmax
25
20
15
4:
Vortex
bursting
over the
wing
3:
Span–wise
fixed vortex
φW
3
α
4
2:
Fully developed
vortex, moving
inboard
αBursting
(trailing–edge)
2
α
turbulent
laminar
10
1:
Vortex
formation
∆α
5
turbulent
α
1
laminar
0
50
55
60
65
70
75
Background
80
85
φ [°]
4
Flow physics – Re influence (secondary separation)
Separation line of secondary vortex
Re x =
U∞ x
ν
x
y
Laminar
region
–CP
y
Transition
Upper- / lower side:
Turbulent
region
–CP
Re > Re crit ,upper
Laminar / laminar :
Rex < 0.9 x 106 = Recrit,upper
y
–CP
Turbulent / laminar :
0.9 x 106 < Rex < 1.9 x 106
Re > Re crit ,lower
Turbulent / turbulent :
Rex > 1.9 x 106 = Recrit,lower
y
Background
5
VFE-2
(RTO-AVT-113, RTO-AVT-183)
Expertise
6
b = 0.933 cr
VFE-2 configuration – Geometry
φ = 65°
Rounded LE
Sharp LE
cr
t = 0.034 cr
0.15 cr
0.10 cr
r/lµ = 0.15 %
Expertise
7
VFE-2 config. – TUM–AER wind tunnel model
Sharp leading-edge
Rounded leading-edge
r/lµ = 0.0015
Expertise
8
VFE-2 config. – TUM–AER wind tunnel model
root chord
cr
0.980 m
wing span
b = 2s
0.914 m
wing area
F
0.448 m2
mean aerodynamic
chord
lµ
2/3 cr
aspect ratio
Λ
1.865
leading edge sweep
φ
65°
Expertise
9
φ = 65°
0.2
0.4
0.6
0.8 0.95
177 pressure pos.:
diam. 0.3 mm
cr
5 chord stations
t = 0.034 cr
0.15 cr
b = 0.933 cr
VFE-2 config. – TUM–AER model instrumentation
0.10 cr
133 steady sensors (PSI)
44 unsteady sensors (Kulites)
10
Laser light sheet flow visualization
Burst leading–edge vortex; α = 30°:
x/cr = 1.10
0.20
0.40
0.60
0.80
0.95
Expertise
11
Laser light sheet flow visualization
Fully developed leading–edge vortex; α = 18°:
Sharp leading edge
Rounded leading edge
Expertise
12
Flow field – mean velocity
Partly developed leading–edge vortex; α = 13°:
x/cr = 0.2, 0.4, 0.6, 0.8, and 0.95:
Expertise
13
Flow field – turbulence intensity
Partly developed leading–edge vortex; α = 13°:
x/c
x/crr == 0.4
0.4
x/c
x/crr == 0.6
0.6
x/c
x/crr == 0.8
0.8
uurms
/U ∞
rms/U∞
Expertise
14
Flow field – turbulence intensity
Burst leading–edge vortex; α = 23°:
x/c
x/crr == 0.4
0.4
x/c
x/crr == 0.6
0.6
x/c
x/crr == 0.8
0.8
uurms
/U ∞
rms/U∞
Expertise
15
Surface pressure – turbulence intensity
Re
Re == 2.0
2.0 xx 10
1066
αα == 23°
23°
16
Complex flow topology – Re 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
17
Flow physics – Re influence
U∞ M = 0.14
Topology of
Re = 2.0 x 106 vortex system
α = 13°
Laminar
separation
Inboard vortex
Separation
Attachment
Turbulent
separation
Primary vortex
Separation
Attachment
Secondary vortex
Separation
Attachment
Oil flow
Expertise
18
VFE-2
delta wing
KKK tests (T: 240 K – 150 K)
Ma = 0.05 – 0.16
M = 0.14
Re = 2.0 x 106
α = 13°
DLR – TSP
TUM – Oil flow
(Courtesy R. Konrath)
Re = 1 x 106 – 6 x 106
α = 5° – 28°
Expertise
19
Outline
20
¾ Separating shear layer
φ
¾ Vortex core (fully developed / bursting)
¾ Boundary layer – secondary separation
α = 25.0°
u ′2 U ∞
0.28
U∞
0.20
α = 30.0°
0.10
0.02
Associated characteristic instabilities
φ = 76°
21
Multiple
vortex
system
Re = 2.0 x 106
α = 18°
Re = const.
α
Laminar
separation
Turbulent
separation
22
Rounded
leading edge
α = 18°
Re = 1·106
23
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.
24
Flow physics – CFD challenges (Re impact)
GARTEUR AG49:
Scrutinizing Hybrid RANS/LES methods
For Aerodynamic Applications
Test case 2.2: VFE-2 delta wing
ATAAC – Advanced Turbulence Simulation
for Aerodynamic Application Challenges
(Implicit LES
TUM-AER)
Test case: ST08 Delta wing with sharp leading edge (VFE-2)
Test case: AC06 Full aircraft with small aspect ratio wing (FA5)
25
Outline
26
VFE-2 Model – cryogenic testing
Model designed for cryogenic testing
ETW experiments
27
VFE-2 Model – balance and sting
¾ Balance: Wxxx suitable for ETW
¾ ETW tail sting
ETW experiments
28
Test conditions
Flow 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
29
Measured data and analysis
Aerodynamic characteristics …
Forces and moments
Development stages of dominant vortices …
Flowfield (PIV)
VFE-2
KKK
(Courtesy R. Konrath)
ETW experiments
30
Outline
31
Partner nations
Consortium
32
Partner institutes
National
Technical
University of
Athens, NTUA
Warsaw
University
of Technology
Czech
Aeronautical
Research and
Test Institute
Swedish
Defence
Research
Agency
Consortium
33
Consortium – links
National
Technical
University of
Athens, NTUA
Warsaw
University
of Technology
Czech
Aeronautical
Research and
Test Institute
GARTEUR AG49:
CIRA, Cassidian, DLR,
FOI, NLR, ONERA, TUM
Consortium
34
Partners – TUM-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
35
Partners – City University London
¾ Analysis of aerodynamic performance, flow control, aerodynamic optimization;
in particular vortex flows and high-angle of attack aerodynamics
¾ Transition physics and turbulence modeling
¾ Subsonic wind tunnel facility; measurement techniques
Exploitation of data and results
¾ Re effects - enhancement of vortex flow analysis and modeling
¾ Analysis of laminar-turbulence transition, shear-layer instabilities,
vortex evolution
¾ Improved understanding w.r.t vortex manipulation
Key personnel (School of Engineering)
Dr. S. Prince, Dr. D. Greenwell, Prof. C. Atkins
Consortium
36
Partners – FOI, KTH (Swedish Defence Research Agency
Royal Institute of Technology)
¾ Advanced modeling of flow physics (turbulence and transition)
¾ Development of CFD methods and in-house CFD solver (EDGE)
¾ CFD analysis of air-vehicle aerodynamic performance, flow control,
aero-acoustic noise, as well as for other multi-disciplinary aerodynamic applications
¾ Hybrid RANS-LES simulations of vortex flows in conceptual studies of
delta wing and fighter models
¾ Validation for development of advanced URANS and hybrid RANS-LES methods
¾ Validation of turbulence-resolving simulations in modeling local laminar-turbulence
transition, shear-layer instabilities, vortex formation, bursting and shedding
¾ In-depth understanding towards vortex flow control in relation to flight stability
¾ Extrapolation to higher Re-number flow conditions
Key personnel
Dr. S.-H. Peng (FOI), Prof. A. Rizzi (KTH), Prof. C. Hirschel
Consortium
37
Partners – NTUA (National Technical University of Athens)
¾ Testing of UAVs, airfoil sections, scaled wind turbine rotors,
flow control concepts
¾ Flow predictions of vortical flows using various CFD models
associated with fixed and rotary aircraft configurations
¾ Subsonic wind tunnel facility (M = 0.15);
Force, PIV measurement techniques, …
Participation in EU projects
¾ CFD based validation
¾ 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
38
Partners – VZLU (Aeronautical Research and Test Institute, CZ)
¾ distinguished research and test center; center of excellence
¾ substantial computational capacities and skills
¾ operation of several wind tunnel facilities (Mach 0.2 ÷ 3.5)
¾ verification of URANS CFD code EDGE
¾ improvement of CFD application for high-agility A/C, high-α-regime
¾ possible extension of in-house flight dynamics analysis
Key personnel
Dr. Z. Patek, Dr. J. Fiala, Dr. P. Vrchota
39
Partners – Warsaw University of Technology
¾ Faculty of Power and Aero. Eng. – center of excellence for CFD
¾ Development of CFD methods
¾ CFD analysis of aircraft aerodynamic performance
¾ Widening of experience to be used in preparation of 2 Ph.D. theses
¾ Improvement of research methodology and education for aerospace
students
Key personnel
Prof. Z. Goraj
40
Concluding 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
41

Reynolds number influence on delta wing vortex flows

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