Validation of STAR-CCM+ for External Aerodynamics in the Aerospace - - PowerPoint PPT Presentation

Validation of STAR-CCM+ for External Aerodynamics in the Aerospace Industry

CD-adapco‟s Commitment To The Aerospace & Defense Industry

“CD-adapco is committed to the aerospace industry. I can assure

• ur friends in the aerospace engineering community that we will

continue to leverage our experience and expertise in order to provide solutions that have the flexibility to accurately solve this industry's broad range of flow, thermal, and stress problems with unprecedented efficiency.” Steve MacDonald, CD-adapco President

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What Do You Expect from Your CAE Software?

• Flexibility

» Meshing – Hex, Tet, Poly » Solvers – Segregated, Implicit/Explicit Coupled

• Experience

» Highly trained and experienced staff in every facet of the company

• Efficiency

» Leader in software development for HPC, mesh technology, etc.

• Accuracy

» RAE 2822 » ONERA M6 » Multi-Element Airfoil » Drag Prediction Workshop (Wing-Body) » Joint Common Missile (Lockheed Martin Missiles and Fire Control) » Missile Validation Cases (NAVAIR China Lake) » Impinging Jet & Supersonic Nozzle

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What Do You Expect from Your CAE Software?

• Flexibility

» Processes – CAD-Embedded, Surface Wrapping, etc. » Meshing – Hex, Tet, Poly » Solvers – Segregated, Implicit/Explicit Coupled

• Experience

» Highly trained and experienced staff in every facet of the company

• Efficiency

» Leader in software development for HPC, mesh technology, etc.

• Accuracy

» Validated by 30+ years of use & development » Jointly validate by CD-adapco and by our customers

Accuracy For Aerospace Applications

“Over the past years, we have used STAR-CCM+ to predict the aerodynamic performance of both commercial and military aircraft. In particular, we ran cases from the 2nd Drag Prediction Workshop and

• btained excellent results compared with experiment.”

Matt Milne, QinetiQ

• 28 Years of experience
• Proven accuracy by industrial users
• Validated and tested at every stage

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RAE 2822 Case Definition

• Mesh: 24,576 cells (369x65 structured C-grid)
• M=0.729, a = 2.31, Re=6.5e6
• Coupled implicit solver (2nd order)

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RAE 2822 Coupled Solver Convergence

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RAE 2822 STAR-CCM+ Validation

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RAE 2822 NASA Code Validation

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ONERA M6 Validation case

• University of Czestochowa, Poland

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Experimental data

Two cases – angle of attack 3.03° and 6.06°. Mach 0.839 Cp values on 7 sections across wing.

Section A Section G

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STAR-CCM+ vs Experiment 3° case - Section C

• For 3° case, excellent results for NASA mesh:

Polyhedral mesh not run.

• Section C – k-Epsilon – NASA hexa mesh

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STAR-CCM+ vs Experiment 6° case - Section F

• For „difficult‟ 6° case, NASA mesh performs well on in-

board sections but poorly on sections close to wing tip

• However, polyhedral mesh gives excellent results for

all sections.

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ONERA M6 Tutorial

Volume Sources + Auto Remesh + Auto Solution Mapping….

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High-Lift Multi-Element Airfoil

• STAR-CCM+ Advanced Hex Mesh (AKA Trimmed Cell)
• Implicit Coupled Solver @ M~0.2, Re=5e6

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High-Lift Multi-Element Airfoil

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High-Lift Multi-Element Airfoil

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High-Lift Multi-Element Airfoil

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High-Lift Multi-Element Airfoil

a=8.01

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High-Lift Multi-Element Airfoil

a=16.21

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High-Lift Multi-Element Airfoil

a=21.29

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AIAA 3rd Drag Prediction Workshop

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Wing-Body Configuration With/Without Fairing

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Mesh Generation: Define Volume Sources

“Cone” Volume Sources for Leading Edge Refinement

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Mesh Generation: Define Volume Sources

“Cone” Volume Sources for Trailing Edge Refinement

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Mesh Generation: Define Volume Sources

“Cone” Volume Sources for Wake Refinement

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Mesh Generation: Define Volume Sources

“Cone” Volume Sources for Tip and Tail Refinement

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Mesh Generation: Define Volume Sources

“Cone” Volume Sources for Shock Capture And Fairing Refinement

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Results

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AIAA DPW3 Lift

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AIAA DPW3 Drag Polar

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STAR-CCM+: Validated for Drag Prediction

• Flexible and easy CAD import/integration
• Flexible, powerful and easy mesh generation
• Fast, accurate solutions that have been validated

Drag Prediction Workshop 3 Wing-Body Configuration

0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.016 0.018 0.020 0.022 0.024 0.026 0.028 0.030 0.032 0.034 0.036 0.038 0.040 Cd Cl Experiment STAR-CCM+

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Transonic Drag Rise Validation Case

• The objective was validate STAR-CCM+ simulation

methodologies for a zero-lift drag rise as a known body passes through mach 1.

• The input surfaces and boundary conditions were

generated based on the data provided in NACA paper 1160.

• STAR-CCM+ preformed very well for all speeds tested.

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Transonic Drag Rise Validation Case

• The focus of this set of simulations

was to accurately capture the drag rise as the RM-10 passes through the sound barrier

• Speeds from Mach number 0.7-1.2

were chosen

• STAR-CCM+ was used to mesh and

solve the problem

• Because the body is in a zero lift

configuration it was only necessary to model 90 degrees of the body

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STAR-CCM+ Automated Hex Mesh

• A hex-dominant mesh was chosen to discretize the

volume

• Near wall cells were body fitted (prism layer) cells in 12

layers with varying thickness depending on location

• The final volume mesh contained 2.1 Million Cells

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Data Comparison

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LMMFC Orlando STAR-CCM+ Validation Case

• Joint Common Missile (JCM)

–

Basic lift, drag, and pitching moment performance

–

Evaluated against wind tunnel data

»

Mach: 0.50, 0.75, 1.25

» Alpha: 0 – 20 degrees »

Beta / Phi: 0

• Study done jointly by LMMFC and CD-adapco

(Thanks to Glenn Gebert and Deryl Snyder at LMMFC)

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Grid / Computational Domain

• CAD geometry imported in IGES

format

»

Surface wrapper / remesher used to clean up geometry

»

Complex protrusions, straps, mounts, holes, etc.

• Polyhedral volume mesh

»

Volume sources used to refine mesh in critical areas

»

5 rows of prism layers near the walls

»

Wall y+ ~ 30 – 90

»

Approximately 3 million cells overall

• Boundary conditions

»

No-slip walls with „All y+ Wall Treatment‟ boundary conditions at the walls

»

Freestream conditions applied 250 diameters away from missile

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Lift Coefficient

• 1

1 2 3 4 5

• 5

5 10 15 20 25 Alpha (deg) CL

Mach 0.50 StarCCM+ Mach 0.50 SplitFlow Mach 0.50 Tunnel Mach 0.75 StarCCM+ Mach 0.75 SplitFlow Mach 0.75 Tunnel Mach 1.25 StarCCM+ Mach 1.25 SplitFlow Mach 1.25 Tunnel

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Drag Coefficient

0.5 1 1.5 2 2.5 3

• 5

5 10 15 20 25 Alpha (deg) CD

Mach 0.50 StarCCM+ Mach 0.50 SplitFlow Mach 0.50 Tunnel Mach 0.75 StarCCM+ Mach 0.75 SplitFlow Mach 0.75 Tunnel Mach 1.25 StarCCM+ Mach 1.25 SplitFlow Mach 1.25 Tunnel

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Lift to Drag Ratio

• 1
• 0.5

0.5 1 1.5 2 2.5 3 3.5 4

• 5

5 10 15 20 25 Alpha (deg) L/D

Mach 0.50 StarCCM+ Mach 0.50 SplitFlow Mach 0.50 Tunnel Mach 0.75 StarCCM+ Mach 0.75 SplitFlow Mach 0.75 Tunnel Mach 1.25 StarCCM+ Mach 1.25 SplitFlow Mach 1.25 Tunnel

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Pitching Moment

• 4
• 3
• 2
• 1

1

• 5

5 10 15 20 25 Alpha (deg) Cm

Mach 0.50 StarCCM+ Mach 0.50 SplitFlow Mach 0.50 Tunnel Mach 0.75 StarCCM+ Mach 0.75 SplitFlow Mach 0.75 Tunnel Mach 1.25 StarCCM+ Mach 1.25 SplitFlow Mach 1.25 Tunnel

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LMMFC Conclusions

• Results

– STAR-CCM+ predicted lift forces comparable to that of

Splitflow: generally within 5%

» Under-predicted at low Mach numbers – STAR-CCM+ predicted drag forces significantly better than

Splitflow: generally within 5% (within 1.5% @ Mach 1.25)

– STAR-CCM+ predicted pitching moments significantly better

than Splitflow: trim angle generally within 1 degree

• General Comments from LMMFC

– STAR-CCM+ is now the standard tool for refined analyses,

drag-critical, internal/external flows, conjugate heat transfer, etc.

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NAVAIR China Lake Validation Studies

• Missile external aerodynamics
• Two public domain cases
• Independent validation (no involvement from CD-

adapco)

• Data and statements supplied directly by Ron Shultz

and Peter Cross from NAVAIR China Lake (US Navy)

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STAR-CCM+ RUN METRICS

• TANDEM CONTROL MISSILE IN “PLUS” CONFIGURATION

–

HALF MODEL

–

APPROXIMATELY 1.5M CELLS

–

MESHING TIME

»

<5 MINUTES SURFACE MESH

»

~30 MINUTES VOLUME MESH

–

SOLUTION TIME

»

~3 HOURS PER ALPHA (~600-700 ITERATIONS)

»

FULL ALPHA SWEEP IN <48 HOURS

• TANDEM CONTROL MISSILE IN “CROSS” CONFIGURATION

–

HALF MODEL

–

APPROXIMATELY 2.0M CELLS

–

MESHING TIME

»

<5 MINUTES SURFACE MESH

»

~50 MINUTES VOLUME MESH

–

SOLUTION TIME

»

~6 HOURS PER ALPHA (~1200 ITERATIONS)

»

FULL ALPHA SWEEP IN <72 HOURS

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TANDEM CONTROL “+” CONFIGURATION

Axial Force - "Plus" Configuration

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80

• 5

5 10 15 20 25 30 Angle of Attack, degrees Axial Force Coefficient Run 47 Run 1003 Star-CCM+ 0/0 Run 1015 Star-CCM+ 0/-20 Run 1010 Star-CCM+ 20/0 Run 1046 Star-CCM+ 20/-20 Run 53 Star-CCM+ 10/10

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TANDEM CONTROL “+” CONFIGURATION

Normal Force - "Plus" Configuration

• 4.00
• 2.00

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

• 5

5 10 15 20 25 30 Angle of Attack, degrees Normal Force Coefficient Run 47 Run 1003 Star-CCM+ 0/0 Run 1015 Star-CCM+ 0/-20 Run 1010 Star-CCM+ 20/0 Run 1046 Star-CCM+ 20/-20 Run 53 Star-CCM+ 10/10

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TANDEM CONTROL “+” CONFIGURATION

Pitching Moment - "Plus" Configuration

• 10.00
• 5.00

0.00 5.00 10.00 15.00 20.00

• 5

5 10 15 20 25 30 Angle of Attack, degrees Pitching Moment Coefficient Run 47 Run 1003 Star-CCM+ 0/0 Run 1015 Star-CCM+ 0/-20 Run 1010 Star-CCM+ 20/0 Run 1046 Star-CCM+ 20/-20 Run 53 Star-CCM+ 10/10

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Axial Force - "Cross" Configuration

0.00 0.50 1.00 1.50 2.00 2.50 3.00

• 5

5 10 15 20 25 30 Angle of Attack, degrees Axial Force Coefficient Run 1004 Star-CCM+ 0/0 Run 1044 Star-CCM+ 0/-20 Run 1037 Star-CCM+ 20/0

TANDEM CONTROL “×” CONFIGURATION

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Normal Force - "Cross" Configuration

• 4.00
• 2.00

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

• 5

5 10 15 20 25 30 Angle of Attack, degrees Normal Force Coefficient Run 1004 Star-CCM+ 0/0 Run 1044 Star-CCM+ 0/-20 Run 1037 Star-CCM+ 20/0

TANDEM CONTROL “×” CONFIGURATION

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Pitching Moment - "Cross" Configuration

• 10.00
• 5.00

0.00 5.00 10.00 15.00 20.00

• 5

5 10 15 20 25 30 Angle of Attack, degrees Pitching Moment Coefficient Run 1004 Star-CCM+ 0/0 Run 1044 Star-CCM+ 0/-20 Run 1037 Star-CCM+ 20/0

TANDEM CONTROL “×” CONFIGURATION

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T.C.M. RESULTS – STAR-CCM+

• AXIAL FORCE

– TRENDS APPEAR TO BE CAPTURED WITH REASONABLE

ACCURACY

• NORMAL FORCE

– EXTREMELY GOOD CORRELATION BETWEEN STAR-CCM+

RESULTS AND EXPERIMENTAL DATA

• PITCHING MOMENT

– REASONABLY GOOD COMPARISON BETWEEN STAR-CCM+

RESULTS AND EXPERIMENTAL DATA

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Axial Force and Pitching Moment - Elliptic Missile - Beta = 0

• 0.60
• 0.50
• 0.40
• 0.30
• 0.20
• 0.10

0.00 0.10 0.20 0.30

• 5

5 10 15 20 25 30 35 Angle of Attack, degrees Axial Force / Pitching Moment Coefficient Axial Force, Exp. Axial Force, Star-CCM+ Pitching Moment, Exp. Pitching Moment, Star-CCM+ Pitching Moment, Xref 0.16" Aft

ELLIPTIC MISSILE

54

ELLIPTIC MISSILE

Normal Force - Elliptic Missile - Beta = 0

• 2.00

0.00 2.00 4.00 6.00 8.00 10.00 12.00

• 5

5 10 15 20 25 30 35 Angle of Attack, degrees Normal Force Coefficient Normal Force, Exp. Normal Force, Star-CCM+

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Rolling Moment - Elliptic Missile

• 0.600
• 0.500
• 0.400
• 0.300
• 0.200
• 0.100

0.000 0.100 0.200

• 6
• 4
• 2

2 4 6 8 10 12 Sideslip Angle, degrees Rolling Moment Coefficient Exp., Alpha = 0 Star-CCM+, Alpha = 0 Exp., Alpha = 10 Star-CCM+, Alpha = 10

ELLIPTIC MISSILE

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E.M. RESULTS – STAR-CCM+

• AXIAL FORCE

–

TRENDS APPEAR TO BE CAPTURED WITH REASONABLE ACCURACY

• NORMAL FORCE

–

EXTREMELY GOOD CORRELATION BETWEEN STAR-CCM+ RESULTS AND EXPERIMENTAL DATA

• PITCHING MOMENT

–

POOR COMPARISON BETWEEN STAR-CCM+ RESULTS AND EXPERIMENTAL DATA

–

TRENDS SHOW SOME SIMILARITIES

–

CAN BE EXPLAINED BY SHIFT IN MOMENT REFERENCE POINT

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Impinging Jet Analysis

• Physics

–

Axisymmetric

–

Steady State

–

Ideal Gas

–

Coupled Flow + Coupled Energy

–

RANS + K-O SST Menter Turbulence Model

• Shield distance to Nozzle Diameter Ratio (z/d)

–

8.0

• Pressure Ratios Tested

–

7.8, 4.5, 3.5 and 2.0

• Stagnation Pressures

–

100, 51.45, 36.75,14.7 (psig)

• Stagnation Temperature

–

1026 and 882 R

• Ambient Pressure

–

14.7 psi

• Ambient Temperature

–

540 R

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Impinging Jet References

• J.G. Love et al., “Experimental Investigations of the Heat Transfer

Charactristics of Impinging Jets”, AIAA Paper 93-5018, 1994.

• Messersmith, N.L. and Murthy, S.N.B., “Outline of a Test Facility for

Combustor Burn-Through Protection Shield”, AIAA paper 95-0731, 1995.

• Messersmith, N.L. and Murthy, S.N.B., “Thermal and Mechanical Loading
• n a Fire Protection Shield Dua to a Burn-Through”, AGARD 88th

Symposium of the Propulsion and Energetics Panel on aircraft Fire Safety, Dresden, Germany, 1996.

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Mach Contours @ Pr = 4.5, 3.5 and 2.0

Pr = 4.5 Pr = 2.0 Pr = 3.5

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Shield Force @ Pr = 4.5, 3.5 and 2.0

Pr = 4.5 Pr = 2.0 Pr = 3.5

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Shield Temperature @ Pr = 4.5, 3.5 and 2.0

Pr = 4.5 Pr = 2.0 Pr = 3.5

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Shield Force v/s Pressure Ratio

Shield Force vs Pressure Ratio

50 100 150 200 250 300 350 400 450 500 1 2 3 4 5 6 7 8 9 Pressure Ratio (Pr) Total Shield Force (N) STARCCM+ Experiment

Experimental Data: Figure 5, Thermal And Mechanical Loading On a Fire Protection Shield Due To A

Combustor Burn-Through, N.L. Messersmith and S.N.B. Murthy

Airbus STAR-CCM+ Validation Case

• NACA RM-A7i30, 1948
• Wind Tunnel Tests
• Comparison of

– mesh types – turbulence models – physical models – solvers – codes

Page 63

Airbus STAR-CCM+ Validation Case

Page 64

Airbus STAR-CCM+ Validation Case

Page 65

Flow vizualization with iso- surface of Q-criterium

ATS (Aeronautical Testing Service, Inc.) STAR-CCM+ Validation Case

• UW Capstone
• Design from RFP to

flying prototype

• Handling qualities and

noise research for a supersonic class airliner

66

ATS (Aeronautical Testing Service, Inc.) STAR-CCM+ Validation Case

• Undergraduate students with no CAD / CFD experience
• Development cycle of 6 months
• 4 workstations of 4GB RAM each
• STAR-CCM+ models limited to ≈ 4 millions cells max
• Access to 96 Core Linux cluster at ATS
• CFD data available on the first day of wind tunnel

testing

67

ATS (Aeronautical Testing Service, Inc.) STAR-CCM+ Validation Case

68

ATS (Aeronautical Testing Service, Inc.) STAR-CCM+ Validation Case

69

Airbus STAR-CCM+ Validation Case

• NACA RM-A7i30, 1948
• Wind Tunnel Tests
• Comparison of

– mesh types – turbulence models – physical models – solvers – codes

Page 70

Airbus STAR-CCM+ Validation Case

Page 71

Airbus STAR-CCM+ Validation Case

Page 72

Flow vizualization with iso- surface of Q-criterium

ATS (Aeronautical Testing Service, Inc.) STAR-CCM+ Validation Case

• UW Capstone
• Design from RFP to

flying prototype

• Handling qualities and

noise research for a supersonic class airliner

73

ATS (Aeronautical Testing Service, Inc.) STAR-CCM+ Validation Case

• Undergraduate students with no CAD / CFD experience
• Development cycle of 6 months
• 4 workstations of 4GB RAM each
• STAR-CCM+ models limited to ≈ 4 millions cells max
• Access to 96 Core Linux cluster at ATS
• CFD data available on the first day of wind tunnel

testing

74

ATS (Aeronautical Testing Service, Inc.) STAR-CCM+ Validation Case

75

ATS (Aeronautical Testing Service, Inc.) STAR-CCM+ Validation Case

76

Lift and Drag Prediction for Naca 0012

77

78

• Imported NACA 0012 Geometry into STAR CCM+
• Created domain around the model
• Volume meshed
• Converted domain to 2D
• Set up boundary conditions
• Run

Workflow

79

• Volume Mesh Settings:

– Models: Trimmer – Near wall prism thickness: 1e-6 m – # Prism layers: 48 – Total Prism Layer Thickness: 0.025 m – Additional Options: Volume Shapes and Trimmer Wake

Refinement

• Volume mesh was converted into 2D resulting in

151966 cells.

Volume Mesh

• Mesh:

80

Mesh

81

• Wall y+ plot

Mesh

82

• The following Physics models have

been used:

• Given:

– Re = 3E+06..assume T = 300K...M =

0.1353 ; u = 47.04 m/s

Note: All solver settings are at default.

Physics

Results

83

α = 0 deg α = 2 deg α = 4 deg α = 6 deg

Results

84

α = 10 deg α = 12 deg α = 14 deg α = 16 deg

85

• Results:

Angle Cd Cl 8 0.01047 0.8454 6 0.00758 0.64953 4 0.00655 0.4341 2 0.0058 0.2191 0.00613

• 2

0.005834 -0.21891

• 4

0.00644 -0.43445

• 6

0.007199 -0.6516

• 8

0.010158 -0.84582

Results

86