validation of star-ccm+ for external aerodynamics in the...

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

our 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

3

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

4

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

obtained excellent results compared with experiment.”

Matt Milne, QinetiQ

• 28 Years of experience

• Proven accuracy by industrial users

• Validated and tested at every stage

6

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)

7

RAE 2822

Coupled Solver Convergence

8

RAE 2822

STAR-CCM+ Validation

9

RAE 2822

NASA Code Validation

10

ONERA M6 Validation case

• University of Czestochowa, Poland

11

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

12

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

13

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.

14

ONERA M6 Tutorial

Volume Sources + Auto Remesh + Auto Solution Mapping….

15

High-Lift Multi-Element Airfoil

• STAR-CCM+ Advanced Hex Mesh (AKA Trimmed Cell)

• Implicit Coupled Solver @ M~0.2, Re=5e6

16


17


18


19


a=8.01

20


a=16.21

21


a=21.29

22

AIAA 3rd Drag Prediction Workshop

23

Wing-Body Configuration

With/Without Fairing

24

Mesh Generation: Define Volume Sources

“Cone” Volume Sources for Leading Edge Refinement

25


“Cone” Volume Sources for Trailing Edge Refinement

26


“Cone” Volume Sources for Wake Refinement

27


“Cone” Volume Sources for Tip and Tail Refinement

28


“Cone” Volume Sources for Shock Capture

And Fairing Refinement

29

Results

30

AIAA DPW3

Lift

31

AIAA DPW3

Drag Polar

32

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+

33

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.

34

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

35

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

36

Data Comparison

37

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)

38

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

39

Lift Coefficient

-1

0

1

2

3

4

5

-5 0 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

40

Drag Coefficient

0

0.5

1

1.5

2

2.5

3

-5 0 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

41

Lift to Drag Ratio

-1

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

4

-5 0 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

42

Pitching Moment

-4

-3

-2

-1

0

1

-5 0 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

43

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.

44

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)

45

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

46

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 0 5 10 15 20 25 30

Angle of Attack, degrees

Ax

ial

Fo

rce C

oe

ffic

ien

t

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

47


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 0 5 10 15 20 25 30


No

rma

l F

orc

e C

oe

ffic

ien

t

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

48


Pitching Moment - "Plus" Configuration

-10.00

-5.00

0.00

5.00

10.00

15.00

20.00

-5 0 5 10 15 20 25 30


Pit

ch

ing

Mo

me

nt

Co

eff

icie

nt

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

49

Axial Force - "Cross" Configuration

0.00

0.50

1.00

1.50

2.00

2.50

3.00

-5 0 5 10 15 20 25 30


Ax

ial

Fo

rce C

oe

ffic

ien

t

Run 1004

Star-CCM+ 0/0

Run 1044

Star-CCM+ 0/-20

Run 1037

Star-CCM+ 20/0

TANDEM CONTROL “×” CONFIGURATION

50

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 0 5 10 15 20 25 30


No

rma

l F

orc

e C

oe

ffic

ien

t

Run 1004

Star-CCM+ 0/0

Run 1044

Star-CCM+ 0/-20

Run 1037

Star-CCM+ 20/0


51

Pitching Moment - "Cross" Configuration

-10.00

-5.00

0.00

5.00

10.00

15.00

20.00

-5 0 5 10 15 20 25 30


Pit

ch

ing

Mo

me

nt

Co

eff

icie

nt

Run 1004

Star-CCM+ 0/0

Run 1044

Star-CCM+ 0/-20

Run 1037

Star-CCM+ 20/0


52

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

53

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 0 5 10 15 20 25 30 35


Ax

ial

Fo

rce /

Pit

ch

ing

Mo

me

nt

Co

eff

icie

nt

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 0 5 10 15 20 25 30 35


No

rma

l F

orc

e C

oe

ffic

ien

t

Normal Force, Exp. Normal Force, Star-CCM+

55

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 0 2 4 6 8 10 12

Sideslip Angle, degrees

Ro

llin

g M

om

en

t C

oe

ffic

ien

t

Exp., Alpha = 0 Star-CCM+, Alpha = 0 Exp., Alpha = 10 Star-CCM+, Alpha = 10

ELLIPTIC MISSILE

56

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

57

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

58

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

on 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.

59

Mach Contours @ Pr = 4.5, 3.5 and 2.0

Pr = 4.5 Pr = 2.0 Pr = 3.5

60

Shield Force @ Pr = 4.5, 3.5 and 2.0

Pr = 4.5 Pr = 2.0

Pr = 3.5

61

Shield Temperature @ Pr = 4.5, 3.5 and 2.0

Pr = 4.5 Pr = 2.0

Pr = 3.5

62

Shield Force v/s Pressure Ratio

Shield Force vs Pressure Ratio

0

50

100

150

200

250

300

350

400

450

500

0 1 2 3 4 5 6 7 8 9

Pressure Ratio (Pr)

To

tal

Sh

ield

Fo

rce (

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


• NACA RM-A7i30, 1948

• Wind Tunnel Tests

• Comparison of

– mesh types

– turbulence models

– physical models

– solvers

– codes

Airbus


Airbus


Flow vizualization with iso-surface of Q-criterium

ATS (Aeronautical Testing Service, Inc.)


• UW Capstone

• Design from RFP to

flying prototype

• Handling qualities and

noise research for a

supersonic class airliner

66



• 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



68



69

Airbus


• NACA RM-A7i30, 1948

• Wind Tunnel Tests

• Comparison of

– mesh types

– turbulence models

– physical models

– solvers

– codes

Airbus


Airbus


Flow vizualization with iso-surface of Q-criterium



• UW Capstone

• Design from RFP to

flying prototype

• Handling qualities and

noise research for a

supersonic class airliner

73



• 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



75



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 0.00613 0

-2 0.005834 -0.21891

-4 0.00644 -0.43445

-6 0.007199 -0.6516

-8 0.010158 -0.84582

Results

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