scott a. berry [email protected] note that this is...

Scott A. [email protected]

steves

Text Box

Note that this is Scott Berry's opinion only, as of 2003. Other perspectives should also be taken into account.

Vehicle Design ProcessAerothermodynamicsAerothermodynamicsAerothermodynamics

Synergistic Approach for Aerothermodynamic InformationSynergistic Approach forSynergistic Approach for Aerothermodynamic Aerothermodynamic InformationInformationGround – Based

TestingComputational

Fluid Dynamics (CFD)

Hypersonic wind tunnels Navier Stokes solvers

OptimumAerothermodynamic Data

Safe, reliable,successful flight

Tried and proven Rapidly improving

Can have best propulsion, structures, materials, avionics, GNδC, etc.; but if have poor aerothermodynamics, all may be nullified

+ =

Basic questionsWould you fly on access-to-space vehicle if:

Designed and flown on: Wind tunnel data only?CFD data only?

and/or Aerothermodynamics taken for granted; relegated to secondary technology?

20-InchMach 6

Air

31-InchMach 10

Air

20-InchMach 13-18Real Gas

Simulation

NASA Centers performing aerothermodynamic studiesNation’s conventional hypersonic wind tunnels for aerothermodynamic testingNASA Centers performing aerothermodynamic studiesNation’s conventional hypersonic wind tunnels for aerothermodynamic testing

AmesResearch Center

(Non-metallicthermal protection

system)

AmesResearch Center

(Non-metallicthermal protection

system)

Dryden Flight Research Center

Dryden Flight Research Center

Johnson Space Center(Crewed Aerospace Vehicles)

Johnson Space Center(Crewed Aerospace Vehicles) Marshall Space Flight

CenterMarshall Space Flight

Center

AEDC Tunnel 9AEDC Tunnel 9

Arnold Engineering andDevelopment Center(AEDC) Tunnels B, C

Arnold Engineering andDevelopment Center(AEDC) Tunnels B, C

Langley Research CenterLangley Research Center

Langley Aerothermodynamics Laboratory (LAL)Langley Aerothermodynamics Laboratory (LAL)

15-InchMach 6

Hi Temp.Air

National Aerothermodynamic Capability

Aerothermodynamics Branch (AB) Personnel

60 and above

31 FTE CS AST

Eligible forretirement

Education

MS

BS

PhD

30 35 40 45 50 55Years of age

1210

86420

AST

Age distribution

Disciplines

1086420

AST

below 30

DSMC

Engr

. Cod

es CFD

Aero

Facil

itiesAe

rohe

ating

Leve

l IIIs

etc.

Manag

ers

Computa-tionalists

(11)

Experi-mentalists

(10)

Administra-tive/other

(10)

steves

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20-Inch Mach 6 Air Tunnel

Test ConditionsM∞ = 6

Re∞ = 0.5 - 8.0E6 /ft

Pt, 1 = 30 - 475 psia

Tt, 1 = 410 - 475°F

Test Gas - Air, γ∞ = 1.4

Run times up to 15 min.

8-10 Runs per Day


Re∞ = 0.5 - 8.0E6 /ft

Pt, 1 = 30 - 475 psia

Tt, 1 = 410 - 475°F


Run times up to 15 min.

8-10 Runs per Day

Features• Ideally suited for both parametric and benchmark aerodynamic,

aerothermodynamic and fluid dynamic studies

• Synergism with 31-Inch Mach 10 Air Tunnel allows assessment of

compressibility effects at constant Re∞ and γ∞

• Synergism with 20-Inch Mach 6 CF4 Tunnel allows determination of real gas aerodynamic effects at constant M∞ and Re∞

Features• Ideally suited for both parametric and benchmark aerodynamic,

aerothermodynamic and fluid dynamic studies

• Synergism with 31-Inch Mach 10 Air Tunnel allows assessment of

compressibility effects at constant Re∞ and γ∞

• Synergism with 20-Inch Mach 6 CF4 Tunnel allows determination of real gas aerodynamic effects at constant M∞ and Re∞

31-Inch Mach 10 Air Tunnel


Re∞ = 0.25 - 2.2E6 /ft

Pt, 1 =125 -1450 psia

Tt, 1 = 1350οF


Run time 120 sec.

8-10 Runs per Day


Re∞ = 0.25 - 2.2E6 /ft

Pt, 1 =125 -1450 psia

Tt, 1 = 1350οF


Run time 120 sec.

8-10 Runs per Day

Features• Uniform, clean flow; three-dimensional, contoured, water-cooled nozzle and five micron

particle filter to remove flow contaminates• Ideally suited for both parametric and benchmark aerodynamic, aerothermodynamic and

fluid dynamic studies• Synergism with 20-Inch Mach 6 Air Tunnel allows assessment of compressibility effects

at constant Re∞ and γ∞

Features• Uniform, clean flow; three-dimensional, contoured, water-cooled nozzle and five micron

particle filter to remove flow contaminates• Ideally suited for both parametric and benchmark aerodynamic, aerothermodynamic and

fluid dynamic studies• Synergism with 20-Inch Mach 6 Air Tunnel allows assessment of compressibility effects

at constant Re∞ and γ∞

20-Inch Mach 6 CF4 Tunnel

Test ConditionsM∞ = 6 (13-18 Simulation)

Re∞ = 0.05 - 0.7E6/ft

Pt,1=100 - 2000 psia

Tt,1 = 640 - 1000°F

Test Gas - CF4, γ∞ = 1.2

Run times - 20 sec.

4-6 Runs per Day

Test ConditionsM∞ = 6 (13-18 Simulation)

Re∞ = 0.05 - 0.7E6/ft

Pt,1=100 - 2000 psia

Tt,1 = 640 - 1000°F

Test Gas - CF4, γ∞ = 1.2

Run times - 20 sec.

4-6 Runs per Day

Features• Only operational, conventional-type hypersonic facility in this country

which simulates dissociative real-gas phenomena associated with hypersonic flight

• Synergism with 20-Inch Mach 6 Air Tunnel allows determination of real gas aerodynamic effects at constant M∞ and Re∞

• Evaluating use of CO2 as a test gas to support planetary missions

Features• Only operational, conventional-type hypersonic facility in this country

which simulates dissociative real-gas phenomena associated with hypersonic flight

• Synergism with 20-Inch Mach 6 Air Tunnel allows determination of real gas aerodynamic effects at constant M∞ and Re∞

• Evaluating use of CO2 as a test gas to support planetary missions

steves

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steves

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this tunnel was closed a few years ago. S.P. Schneider, 2015

steves

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Testing Techniques

Schlieren forflowfield

visualization

Schlieren forflowfield

visualization

Strain-gauge balances to

obtain aerodynamics

Strain-gauge balances to

obtain aerodynamics

Phosphorthermographyto obtain heat

transfer

Phosphorthermographyto obtain heat

transfer

Oil-flow for surface

streamline visualization

Oil-flow for surface

streamline visualization

Thin-film gauges to

obtain heat transfer

Thin-film gauges to

obtain heat transfer

Electronically scanned pressure

(ESP) systems

Electronically scanned pressure

(ESP) systems

Phosphor Thermography

ModelFabrication

ModelFabrication

• Casting of ceramic models

• Rapid turnaround• Complex shapes

• Casting of ceramic models

• Rapid turnaround• Complex shapes

• Two-color fluorescence

• State-of-art computerized acquisition system

• Two-color fluorescence

• State-of-art computerized acquisition system

Aeroheating data to customersVehicle Concept

Analysis ofMeasurementsAnalysis of

MeasurementsWind Tunnel

TestingWind Tunnel

Testing

• Nonlinear theory to infer accurate temperatures

• User-friendly image program (IHEAT)

• Nonlinear theory to infer accurate temperatures

• User-friendly image program (IHEAT)

ModelFabrication

ModelFabrication

Wind Tunnel Testing

Wind Tunnel Testing

Analysis ofMeasurements

Analysis ofMeasurements

Thermographic Phosphor System

Data Reduction and Analysis With IHEAT

IHEAT Main Routine

Input image data

Vehicle Design Loop

Analysis

EXTRAP

DISPER

MAP3D

Calibrations

TRANSCAL TEMPCALSYSCAL

LUTCALC

Thin-Film/Phosphor Hemisphere Comparison

Thin-film model

Phosphor data

1.12

0.64

0.56

0.28

0

h/hFR

M∞ = 10, Re∞ = 1.0 x106/ft.

Angle (degrees)

h/h F

R

0 20 40 60 800

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

Thin-film dataCFD (LATCH)Phosphor data

h/h

FR

Before and After Phosphor Thermography

BeforeDiscrete gauges150 points/run

After Global data150,000 points/run

50 weeks to obtaindata on study

5 weeks to obtaindata on study

Time savings: 10x

Fabrication cost:150K (1 model)

Fabrication cost:15K (5 models)

Cost reduction: 10x

Better Faster Cheaper

Impact to a study Increased amount of information: 1000x

Computational Aerothermodynamic Creditability

Foundation

Predictions

Calibration/validation

Comparison to:Ground-based dataPrevious flight data

Passed

Failed

Apply toflight

Hypersonicaerodynamic/aeroheating

data

100

Perc

ent

0

Ground-based experiments

Tried and proven

CFD (for full configuration)

1950 1960 1970 1980 1990 2000 2010Year

Flowchemistry

Dissociationrecombination

IonizationRadiation

Flow physicsTransitional/turbulent

Separation – reattachmentShock-shock interactions

Numerical processNon-reacting, attached, steady, laminar flow

Rem

ove

AB Productivity (Typical) – 80 Work DaysExperimental Aerodynamics

Designmodel

Pitch-pause(8 to 10 alpha/run)

Fabricate/instrument metal model Test-tunnel 1≈70 runs

Setu

p

Rem

ove

Setu

p

≈1,120cases

Test-tunnel 2≈70 runs

Constructceramic models

(in-house)

Test – tunnels1 and 2

≈200 cases

Experimental aeroheating

Computational Fluid Dynamics

Test – tunnel 3≈75 runs ≈275 plus

cases

Generatesurface

grid

Generatestructured

volume grid

Runfirstcase

Runtwo

cases≈23

casesRun≈20

cases

0 10 20 30 40 50 60 70 80Work days (8 hours/day

Tip-to tail NS solutions

Rem

ove

Setu

p

Setu

p

Phosphor thermography(one alpha/run)

rs

Phosphor mappingPhosphor mapping

Com

puta

tiona

lFl

uids

Expe

rimen

tal

Test

ing

Prog

ram

C

ontr

ibut

ions

Flowfield predictionFlowfield prediction

• Identification of vehicle instability in free-molecular region• Proposed increased spin rate solution

• Identification of subsonic dynamic instability• Proposed addition of stabilizing drogue chute

• Formed aerodynamic database• Supported design of TPS design

• Identification of vehicle instability in free-molecular region• Proposed increased spin rate solution

• Identification of subsonic dynamic instability• Proposed addition of stabilizing drogue chute

• Formed aerodynamic database• Supported design of TPS design

• Subsonic static and dynamic (spin tunnel) aerodynamic tests• Data part of aerodynamic database

• Thermographic phosphor tests for afterbody heating

• Subsonic static and dynamic (spin tunnel) aerodynamic tests• Data part of aerodynamic database

• Thermographic phosphor tests for afterbody heating

• Free-molecular and rarefied (DSMC) aero and heating calculations

• Hypervelocity aero and heating CFD computations• Transonic aero computations• Provided computations to establish transition criteria


• Hypervelocity aero and heating CFD computations• Transonic aero computations• Provided computations to establish transition criteria

Stardust Comet (Wild-2) Sample Return

rs

Genesis AerothermodynamicsC

ompu

tatio

nal

Flui

dsEx

perim

enta

lH

eatin

gPr

ogra

m

Con

trib

utio

ns • Computations provided reacting flow capability to industry engineering design code

• Backshell computations validated engineering design code predictions

• Provided transition criteria for presence of forebody cavities

• Computations provided reacting flow capability to industry engineering design code

• Backshell computations validated engineering design code predictions

• Provided transition criteria for presence of forebody cavities

• Models of four different scales fabricated with 6 different forebody cavity configurations

• Characterized transition onset with cavity size and axial location for a range of Reynolds numbers

• Heating levels varied with cavity size and were >3x stagnation• Developed method to predict heating “footprint” behind cavity

• Models of four different scales fabricated with 6 different forebody cavity configurations

• Characterized transition onset with cavity size and axial location for a range of Reynolds numbers

• Heating levels varied with cavity size and were >3x stagnation• Developed method to predict heating “footprint” behind cavity

• LAURA Navier-Stokes computations on forebody • Chemical and thermal nonequilibrium

• Forebody cavities modeled as axisymmetric grooves and obtained LAURA laminar and turbulent solutions

• Examined heating in vicinity of edge of cavity• Backshell aeroheating predicted

• LAURA Navier-Stokes computations on forebody • Chemical and thermal nonequilibrium

• Forebody cavities modeled as axisymmetric grooves and obtained LAURA laminar and turbulent solutions

• Examined heating in vicinity of edge of cavity• Backshell aeroheating predicted

Laminar

Turbulent

Cavity HeatingCavity Heating

Transition CriteriaTransition Criteria


rs

Mars Microprobe Penetrator


Com

puta

tiona

lFl

uids

Expe

rimen

tal

Hea

ting

Prog

ram

C

ontr

ibut

ions

Flowfield predictionFlowfield prediction

• Proposed novel aeroshell shape for unique mission requirements

• Defined entry heating environment for TPS design• Compiled aerodynamic database

• Proposed novel aeroshell shape for unique mission requirements

• Defined entry heating environment for TPS design• Compiled aerodynamic database

• Phosphor thermography data used in unique coupling with flight dynamic simulation to predict integrated heating loads with vehicle oscillations

• Phosphor thermography data used in unique coupling with flight dynamic simulation to predict integrated heating loads with vehicle oscillations


• Hypervelocity aero and heating CFD computations• Transonic aero computations


• Hypervelocity aero and heating CFD computations• Transonic aero computations

Computational – Experimental SynergismX-33 Boundary Layer Transition Methodology

Nov. 28, 2001 [email protected]

Roughness Dominated Transition on Reentry Vehicles

Recent Experiments Conducted at LaRC

By:

Scott A. Berry

Aerothermodynamics Branch

NASA Langley Research Center


LaRC Roughness Experiments

• 96-98: Shuttle asymmetric BLT flight anomalies

• 97-00: X-33 investigation of discrete (CL and AL)

and distributed (bowed-panels) BLT

• 98-01: X-38 BLT assessment

• 01-??: 5-deg Cones roughness database


Experimental Approach

• 20-Inch Mach 6 Tunnel

(conventional)

• Phosphor thermography

• Discrete tripping elements

(mostly)

• Large database on various

shapes, trips

Settling chamber 20 x 20 inch

test section

Schlieren windows

Flow

Model injection/retraction

system

Arc sector

Variable second

minimum

To atmosphere

Nominal Mach number: 6.0

Reynolds number (x 106/ft): 0.5 to 10.5

Dynamic pressure (psf): 69 to 1264

Total pressure (psia): 30 to 550 Total temperature (°R): 810 to 1018 Run time (minutes): 1 to 15

Flow

L = 0.050 in.L = 0.050 in.

Height = k

k = 0.0025, 0.0050, 0.0075, 0.0100 in.


Shuttle Centerline at α = 40-deg

0

50

100

150

200

250

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

INCIPIENT C = 21EFFECTIVE C = 30

Re

θ/Me

k/δ

G1

ECL1

DE1G2

ECL2G3

D1DE2

DE3ECL3

B2D2

DE4D3

D4

LAMINAR

TURBULENT

Reθ/Me ≈ C(k/δ)-1

Boundary layer edge properties calculated with BLIMP

AIAA Paper 97-0273 or JSR Vol. 35 No. 3 pp. 241-248

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Re=1.57x106/ft

Re=1.87x106/ft

Re=2.25x106/ft

Re=3.17x106/ft

Re=4.33x106/ft

Re=4.45x106/fth/h

ref

x/L

(x/L)trip

=0.375

G2 Reeff≈ 2.4x10 6/ft

Reinc

≈ 1.6x10 6/ft


X-33 Centerline

0

50

100

150

200

250

300

350

0 0.2 0.4 0.6 0.8 1 1.2

Reθ/

Me

k/δ

LAMINAR

TURBULENT

Reθ/Me ≈ C(k/ δ)-1.0

Incipient C = 45

Effective C = 60

α = 20°, 30°, and 40°

Trip �Station�

Boundary layer edge propertiesCalculated with LATCH

Trip �Station�

α = 40-deg

α = 20-deg

AIAA Paper 99-3560 or JSR Vol. 38 No. 5 pp. 646-657


X-33 Attachment Linesa = 20°

a = 30°

a = 40°

0

50

100

150

200

250

300

350

0 0.2 0.4 0.6 0.8 1 1.2

Re q/M

e

k/d

LAMINAR

TURBULENT

No Trip Effect (Laminar)

Fully Effective Trip

m

o

n

Marginal Trip Effect

New Attachment Line Data

m

o

n

mmmm

mmmm

m

oo

ooo

o

om

n

n n

n

Req/Me ª C(k/d)-1.0

Incipient C = 45Effective C = 60

Old Centerline Data

mmmm

mm

m

mm

ooo

oo

nn

nn

n

nn

a = 20, 30, 40-deg


X-33 Bowed Panels

Both 1st Row

Extended

Centerline Chine

0.005-in Discrete

0.008-in Extended

Re∞ = 3.1x106/ft

Re∞ = 4x106/ft

Side view

k = 0.002-in0.004-in0.006-in0.008-in

Configurations tested


LATCH Comparison

1

10

100

1000

0.1 1 10

Centerline Effective Transition Results Computed with LATCHR

eθ/M

e

k/δ

LAMINAR

TURBULENT

Preliminary

70 ± 20%

Shuttle α = 40-degX-33 α = 20-degX-33 α = 30-degX-33 α = 40-degX-38 α = 40-deg


Quiet Tunnel Cones

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0 5 10 15 20

GASP-LamR3 No TripR70 Single DiamondR118 Single SphereR141 Dist. Spheres

h/href

x, inches

Model 93-10 , rn=0.0001-in, α = 0.0 deg

k = 0.0115-in.

x = 2-in.

Re� = 4.4x10

6/ft


Concluding Remarks

• Roughness effects in conventional hypersonic facility

shown to be well behaved:

-must use consistent approach (i.e. same

computational method)

-results consistent across platforms

-CL and AL follow same trends

-discrete element worst case

• Noise effects needs further investigation by comparing

current database to quiet tunnel and flight results

scott a. berry [email protected] note that this is...

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