Experimental and Numerical Investigation of Air … · Experimental and Numerical Investigation of Air Radiation in Superorbital ... to Shimadzu HPV-1 1MHzhigh speed camera ... Shimadzu

Experimental and Numerical Investigation of AirRadiation in Superorbital Expanding Flow

Han Wei 1 Richard G. Morgan 1 Timothy J. McIntyre1

Aaron M. Brandis 2 Christopher O. Johnston 3

1Centre for Hypersonics, the University of Queensland

2AMA at NASA Ames Research Center

3NASA Langley Research Center

9th June 2017

https://ntrs.nasa.gov/search.jsp?R=20170009879 2018-07-06T17:22:08+00:00Z

Outline

1 Introduction

2 Experimental Campaign

3 Numerical Simulation

4 Results and AnalysisFlow EstablishmentVUV Spectra

5 Conclusions

Han Wei Centre for Hypersonics 1 / 44

Outline

1 Introduction




5 Conclusions


Afterbody TPS

Afterbody Heatshield:

Cocooning the bulk of the vehicle surface

Bearing large design uncertainty up to 300%[1]

Afterbody Radiative Heating:

May be important for Superorbital re-entry: Mars return

Found to be significant with state-of-the-art simulations[2]

No discernible data recorded by afterbody radiometers ofFire II and Apollo 4

[1] Michael J. Wright, Frank S. Milos, and Phillippe Tran. “Afterbody Aero-heating Flight Data for Planetary Probe Thermal Protection System Design”.In: Journal of Spacecraft and Rockets 43.5 (Sept. 2006), pp. 929–943.

[2] Christopher O. Johnston and Aaron M. Brandis. “Features of AfterbodyRadiative Heating for Earth Entry”. In: Journal of Spacecraft and Rockets52.1 (2015), pp. 105–119.


Post-mission Analyses

Wright et al.[3] achieved excellent agreement with Fire IIforebody convective heating data, but the afterbodyexperimental data were a factor of two higher than thenoncatalytic predictions

Johnston and Brandis[4] re-examined the FIRE IIafterbody measurements and questioned the analysis of theradiometer data. Major sources of model uncertainties forafterbody radiation were identified: the rate coefficient forthe three-body electron-ion recombination reaction, theescape factors on collisional-radiative modelling, and theimpact of forebody ablation.

[3] Michael Wright, Mark Loomis, and Periklis Papadopoulos. “AerothermalAnalysis of the Project Fire II Afterbody Flow”. In: Journal of Thermo-physics and Heat Transfer 17.2 (2003), pp. 240–249.[4] Christopher O. Johnston and Aaron M. Brandis. “Features of AfterbodyRadiative Heating for Earth Entry”. In: Journal of Spacecraft and Rockets52.1 (2015), pp. 105–119.


Recent Advancements in Numerical Models

Johnston and Panesi[5]: treating nitrogen atoms of differentgrouped electronic levels as individual species in the flowfield model, coupling radiative transition rates to thespecies continuity equations, adopting a ray-tracingapproach in radiation transport calculation and developinga nonequilibrium model for NO

Lopez et al.[6] improved the non-Boltzmann modelling ofnitrogen by adopting a state-to-state description ofgrouped electronic states

[5] Christopher O. Johnston and Marco Panesi. “Advancements in After-body Radiative Heating Simulations for Earth Entry”. In: 46th AIAAThermophysics Conference. AIAA Aviation. American Institute of Aero-nautics and Astronautics, June 13, 2016.[6] Bruno Lopez, Christopher O. Johnston, and Marco Panesi. “ImprovedNon-Boltzmann Modeling for Nitrogen Atoms”. In: 46th AIAA Thermo-physics Conference. AIAA Aviation. American Institute of Aeronautics andAstronautics, June 10, 2016.


Recent Advancements in Numerical Models

West et al.[7] performed sensitivity analysis and uncertaintyquantification of afterbody radiation for Stardust at peakafterbody radiative heating conditions. Four variables werefound to contribute to nearly 95% of the uncertainty: theelectronic-impact excitation rate for N between levels 2 and5 and the rates of three chemical reactions that affect thenumber densities of N, N+, O and O+.

Validation data of afterbody radiation is in high demand,particularly in the VUV wavelength range

[7] Thomas K. West IV, Christopher O. Johnston, and Serhat Hosder.“Uncertainty and Sensitivity Analysis of Afterbody Radiative Heating Pre-dictions for Earth Entry”. In: 54th AIAA Aerospace Sciences Meeting.AIAA SciTech. American Institute of Aeronautics and Astronautics, Jan. 2,2016.


Outline

1 Introduction




5 Conclusions


Facility, Model and Flow Conditions

X2 Expansion Tunnel

Acceleration TubeReservoir Compression Tube Schock Tube Test SectionNozzle

Primary Diaphragm Secondary Diaphragm

SD 1 2 3 ST 1 2 3 AT 1 2 3 4 5 6

Acceleration TubeReservoir Compression Tube Schock Tube Test SectionNozzle

Primary Diaphragm Secondary Diaphragm

Test Model:

54◦ wedge: 25mm tall and 100 mm wide

Flow Conditions:

ConditionVelocity(m/s)

StaticPressure (Pa)

StaticTemperature (K)

StagnationEnthalpy (MJ/kg)

1 9714±0.6% 1308±8.8% 2609±1.1% 50.7±0.9%2 10899±0.3% 1523±6.8% 2713±1.0% 63.4±0.7%3 11837±1.0% 843±10% 2892±0.8% 75.4±2.0%


The Spectral Measurements

21.5

3.2

5 5.7

5

8.2

5

MgF2 window

VUV Measurement

across Model Width

VUV Measurement

through Model Surface

21

Attached

Shock Wave

54

25


Aross-Wedge Measurement


Through-Wedge Measurement


Optics Layout

Filtered high speed imaging with a bandpass filter coupledto Shimadzu HPV-1 1MHz high speed camera (left)

VUV emission spectroscopy system (right)

Flow

Andor iStar

DH340T

ICCD Camera

Flat Mirror

SlitAperture

Concave Mirror

f=500mm

Nozzle Centreline

MgF2 WindowWedge

Model

McPherson Nova 225

1m Focal Length

VUV Spectrometer

BellowsOptics Box

Pfeiffer TPG 261

Vacuum Gauge

Pfeiffer TPG 361

Vacuum Gauge

Shimadzu HPV-1 1MHz

High Speed Camera

Bandpass Filter

Nikkor Micro 200mm F/4D IF-ED

Pump Flange

Pump Flange


Outline

1 Introduction




5 Conclusions


Numerical Simulation

Flow Solver: Eilmer3[8]

Grid Generator: GridPro

Radiation Modelling: NEQAIR V14[9]

Chemical Species: 11 species air including N, N+, NO,NO+, N2, N +

2 , O, O+, O2, O +2 and e–

Thermo-chemical model: Park’s two temperature modeland associated reaction rates[10] with with rate controllingtemperature defined as Td = T 0.7

tr T 0.3ve

[8] R. J. Gollan and P. A. Jacobs. “About the formulation, verification andvalidation of the hypersonic flow solver Eilmer”. In: International Journalfor Numerical Methods in Fluids 73.1 (Sept. 2013), pp. 19–57.[9] Aaron Michael Brandis and Brett A Cruden. “NEQAIRv14. 0 ReleaseNotes: Nonequilibrium and Equilibrium Radiative Transport Spectra Pro-gram”. 2014.[10] Chul Park. “Review of chemical-kinetic problems of future NASA mis-sions. I - Earth entries”. In: Journal of Thermophysics and Heat Transfer7.3 (Sept. 1993), pp. 385–398.


Numerical Simulation

Grid topology and boundary conditions

0 10 20 30 40 50

X (mm)

0

20

10

30

40

50

Y(m

m)

Supersonic Inflow

Slip Wall

Non-Slip Wall at 298.15K

Extr

apola

ted O

utf

low

Extrapolated Outflow


Outline

1 Introduction




5 Conclusions


Outline

1 Introduction




5 Conclusions


Flow Establishment

High speed video through Thorlabs FBH780-10 bandpass filterat 0.5 MHz


Flow Establishment

Synchronisation of under-model probe pressure, trigger signalsand camera outputs

0 50 100 150 200 250 300

Time (µs)

0

5

10

15

20

25

30

Nor

mal

ised

Ou

tpu

t

Photodiode

Trigger Box

Probe Pressure

ICCD

HPV-1


Flow Steadiness

Extracted pixel counts at 3.25mm above wedge top for Shotx2s3022 with Condition 3

20 30 40 50

X (mm)

0

20

40

60

80

Cou

nts

72µs

74µs

76µs

78µs

80µs

82µs

84µs


Outline

1 Introduction




5 Conclusions


VUV Spectra

Raw spectral image for Shot x2s3022 with Condition 3

Test Flow

Edge of Optical Path

Edge of Optical Path

Shock

Layer

Expansion

Fan


Calibrated Spectra

Calibrated spectral image for Shot x2s3022 with Condition 3

120 130 140 150 160 170 180

Wavelength (nm)

0

5

10

15

Pos

t-S

hock

Dis

tan

ce(m

m) Condition-3: x2s3022

0 1 2 3 4 5

Radiance (W/(m2·sr)) ×105

0

5

10

15

Radiance of 149.3nm N line

120 130 140 150 160 170 180

Wavelength (nm)

0

1

2

3

4

5

6

7

8

9

Sp

ectr

alR

adia

nce

(W/(

m2·sr·nm

)) ×105 Spatially Averaged Spectrum

Peak Region

Expansion Fan0 3 6 9

Spectral Radiance (W/(m2·sr·nm))×105


Radiator Identification

Shock layer radiators for Shot x2s3026 with Condition 1

N

N

NN

C CH N

Al+

Fe+

N

O

O



Expansion fan radiators for Shot x2s3026 with Condition 1

NN NN C C

H

N

Al+

Fe+

O

N

Fe+

NFe+




C

N

N

N

N

C CN

Al+

Fe+

Fe+

N

H

N

OFe+

Al+

Fe+




N

N

N

C

C

N

Fe+

N

H

N

O

C/Fe+

N Fe+

C Al+Al+

Fe+

Al+

Fe+




N

N

N

N

N

C C

Al+

Fe+

C C

N

H

Fe+

C

N

Fe+

Al+

Fe+

O

Fe+

Fe+

Fe+

Al+

Fe+




N

N

N

C

C

Al+

Fe+C C

N

H

Fe+

C

NO

Fe+

Fe+

Al+

Fe+N

Fe+



The level of contamination increases with flow enthalpy

The expansion fan spectra tend to be packed with moredistinguishable features of contaminants

C and Al+ can be stronger relative to N lines in theexpansion fan for certain conditions


Through-Wedge Spectra

Through-wedge spectrum of Shot x2s3056 with Condition 1

120 130 140 150 160 170 180

Wavelength (nm)

0

5

10

15

Dis

tan

ce(m

m)

Condition-1: x2s3056

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6


0

5

10

15


120 130 140 150 160 170 180

Wavelength (nm)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Sp

ectr

alR

adia

nce

(W/(

m2·sr·nm


Region 1

Region 20.0 2.5 5.0 7.5





120 130 140 150 160 170 180

Wavelength (nm)

0

5

10

15

Dis

tan

ce(m

m)


0.0 0.5 1.0 1.5 2.0 2.5


0

5

10

15


120 130 140 150 160 170 180

Wavelength (nm)

0

1

2

3

4

5

Sp

ectr

alR

adia

nce

(W/(

m2·sr·nm


Region 1

Region 20 2 4 6





120 130 140 150 160 170 180

Wavelength (nm)

0

5

10

15

Dis

tan

ce(m

m)


0 1 2 3 4 5 6 7 8


0

5

10

15


120 130 140 150 160 170 180

Wavelength (nm)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Sp

ectr

alR

adia

nce

(W/(

m2·sr·nm


Region 1

Region 20.0 0.5 1.0 1.5



VUV Spectra vs Simulations

Radiance profiles of the 149 nm N line at 3.25, 5.75 and8.25 mm above the top of the wedge compared betweenexperiments and NEQAIR simulations for Condition 1

0 5 10 15 20

Post-Shock Distance (mm)

0

1

2

3

Rad

ian

ce(W

/(m

2·Sr)

)

×104

3.25mm-x2s3026

3.25mm-NEQAIR

5.75mm-x2s3031

5.75mm-NEQAIR

8.25mm-x2s3037

8.25mm-NEQAIR




0 5 10 15 20


0

1

2

3

4

Rad

ian

ce(W

/(m

2·Sr)

)

×104

3.25mm-x2s3026

3.25mm-NEQAIR

5.75mm-x2s3031

5.75mm-NEQAIR

8.25mm-x2s3037

8.25mm-NEQAIR



Experiment and NEQAIR results of the 149 nm N line, as wellas selected flow variables along the line of sight at 8.25 mmabove the top of the wedge for Condition 1

0 5 10 15 20


0

1

2

3

Rad

ian

ce(W

/(m

2·Sr)

)T

emp

erat

ure

(K)

×104

0

2

4

6

8

Nu

mb

erD

ensi

ty(c

m−

3)

×1017

x2s3037

NEQAIRTtr

Tve

NN

NN+×100

Ne−×100




0 5 10 15 20


0

1

2

3

Rad

ian

ce(W

/(m

2·Sr)

)T

emp

erat

ure

(K)

×104

0

2

4

6

8

Nu

mb

erD

ensi

ty(c

m−

3)

×1017

x2s3037

NEQAIRTtr

Tve

NN

NN+×100

Ne−×100



Density and selected species mass fraction distributions alongthe line of sight at 8.25 mm above the top of the wedge forCondition 1

0 5 10 15 20


0.0

0.5

1.0

1.5

2.0

2.5

Den

sity

(kg/

m3)

×10−2

0

2

4

6

8

10

Mas

sF

ract

ion

(%)

Density

ωN − 60%

ωN2

ωN+ × 10

ωe− × 105




0 5 10 15 20


0.0

0.5

1.0

1.5

2.0

Rad

ian

ce(W

/(m

2·Sr)

)

×105

3.25mm-x2s3028

3.25mm-NEQAIR

5.75mm-x2s3033

5.75mm-NEQAIR

8.25mm-x2s3042

8.25mm-NEQAIR




0 5 10 15 20


0.0

0.5

1.0

1.5

Rad

ian

ce(W

/(m

2·Sr)

)T

emp

erat

ure

(K)

×105

0

2

4

6

8

Nu

mb

erD

ensi

ty(c

m−

3)

×1017

x2s3042

NEQAIRTtr×5

Tve×5

NN

NN+×20

Ne+×20




0 5 10 15 20


0.0

0.5

1.0

1.5

2.0

2.5

Den

sity

(kg/

m3)

×10−2

0.0

0.5

1.0

1.5

2.0

2.5

Mas

sF

ract

ion

(%)

Density

ωN − 72%

ωN2

ωN+

ωe− × 104




0 5 10 15 20


0

1

2

3

4

5

Rad

ian

ce(W

/(m

2·Sr)

)

×105

3.25mm-x2s3022

3.25mm-NEQAIR

5.75mm-x2s3036

5.75mm-NEQAIR

8.25mm-x2s3044

8.25mm-NEQAIR




0 5 10 15 20


0

1

2

3

4

Rad

ian

ce(W

/(m

2·Sr)

)T

emp

erat

ure

(K)

×105

0

1

2

3

Nu

mb

erD

ensi

ty(c

m−

3)

×1017

x2s3044

NEQAIRTtr×10

Tve×10

NN

NN+×10

Ne+×10




0 5 10 15 20


0.0

0.2

0.4

0.6

0.8

1.0

Den

sity

(kg/

m3)

×10−2

0

2

4

6

8

Mas

sF

ract

ion

(%)

Density

ωN − 65%

ωN2 × 10

ωN+

ωe− × 104


Filtered Images vs Simulations

Radiance profiles of the 777 nm oxygen triplet at 3.25, 5.75 and8.25 mm above the top of the wedge compared betweenexperiments and NEQAIR simulations for Condition 2

0 5 10 15 20


0

2

4

6

Rad

ian

ce(W

/(m

2·Sr)

)

×104

3.25mm-x2s3042

3.25mm-NEQAIR

5.75mm-x2s3042

5.75mm-NEQAIR

8.25mm-x2s3042

8.25mm-NEQAIR




0 5 10 15 20


0.0

0.5

1.0

1.5

2.0

2.5

Den

sity

(kg/

m3)

×10−2

0

1

2

3

4

Mas

sF

ract

ion

(%)

Density

ωO − 20%

ωO2

ωO+

ωe− × 104



Radiance profiles of the 777 nm oxygen triplet at 3.25, 5.75 and8.25 mm above the top of the wedge compared betweenexperiments and NEQAIR simulations for Condition 3

0 5 10 15 20


0.0

0.5

1.0

1.5

Rad

ian

ce(W

/(m

2·Sr)

)

×105

3.25mm-x2s3044

3.25mm-NEQAIR

5.75mm-x2s3044

5.75mm-NEQAIR

8.25mm-x2s3044

8.25mm-NEQAIR




0 5 10 15 20


0.0

0.2

0.4

0.6

0.8

1.0

Den

sity

(kg/

m3)

×10−2

0

1

2

3

4

Mas

sF

ract

ion

(%)

Density

ωO − 20%

ωO2

ωO+

ωe− × 104


Outline

1 Introduction




5 Conclusions


Conclusions

The spatial profiles of 149 and 174nm N radiance are ingeneral of larger spans than those predicted by NEQAIR

For Conditions 2 and 3, the peak radiance levels aresignificantly underestimated. Large departures of predictedradiance values from experiment appear to occur at thestart of the expansion fan where the electron-ionrecombination process commences

NEQAIR results agree well with the filtered images of777nm oxygen triplet in the compression region and at thestart of the expansion fan for Condition 2. For Condition3, radiance in the compression region and at the start ofthe expansion fan are underpredicted by as much as 40%,but the afterbody radiance is overpredicted by up to 100%


Many Thanks


Any Questions?

Figure: Long exposure image of CO2 flow over the wedge


Documents

Experimental and Numerical Investigation of Air … · Experimental and Numerical Investigation of Air Radiation in Superorbital ... to Shimadzu HPV-1 1MHzhigh speed camera ... Shimadzu