Laminar-to-Turbulent Transition in

Hypersonic BL with Spanwise

Inhomogeneity

Roger Kimmel

Principal Engineer

Aerospace Systems Directorate

Air Force Research Laboratory

16 July 2015

Distribution A: Approved for public release, distribution is unlimited. 24 June 2015, 88ABW-2015-3223

2

Overview

• Introduction

– Focus on BLT with significant spanwise nonuniformity

– Examine limits of applicability for PSE

• HIFiRE-5

– IR and Kulite measurements in Purdue

• Cone at AoA

– Stability calculations

– Re-examination of Stetson high-Reynolds Mach 6 data

• HIFiRE-1, 5a analysis

• Test capability development

– Ludwieg tube

– FLDI

– Krypton PLIF

16 October 2015

3

Push to Complex Configurations

16 October 2015

HIFiRE-5

Li 2012

Kimmel 1995

DARPA / AF Falcon HTV-2

Advanced Hypersonic

Weapon

4

Flows With Strong Spanwise

Nonuniformity

16 October 2015

HIFiRE-5 Gosse

(2009) Elliptic Cone

Huntley (2000)

HIFiRE-5

Paredes (2014)

What are limits of applicability

for PSE in complex flows?

When do non-modal

instabilities become

important?

5

Approach / Benefits

• Generate flowfields with spanwise nonuniformity

• Measure stability characteristics and compare to

PSE, search for regions where PSE may be

inadequate

• Benefits – increased confidence with PSE, improved

vehicle design

16 October 2015

Borg – HIFiRE-5

Crossflow

development

Jewell – Cone at AoA

Instability growth with

varying spanwise

nonuniformity

Tufts – PSE

Modal instabilities

in 3D flows

6

Last Year’s Results

• HIFiRE-5

– Measured fluctuating surface pressures in TAMU ACE wind tunnel

– Mach 6 results similar to Purdue noisy, but lower amplitude

– Strong effect of Mach number and tunnel conditions on observed instabilities

• HIFiRE-1 high AoA transition

– 2nd mode observed on cone at AoA in tunnel

– Indented transition front observed in flight, not in ground test

– Wind tunnel transition at AoA biased to lower Reynolds compared to flight, but not as much as a=0

– Nosetip steps probably not contributor to this

• Additional results (not briefed)

– Leading-edge trip on HIFiRE-5 flight correlated with Redk

– Refined AoA & heating for HIFiRE-5 flight

7

HIFiRE-5 IR Transition Measurements

16 October 2015

Quiet, Re=12.3x106/m

Borg (AFRL), Purdue M=6 Quiet Tunnel

Steel forebody,

PEEK frustum

IR successful, Kulites do not significantly influence results

Flow

Instrumented Blank

8

Stationary Cross Flow Instability Growth

16 October 2015 Quantitative stationary crossflow measurement may be possible

Borg (AFRL), Purdue M=6 Quiet Tunnel

x=305.1 mm

9

Traveling Cross Flow Instability Growth

16 October 2015

Re=6.6x106/m Re=8.9x106/m

Re=9.9x106/m Re=12.8x106/m

Spatial growth observable

Borg (AFRL), Purdue M=6 Quiet Tunnel

10

Comparison With PSE

16 October 2015

Re=8.3x106/m

Re=8.9x106/m

LST/LPSE agree well with data at lower Reynolds

Lakebrink (Boeing), Borg (AFRL)

11

PSE Analysis - 8-deg M=6 Blunt Cone

Experiment

16 October 2015

Jewell (AFRL, NRC)

Small radius - high N-factors, ~7

Drop in N-factor when transition occurs within swallowing region

(similar to Marineaux)

1983 AF High-Reynolds M=6 tests

Effect of entropy-swallowing on transition

12

M=6 High-Reynolds Amplication Rates

16 October 2015

Jewell (AFRL, NRC)

- Second-mode freqs push PCB capabilities

- FLDI in works

2% bluntness

Re=20x106/ft

13

HIFiRE-1 SBLI

16 October 2015

Prabhu (NASA), Kimmel (AFRL)

Wind tunnel results useful for

calibrating turbulence models for

flight SBLI

14

HIFiRE-5 Heat Transfer Analysis

16 October 2015

f=0 f=90

t=20 sec t=32 sec

Miller, Kimmel (AFRL), Jewell (AFRL,

NRC)

Transverse

conduction

explains heating

discrepancies

15

HIFiRE-5 Pressure Measurements for

Flight Attitude

16 October 2015 Surface pressures suitable for attitude determination

Miller, Kimmel (AFRL), Jewell (AFRL, NRC)

AoA (deg)

Yaw

(d

eg

)

Ao

A (

de

g)

Ya

w (

de

g)

Min

% R

MS

Devia

tio

n

Time, sec

16

Summary

• HIFiRE-5 stability

– New IR transition measurement capability

– Traveling cross flow coexists with stationary

– Traveling detectable before stationary

– Before breakdown, phase speed and wave angle predicted

well with LPSE

• Cone at AoA / bluntness analysis

– Correlating N-factor drops when Retr drops

• HIFiRE flight analysis

– Tunnel - calibrated Reynolds stress model works well for

flight SBLI

– HIFiRE-5 pressure instrumentation as FADS works well

16 October 2015

17

Upcoming Work

16 October 2015

• IR calibration and stationary/traveling crossflow analysis (Borg) –

further insight into crossflow development

• Cone stability at AoA and bluntness effects (Jewell) – effect of strong

spanwise nonuniformity on instability development

• FLDI (Jewell, Lam) – measure freestream and boundary layer

instabilities

• Freestream disturbance / shock interaction (Duan, UMR) –

receptivity, tunnel characterization

• Ludwieg Tube characterization

• Pate correlation (Juliano) –wind tunnel noise scaling

• LASTRAC/PSE3D analysis for 3D flows (Tufts) – provide LPSE

analysis for HIFiRE-5 and cone at AoA

• Krypton LIF (Narayanaswamy, Lam, Carter) – boundary layer imaging

• HIFiRE-5b – refly scheduled November 2015

18

Upcoming Work

16 October 2015

Andor iXON

EMCCD

Camera

AutoTracker III with

Prism Harmonic

Separator

Lumonics HD-

300

Dye Laser

GCR-170 Nd:YAGSpherical convex lens

Laser Sheet, = 214.7 nm

=355 nm

= 532 nm

= 544 nm

AT-III

Cylindrical concave lens

Narayanaswamy,

Lam, Carter – Kr

LIF

Ludwieg Tube - commissioning

Jewell – Cone at AoA

Jewell, Lam - FLDI

High-Reynolds M=6 tunnel,

Ludwieg tube

Medtherm

PCB

Bench setup

Shock tube checkout

High-Reynolds Mach 6,

Ludwieg tube

Correlation measurements

Bench demo in jet

Ludwieg tube demo

19

Technical Challenges

• Amplitude-based transition prediction

– Atmospheric disturbance measurement

– Surface quality prediction

– Wind tunnel disturbance measurement

• Bluntness transition mechanisms

– Implications for transition control (If you mediate one transition mechanism, what pops up next to replace it?)

– Implications for transition prediction (Do we clearly know where our methods are applicable and inapplicable?)

16 October 2015

20

Acknowledgments

• Steve Schneider, Purdue

• Cam Carter, James Miller, Ben Hagen, AFRL

16 October 2015

21

BACKUP

16 October 2015

22

Publications

16 October 2015

Borg, M. P., Kimmel, R. L., Hofferth, J., Bowersox, R. D. W. and Mai, C. L. N., “Freestream Effects on Boundary

Layer Disturbances for HIFiRE-5,” AIAA 2015-0278, January 2015.

Kimmel, R. L., Prabhu, D., “HIFiRE-1 Turbulent Shock Boundary Layer Interaction –Flight Data and

Computations,” AIAA paper 2015-xxxx, June 2015.

Jewell, J. S., Miller, J. H., Kimmel, R. L., “Correlation of HIFiRE-5 Flight Data With Computed Pressure and Heat

Transfer,” AIAA paper 2015-xxxx, June 2015.

Kimmel, R.L., Adamczak, D., Paull, A., Paull, R., Shannon, J., Pietsch, R., Frost, M., and Alesi, H., “HIFiRE-1

Ascent Phase Boundary Layer Transition,” AIAA Journal of Spacecraft and Rockets, vol. 52, no. 1, January-February

2015.

Stanfield, S. A., Kimmel, R. L., Adamczak, D., and Juliano, T. J., “Boundary-Layer Transition Experiment During

Reentry of HIFiRE-1,” AIAA Journal of Spacecraft and Rockets, vol. 52, no. 3, May-June 2015, pp. 637-649.

Juliano, T. J., Adamczak, D. A., and Kimmel, R. L., “HIFiRE-5 Flight Test Results,” AIAA Journal of Spacecraft

and Rockets, vol. 52, no. 3, May-June 2015, pp. 650-663.

Borg, M. P., Kimmel, R. L., and Stanfield, S., “Traveling Crossflow Instability for the HIFiRE-5 Elliptic Cone,”

AIAA Journal of Spacecraft and Rockets, vol. 52, no. 3, May-June 2015, pp 664-673.

23

Business Update

16 October 2015

• Budget (7/13/2015)

• Total authority - $375,000

• Obligated - $286,423

• Unobligated - $88,577

• Full-time personnel

• Dr. Matthew Borg – AFRL/RQHF

• Dr. Joseph Jewell – NRC postdoc

• Dr. Brian Lam – Spectral Energies

• Dr. Matthew Tufts – OAI postdoc

• Summer personnel

• Dr. Thomas Juliano – Notre Dame (SFFP)

• Christopher Huffman – Notre Dame (SFFP)

• Dr. Lian Duan – University Missouri-Rolla

• Dr. Venkateswaran Narayanaswamy – NC State

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FLDI Cross-Correlation Measurements

16 October 2015

Jewell (AFRL, NRC), Lam (AFRL, Spectral Energies), Parziale (Stevens)

FLDI phase velocity measurements feasible