Hypersonic Aerothermochemistry Research

Hypersonic Materials Challenges

Rodney Bowersox

Texas A&M University, College Station, TX

May, 2016College Station, Texas

•  Outline–  Introduction

–  Laboratory

–  Challenges

•  Acknowledgment–  Sponsors: AFOSR, AFRL, NASA,

NSF, ONR and Private Industry

Introduction - Hypersonic Material Challenges -

•  Ablation–  Excessive thermal loading

•  Viscous effects•  Shock boundary layer interactions

•  …

LarsonandNachtsheim,NASA1970.

Cross-hatched roughness

Transitional Turbulent

Fine-scale roughness

Laminar

Introduction - Hypersonic Scientific Challenges -

•  Hypersonic viscous flows include:–  Mechanical non-

equilibrium

–  Thermal non-equilibrium

–  Chemical non-equilibrium

–  Fluid-surface coupling

•  Beyond full physics based model free simulations

(ρv)L

Solid Surface

Liquid Layer

Hot Gaseous Turbulent Boundary Layer

(ρv)wGas Interface

Solid-Liquid Interface

y

x

Velocity Boundary Layer Thickness

Thermal Boundary Layer Thickness

ue, Te, Y (n)e

u = ue T = Te

T = Tmelt

qS

0

Surface Roughness

qw

!"#$%$&'($$!"#$%$&')$

M = 5

National Aerothermochemistry Laboratory

•  Team: R. Bowersox, D. Donzis, S. North, H. Reed, W. Saric, E. White •  Established: 2004 by R. Bowersox •  Sponsors: AFOSR, AFRL, NASA, NSF, ONR and Industry

Hypersonic Boundary Layer Stability and Transition

Hypersonic Turbulent Flows

Thermal & Chemical Non-equilibrium

Diagnostic Development

Vacuum Ejector

High Pressure Air Supply

0.5MW Heater

ACE Tunnel

SHR Tunnel

VE

NO

M

PULSED HYPERSONIC TUNNELS

M6QT

Ven

t Hoo

d

Loft with student offices

Bldg 1271

Bldg 1268 Bldg 1268a

VE

NO

M

Lam

inar

Fl

ame

Fac.

CONTROL ROOM H

YP

ER

VE

LO

CIT

Y

RE

SEA

RC

H T

UN

NE

L

LAB 1

LAB 2

INSTRUMENTATION AND MODEL ASSEMBLY

Faci

litie

s

BLOW-DOWN TUNNELS

Hypervelocity Flows

NAL - Facilities

FacilityName Mach# TestSec2on UnitRe[106/m]RunTime/DutyCycle

NASALangleyMach6QuietTunnel(M6QT)5.9 18.5cmdia 3–11(quiet)

40sec/2.5hrs

AcJvely-ControlledExpansion(ACE)Tunnel5–8

22.9cm×35.6cm

1–740sec/2.5hrs

HypervelocityResearchTunnel(HXT)5-15 92.0cmdia 0.1-100

0.4–10ms/3hrs

SupersonicHigh-ReynoldsTunnel(SHR) 2.2,3.0,or5.0

7.6cm×7.6cm

Upto5030min/2.5hrs

RepeJJvelyPulsedHypersonicTestCells3-6

2.8cm,5.1cm10.2cmx10.2cm

0.06–3.02–200ms

@0.03–1.0Hz

Mach 6 QT

ACE tunnel VENOM2 Pulsed Tunnels SHR HXT

YAG$1$

YAG$2$

DYE$2$

SFM$2$

SFM$1$

Probe$laser$system$1$

Probe$laser$system$2$

Photodissocia;on$laser$1$

Pulse/delay$1$

DYE$1$

YAG$3$

YAG$4$

DYE$4$

SFM$4$

SFM$3$

Probe$laser$system$2$

Probe$laser$system$4$

Photodissocia;on$laser$2$

Pulse/delay$2$DYE$3$

•  Advanced diagnostics are used to quantify flow properties ranging from non equilibrium molecular effects to fundamental hydrodynamics

–  Laser/Optical based diagnostics •  Particle Image Velocimetry (PIV) •  Vibrationally-excited NO Monitoring (VENOM)

–  Molecular Tagging Velocimetry (MTV)

–  Planar Laser-Induced Fluorescence (PLIF)

–  Dual Plane

•  Coherent Anti-Stokes Raman Spectroscopy (CARS)

•  Raman and Emission Spectroscopy

•  Pressure/Temperature sensitive paint (PSP)

•  Focusing schlieren w/ deflectometry

•  Infrared thermography

–  Conventional Diagnostics

–  Multiple-overheat hot-wire anemometry (HWA)

–  Kulite and PCB Pressure Transducers

NAL - Instrumentation

Hypersonic Transition Studies Roadmap

2nd Mode

Experimental Accomplishments •  Flared cone in M6QT •  2nd Mode, adiabatic– Saric •  Cold wall breakdown in

M6QT – Saric and Bowersox

Cross-flow

Experimental Accomplishments •  Axisymmetric Cone at AoA in M6QT • 3D cross-flow

measurements– Saric •  HiFIRE-5 Elliptic Cone • Traveling mode in ACE –

Kimmel, Borg, Bowersox •  Environmental disturbance

effects in ACE and M6QT – Bowersox and Reed

Bypass

Experimental Accomplishments •  Flat Plate Trip growth rates and transition in ACE - Bowersox

•  Cone nose-tip roughness growth Rates in M6QT – White

•  Blunt body transient growth in ACE – Reshotko and Bowersox

Real Gas Effects

NEXT STEPS

0

5

10

15

20

25

30

1 10 100 1000 10000

u eff+

y+

Semper, M = 5.7, Re = 3600

Peltier, M = 4.9, Re = 40000

Tichenor, M = 4.9, Re = 40000

HIFIRE&5&in&ACE&at&M&=&6&

Base of flare 4” aft of exit plane

Hofferth et al AIAA Paper 2010; Borg et al AIAA Paper 2015; Semper and Bowersox AIAA J. 2016 (in review); Leidy et al AIAA Paper 2016.

Turbulence Studies Roadmap

Equilibrium

Modeling Accomplishments • Second order transport equations derived • Algebraic heat flux model

• Validated over M = 0.02-12.0 • Established near wall scaling

for the turbulent Prandtl No.

Experimental Accomplishments • Quantified and characterized underlying flow structure for a high Re Mach 3 & 5 BL in SHR

• Characterized High Mach, Low-Re effects • Quantified Low Re Tripped

flow in ACE (NASA Pizza Box) • Quantified instability growth

Mechanical Non-Equilibrium

Modeling Accomplishments • Second order transport equations derived • Algebraic model with MNE • Pressure gradient effect on

Reynolds analogy explained • Demonstrated applicability of second order modeling for FPG

• Demonstrate for APG

Experimental Accomplishments • FPG/roughness effects (M=3,5) • Shock-turbulence interaction • APG effects at M = 5 • Shock BL Interaction (ONR) • Turbulent heat flux (VENOM)

Thermal Non-Equilibrium

Modeling Accomplishments • Second order transport equations derived • Algebraic model with TNE

developed • Investigate molecular

exchange mechanisms (AFOSR)

Experimental Accomplishments • Quantified subcritical channel flow with vibrational TNE • Demonstrated increased rate

of relaminarization w/ plasma • TNE àMNE

• Mach 7 Plasma TNE (AFOSR) • True Enthalpy Non-Equilibrium • High temperature Bls to

validate modeling • Include MNE effects

Chemical Non-Equilibrium

Modeling Accomplishments • Second order transport equations derived

• Low order heat flux model with CNE • Generalize modeling

framework

Experimental Accomplishments • Supersonic Combustion Flows • Demonstrate VENOM/

VENOM2 in combusting flow • Validate Modeling

0.0

0.4

0.8

1.2

1.6

0.0 4.0 8.0 12.0

y/d

Mach No.

Watson (1978) Present Theory

dp/dx%<%0%!%decrease%in%Reynolds%stress%

M∞%=%5%

!"#$%$&'($$!"#$%$&')$

M = 5

M = 6

Re/m = 2 x 106

Bowersox, JFM 2009; Tichenor et al JFM 2013; Peltier et al Phys. Fluids, 2014; Mai et al, AIAA Paper 2014; Fuller et al JFM 2014.

•  Hypersonic Thermal and Mechanical Loading –  Stability and Transition

•  3D Crossflow on HIFIRE-5 2:1 Elliptic Cone •  2nd Mode on cooled cone in M6QT •  Transient Growth on Orion Capsule

–  Turbulent Flow •  Reynolds shear stress and turbulent heat flux modeling •  Thermal nonequilibrium •  Mechanical nonequilibrium

•  Diagnostic Development –  Laser based thermometry and

velocimetry

•  Facility Development –  High Enthalpy Hypervelocity Tunnel

Current NAL Projects

•  Simulation is beyond a full physics based approach •  Dearth of empirical data for model development and validation

•  High enthalpy facilities with sufficient run time and accurate freestream chemistry do not exist.

Challenges

Thermal Environment (Freestream)

Chemical Environment (Surface Chemistry)

Shear Environment (Roughness Effects)