Daniel R. Millman, Ph.D., Chief Technology Officer
33
Stratolaunch LLC Approved for Public Release April 2021 Page 1 Stratolaunch LLC Approved for Public Release April 2021 Page 1 Introduction to Hypersonic Flow Daniel R. Millman, Ph.D., Chief Technology Officer April 2021
Transcript of Daniel R. Millman, Ph.D., Chief Technology Officer
Stratolaunch LLC
Approved for Public Release
April 2021Page 1
Stratolaunch LLC
Approved for Public Release
April 2021Page 1
Introduction to Hypersonic FlowDaniel R. Millman, Ph.D., Chief Technology OfficerApril 2021
Stratolaunch LLC
Approved for Public Release
April 2021Page 2
AGENDA
SECTION 1 WHAT DO WE MEAN BY “HYPERSONICS”
SECTION 2 HYPERSONIC AEROTHERMODYNAMICS
SECTION 3 IMPLICATIONS TO COMBAT SURVIVABILITY
Stratolaunch LLC
Approved for Public Release
April 2021Page 3
WHAT IS THE MACH NUMBER?
Zone of Action Zone of Silence
Mach Cone
Zone of Action
Stratolaunch LLC
Approved for Public Release
April 2021Page 4
MACH REGIMES
Stratolaunch LLC
Approved for Public Release
April 2021Page 5
SO, WHAT MAKES A FLOW HYPERSONIC?
Stratolaunch LLC
Approved for Public Release
April 2021Page 6
WHAT WE MEAN BY HYPERSONICS
Breaking the Heat Barrier!
Stratolaunch LLC
Approved for Public Release
April 2021Page 7
1959-1968 X-15
Stratolaunch LLC
Approved for Public Release
April 2021Page 8
1966-1967 PRECISION RECOVERY INCLUDING MANEUVERING ENTRY (PRIME)
Stratolaunch LLC
Approved for Public Release
April 2021Page 9
1979-1981 ADVANCED MANEUVERING REENTRY VEHICLE (AMARV)
Stratolaunch LLC
Approved for Public Release
April 2021Page 10
2010-2013 X-51A WAVE-RIDER
Stratolaunch LLC
Approved for Public Release
April 2021Page 11
2011 ADVANCED HYPERSONIC WEAPON
Stratolaunch LLC
Approved for Public Release
April 2021Page 12
AGENDA
SECTION 1 WHAT DO WE MEAN BY “HYPERSONICS”
SECTION 2 HYPERSONIC AEROTHERMODYNAMICS
SECTION 3 IMPLICATIONS TO COMBAT SURVIVABILITY
Stratolaunch LLC
Approved for Public Release
April 2021Page 13
HYPERSONIC FLOW CHARACTERISTICS
Stratolaunch LLC
Approved for Public Release
April 2021Page 14
THIN SHOCK LAYERS
Stratolaunch LLC
Approved for Public Release
April 2021Page 15
ENTROPY LAYER
Stratolaunch LLC
Approved for Public Release
April 2021Page 16
VISCOUS INTERACTION
Stratolaunch LLC
Approved for Public Release
April 2021Page 17
QUANTIFYING VISCOUS INTERACTION
Stratolaunch LLC
Approved for Public Release
April 2021Page 18
NEWTONIAN FLOW
Stratolaunch LLC
Approved for Public Release
April 2021Page 19
MODIFIED NEWTONIAN FLOW
Stratolaunch LLC
Approved for Public Release
April 2021Page 20
COMPARISON OF MODIFIED NEWTONIAN LAW WITH COMPUTATIONAL FLUID DYNAMICS
Ref: Anderson, Fundamentals of Aerodynamics, Figure 10.10. Surface-pressure distribution on an axisymmetric body of parabolic shape, M=4.
Stratolaunch LLC
Approved for Public Release
April 2021Page 21
MACH NUMBER INDEPENDENCE PRINCIPLE
Ref: Anderson, Fundamentals of Aerodynamics, Figure 14.13.Comparison between Newtonian and exact results for the pressure coefficient on a sharp wedge and a sharp cone.
Stratolaunch LLC
Approved for Public Release
April 2021Page 22
MACH NUMBER INDEPENDENCE PRINCIPLE
Ref: Anderson, Fundamentals of Aerodynamics, Figure 14.14. Drag Coefficient for a sphere and a cone cylinder from ballistic range measurements.
Stratolaunch LLC
Approved for Public Release
April 2021Page 23
HYPERSONIC FLOW OVER A FLAT PLATE
Ref: Anderson, Hypersonic and High Temperature Gas Dynamics, Fig. 3.6, Newtonian results for a flat plate as a function of angle of attack.
Stratolaunch LLC
Approved for Public Release
April 2021Page 24
DIRECTIONAL STABILITY
Stratolaunch LLC
Approved for Public Release
April 2021Page 25
X-15 VERTICAL TAIL
Stratolaunch LLC
Approved for Public Release
April 2021Page 26
1950’S HYPERSONIC CHALLENGE
Stratolaunch LLC
Approved for Public Release
April 2021Page 27
ESTIMATING HEAT FLUX
Stratolaunch LLC
Approved for Public Release
April 2021Page 28
ESTIMATING HEAT FLUX
Stratolaunch LLC
Approved for Public Release
April 2021Page 29
PETE KNIGHT’S MACH 6.7 FLIGHT IN THE X-15A-2
B-52
External fuel tanks Hypersonic research
engine model
X-15A-2
As a point of reference, the entireoutput of a moderate-size nuclearpower plant would be required toprovide this heating rate to a 1-m2
piece of material.van Wie et al
If there had been any question that theairplane was going to come back in thatshape, we never would have flown it.
Jack KolfX-15 Project Engineer
Ramjet
Stratolaunch LLC
Approved for Public Release
April 2021Page 30
HIGH TEMPERATURE EFFECTS
Stratolaunch LLC
Approved for Public Release
April 2021Page 31
AGENDA
SECTION 1 WHAT DO WE MEAN BY “HYPERSONICS”
SECTION 2 HYPERSONIC AEROTHERMODYNAMICS
SECTION 3 IMPLICATIONS TO COMBAT SURVIVABILITY
Stratolaunch LLC
Approved for Public Release
April 2021Page 32
IMPLICATIONS FOR OFFENSIVE SYSTEMS
• Physics drives the design– Glide weapons designed for minimum wave drag – Both glide weapons and scramjets require large boosters– Design is difficult due to
• viscous interactions• high temperatures• trajectory• predicting shock/fuselage interaction shape
– Airbreathing (scramjet) vehicles have a highly integrated airframe and propulsion system• Materials challenge
– Large heat flux and integrated heat loads requires thermal protection systems– Use of windows for sensors becomes a challenge
• Maneuverability– Maneuvering comes at the cost of speed, particularly for glide weapons
Stratolaunch LLC
Approved for Public Release
April 2021Page 33
IMPLICATIONS FOR DEFENSIVE SYSTEMS
• Hypersonic defensive weapons have all the same challenges as defensive weapons.• The issue comes down to decreased decision time for engagement
– Employment altitudes and maneuverability complicate find, fix, track, and target, engage, assess
