Presented By
Dehua Feng
The Design and Aero Thermodynamic
Analysis of An Inversely Derived
Scramjet Configuration
D. Feng, F. Ferguson, M. Atkinson, J. Mendez
North Carolina A&T university
Thermal & Fluids Analysis Workshop
TFAWS 2018
August 20-24, 2018
NASA Johnson Space Center
Houston, TX
TFAWS Aerothermal Paper Session
Outline
TFAWS 2018 – August 20-24, 2018 2
Introduction
Morphing Scramjet Model-Two Phase Approach
Phase I: Forebody
2D oblique shock theory
2D - 3D transfer
Validation
Summary of forebody
Phase II: Aft-Body
Modified Quasi 1-D tool development
Validation of the Quasi 1-D tool
Configuration test
Configuration results
Proof of concept
Introduction
TFAWS 2018 – August 20-24, 2018 3
By Kashkhan - CC BY-SA 3.0,
https://upload.wikimedia.org/wikipedia/commons/4/4f/Specific-impulse-kk-
20090105.png
• Higher specific impulse than rocket engines
• Does not need to carry it’s own oxidizer
• Potential for high reusability and practicality
over rockets
NCAT Focus: Optimized Scramjet Engine
o US, China, India, Europe are creating & designing concepts
o In US, Several exists, at US Research Agencies & Academia
o Our Concept at NCAT!
NASA - http://antwrp.gsfc.nasa.gov/apod/ap040329.html
Taking Humans to Space
Morphing Scramjet Model-Two Phase Approach
TFAWS 2018 – August 20-24, 2018 4
Drag Thrust
Optimized for Maximum ‘Thrust to Drag’ Ratio
2. Create An Internal 3D-Shape generator that incorporates
i. Aerodynamically Coupled Forebody: Inlet-Isolator (Mach 3-8)
ii. Oblique, Quasi-1D and Pseudo-Shock/Shock Train Relationships
i. Simplified Injector, mixing and combustor models
ii. Quasi-1D (Mach 3 – 8) Aerodynamics/Combustor/Nozzle
1. Create A 3D-Shape generator that incorporates
My Research Approach
Phase I: Fore-section
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The Conceptual Design Process
1. Create A 3D-Shape generator that incorporates
i. Aerodynamically Coupled Forebody-Inlet-Isolator (M 3-8)
ii. Oblique, Quasi-1D and Pseudo-Shock/Shock Train Relationships
Drag
2-D Oblique Shock Theory
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zx
A
C
B
qb
f
Mw >1.0
NCAT Inverse Design Method for the Forebody
Caret Waverider Design Concept
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y
x
A
W
H
B
B3
B4
B1
B2L
q
b
a
z
A1
3-D Steam Tube Flow Path
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A
B
C
D
xz
y
A
B
C
D
Hypersonic Inlets
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a) Rear View b) Rear View c) Side View
d) Isometric View e) Isometric View
Fig. 9: Illustration of A Morphing Ramjet-to-Scramjet Configuration
Testing Process For Fore-Section
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Assumed: A Given Flight Path
y = 0.0389x5 - 0.8115x4 + 6.5376x3 - 25.45x2 + 53.425x + 3.8234
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8
Alt
itu
de (
km
)
Velocity (km/s)
Lower
Upper
Mid
Poly. (Mid)
Compare
Design
Predictions
to CFD
Evaluation
Objective: Creation of Hypersonic Inlet Configurations with
predictive performance capability
Ideal: 2D & 3D
Viscous: 2D & 3D
Design inputs
Mach Number 5
Length of the Primary Shock Zone 1(m)
Shock Angle 17.5°
Cruising Flight Altitude f(M)
3-D Inlet Validation of Design Routines/Euler
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• Case 1: Ideal 3D
Velocity Distribution – CFD Code
The SBLI Challenges
1. Leading Edge & SBLI Effects – Conduct Systematic Geometric Manipulations
2. Isolator Sizing - Validate/Improve Billig’s ISTI Relations
1
1170150
Re2
2
41
in
inoutinout
Isolator M
PPPPH
H
L
q
q
12
Euler Flow Field Results
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Case 2: viscous effectDensity Field Pressure Field
Validation Data Along Isolator Centerline
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* Predictions
Fine Grid = 1,474,442 cells
Coarse Grid = 272,432 cells
Zoomed: Isolator Validation Data
*
*
**
*
*
*
*
*
*
*
*
*
*
*
*
**
**
Viscous & Inviscid Solution
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3-D Viscous Studies
16
Elements
• 6.7 M
Nodes
• 1,165,267
Estimated
Memory
• 14.75 GB
Case 4
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3-D Viscous Studies – Grid Generation
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Irregular grid with clustering
3-D CFD Studies – Internal Flow Path
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Viscous Modification of the Hypersonic Inlet
Inverse Design – Euler Model
Inverse Design – w/ Viscous Modifications
Transformed model based off viscous effects
Summary of Forebody Design & Analysis
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19
2. Create A Internal 3D-Shape generator that incorporates
i. Simplified Injector, mixing and combustor models
ii. Quasi-1D (Mach 3 – 8) Aerodynamics/Combustor/Nozzle
Thrust
Responsible for Thrust generation
Combustor-Nozzle Section/ Aft-Section
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20
Taylor Series
Solution: (a) Euler Method, (b)
Runge-Kutta (Thomas)
Modified Quasi 1-D Tool Development
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21
Area Only, Convergent Duct, Subsonic
Area(x) = 17.0 -
3.0x
y
x
M1 = 0.03
P1 = 300 kPa
T1 = 300 K
L = 5.0 m
Modified Quasi 1-D Tool Development (validation)
TFAWS 2018 – August 20-24, 2018
22
M1 = 0.5
P1 = 344737.865 Pa
T1 = 299.817 K
cf = 0.0005
P* = 161235.613 Pa
T* = 262.315 KD = 0.1524 m
L = 81.4578 m
Fanno Flow
Schematic of a constant area pipe (Bandyopadhyay, 2007)
Modified Quasi 1-D Tool Development (validation)
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23
Quasi 1D with Friction
1.27
m
5.08
m
D1 = 0.2286 m
M1 = 0.25
P1 = Pref = 344737.865
Pa
T1 = Tref = 299.817 K
cf = 0.0125
D2 = 0.3048
m
M2 = ?
P2 = ?
T2 = ?
6.35 m
Ref. Bandyopadhyay, 2007
Dt = 0.1524 m
Modified Quasi 1-D Tool Development (validation)
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24
25
Quasi 1-D Inlet Evaluation (M = 5-8)
Increasing Mach
Increasing Freestream Mach
Increasing Freestream Mach
Fore-section validation with modified Quasi 1-D tool
TFAWS 2018 – August 20-24, 2018
2. Create A Internal 3D-Shape generator that incorporates
i. Simplified Injector, mixing and combustor models
ii. Quasi-1D (Mach 3 – 8) Aerodynamics/Combustor/Nozzle
Thrust
Responsible for Thrust generation
Combustor-Nozzle Section/ Aft-Section
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26
Taylor Series
Solution: (a) Euler Method, (b)
Runge-Kutta (Thomas)
Quasi 1-D Tool
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27
Flow Path Simulation
285/17/2019
Forebody Inlet Isolator Combustor
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29
Combustor – Nozzle section / aft-section
• High speed aerodynamics is driving this design.
• This section is dominated by viscous effects,
• which results in a very complicated flow field.
• Conventional CFD tools cannot capture the flow
physics we’re after.
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30
We have Six influence coefficients :
Quasi 1-D Tool Usage
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Description Numbers Dimension
Flight Altitude 30.0 km
Mach Number 5.0
Wedge Angle 16.0 Degrees
Forebody Length 1.0 m
Fractional x & y Lengths of ID Values
Isolator Design Parameters 1.0 0.9
Combustor Design
Parameters
1.0 0.8
Nozzle Design Parameters 1.0 0.0
Design inputs:
Example with 3 different influences
31
TFAWS 2018 – August 20-24, 2018
Three Influences for Testing
Results Plots Of Flow Properties Distribution
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Distribution For Various Mach Number
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Thermo-Cycle For The Engine
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Thank You
Questions?
