Supersonic Wind and Imaging
Flow Tunnel
•Kendria Alt
•Joshua Clement
•Shannon Fortenberry
•Katelynn Greer
•David McNeill
•Charlie Murphy
•Matthew Osborn
•David Springer
Content
• Background
• Objective
• Tunnel Design
• Visualization Design
• Current Configuration
• Project Management
2
Objective
• Supersonic wind tunnel and flow
visualization system
• Operable by engineering
undergraduates
• Mach 1.5 – 3 in 0.5 increments
• Mach ±0.05 accuracy
• Customer: Dr. Brian Argrow
Home
3
Background
• Project attempted 6 years ago
– Failed due to choked flow before nozzle
• Commercially available supersonic wind
tunnels
– Aerolab 1” x 1” with Schlieren and 4 models
• $127,213.00
• Footprint ≈ 30 ft2
• Noise ≈ 120 dB
• Commercially available Schlieren system
– Focal length longer than cart top
– Low quality
– Edmund Optics
Home
4
Requirements
•Speeds
•Size and Weight
– Mach 1.5 - 3.0
– Volume < 30” x 42” x 36”
– ±0.05
– Weight < 100 lbs/cart top
•Steady State Run Time
– 2 cart tops available
– 5 sec
•Visualization
•Lab Session
– Used for Mach verification
– 12 runs at Mach 2
– Must see aerodynamic
without changing tanks
phenomena at front and
back of test object
– 1 run in 30 min
– Operable in temperatures •Test Section
of 20o - 80o F
– Area ≥ 1” x 0.25”
– Test 3 objects at all speeds
Home
5
Tunnel System
Valve
Regulator
Settling
Tank
Nozzle and Test
Section
Pressure
Reservoir
**Conceptual Representation Only
Matt Osborn
David Springer
Home
6
Tunnel Decision Flowdown
Helium
Commercial
Gas
Gas Nitrogen
Blowdown
Tunnel
Decisions
Direct
No Flow
Regulators
Nitrogen
Liquid
Nitrogen
Compressor
Multiple
Valves
Flow
Regulators
Oxygen
Second Tank
Liquid
Nitrogen
Air
Vacuum
Invar
Titanium Beta
III
K300 Nickle
Plexiglass
Glass
Polycarbonate
Flange / Bolts
Clamps
Slip
Connector
Round
Nozzle / Pipe
Threading
1 Valve
Gas Nitrogen
No Regulator
Grade 705
Zirconium
Regulator
Between
Tanks
Steady State
12 Nozzle /
Test Sections
4 Nozzles and 3
Test Sections
V
Pressure
Reservoir
R
ST
Conceptual Representation Only
Home
7
Tunnel Configuration Alternatives
Helium
Commercial
Gas
Multiple
Valves
Flow
Regulators
Oxygen
Gas Nitrogen
Blowdown
Direct
No Flow
Regulators
Nitrogen
Liquid
Nitrogen
Compressor
Second Tank
Liquid
Nitrogen
Air
Tunnel
Decisions
1 Valve
Gas Nitrogen
No Regulator
Vacuum
Steady
State
Invar
Titanium Beta
III
Plexiglass
Glass
Flange / Bolts
Clamps
Slip
Connector
12 Nozzle /
Test Sections
4 Nozzles and 3
Test Sections
K300 Nickle
Regulator
Between
Tanks
Grade 705
Zirconium
V
Polycarbonate
R
Round
Nozzle / Pipe
Threading
Pressure
Reservoir
ST
Conceptual Representation Only
Home
8
Tunnel Configuration Alternatives
Steady State (Appendix B)
Vacuum Tunnel (Appendix B)
Blowdown Tunnel
Not Feasible
Not Feasible
(Appendix B)
Atmosphere
Pressure Reservoir
Compressor
Nozzle
V
V
Nozzle
Nozzle
Atmosphere
•
•
Too large of a compressor at
Mach 3
Complicated
Vacuum Reservoir
•
•
•
Huge 21 ft3 required
Need large vacuum pump
Condensation and Icing
Atmosphere
•
•
•
Much smaller reservoir (high
pressure)
No condensation or icing
Commercial gas (no pumps)
Home
9
Initial Analysis Conclusions
Property
Units
Test Section Size
Mach Number
1.50
3.00
[in by 0.25 in]
1.00
1.00
Nozzle Size
[in by 0.25 in]
0.85
0.24
Nozzle Tolerance
[in]
0.0488
0.0225
Nozzle Temperature
[deg R]
444.2
447.2
Test Section Temp.
[deg R]
367.6
190.4
Temperature Difference
[deg R]
76.6
256.8
Static Pressure
[psi]
43.2
432.6
Mass Flow
[slugs/s]
0.0066
0.0183
Full Mach Range
Home
10
Gas Selection
Helium
Oxygen
Blowdown
Multiple
Valves
Flow
Regulators
Commercial
Gas
Gas Nitrogen
Tunnel
Decisions
Vacuum
Direct
No Flow
Regulators
Nitrogen
Gas Nitrogen
Liquid
Nitrogen
1 Valve
Second Tank
Compressor
Liquid
Nitrogen
Steady State
No Regulator
Air
Regulator
Between
Tanks
Invar
Titanium Beta
III
Plexiglass
Glass
Flange / Bolts
Clamps
Slip
Connector
12 Nozzle /
Test Sections
K300 Nickle
V
Grade 705
Zirconium
R
Polycarbonate
Round
Nozzle / Pipe
Threading
Pressure
Reservoir
ST
4 Nozzles and 3
Test Sections
Conceptual Representation Only
Home
11
Gas Selection
Specifics
Air
N2
O2
He
Weight
Score
Score
Score
Score
•Oxygen
eliminated on
safety
Safety
35%
3
3.25
0.5
3.25
Cost
25%
3
3.25
3.25
0.5
•Nitrogen
selected over air
based on cost
Mass
Flow
20%
2
2
1
5
• 2200 psi: $6.45
Mass per
Tank
20%
3
3
3.5
0.5
• 3500 psi: $138
Total
100%
2.76
2.92
1.81
2.32
• 6000 psi: $198
Conclusions
Nitrogen available in both liquid and gaseous forms.
Purchase through AirGas or on campus.
Home
12
Liquid vs. Gas Nitrogen
Helium
Multiple
Valves
Flow
Regulators
Oxygen
Gas Nitrogen
Commercial
Gas
Direct
No Flow
Regulators
Blowdown
Gas Nitrogen
Nitrogen
Second Tank
Liquid
Nitrogen
Compressor
Tunnel
Decisions
Air
Vacuum
Steady State
Invar
Titanium Beta
III
K300 Nickle
Plexiglass
Glass
Polycarbonate
Flange / Bolts
Clamps
Slip
Connector
Round
Nozzle / Pipe
Threading
12 Nozzle /
Test Sections
4 Nozzles and 3
Test Sections
1 Valve
No Regulator
Liquid Nitrogen
Regulator
Between
Tanks
Grade 705
Zirconium
V
Pressure
Reservoir
R
ST
Conceptual Representation Only
Home
13
Regulators vs. Second Tank
Helium
Flow
Regulators
Oxygen
Commercial
Gas
Blowdown
Multiple
Valves
Nitrogen
Liquid
Nitrogen
Compressor
Tunnel
Decisions
Direct
Gas Nitrogen
No Flow
Regulators
Gas Nitrogen
1 Valve
Air
Vacuum
Second Tank
Invar
Titanium Beta
III
K300 Nickle
Liquid
Nitrogen
Grade 705
Zirconium
No Regulator
Steady State
Regulator
Between
Tanks
Plexiglass
Glass
Polycarbonate
V
Flange / Bolts
Clamps
12 Nozzle /
Test Sections
Slip
Connector
R
Round
Nozzle / Pipe
Threading
4 Nozzles and 3
Test Sections
Pressure
Reservoir
ST
Conceptual Representation Only
Home
14
Regulators vs. Second Tank
8 Tanks – 8 Regulators
• Requirement
– 0.0183 slugs/s → 29,000 scfh
R
R
R
R
R
R
R
R
V
Conceptual Representations Only
• Tanks: 4000 scfh
– Minimum 8 tanks
• Regulators: 6000 scfh
– Minimum 6 regulators
– Each regulator > $300
• 48 Runs at Mach 2
• Constant test section properties
8 Tanks – 1 Regulator – Second Tank – 2
Valves
• Second tank
– 4 cubic feet @ 1000 psi maximum
– Can manufacture for ~ $700
V
R
V
• 12 Runs at Mach 2
• Properties in test section change
Appendix C
Home
15
Liquid vs. Gaseous Nitrogen
Helium
Commercial
Gas
Gas Nitrogen
Blowdown
Tunnel
Decisions
Gas Nitrogen
Direct
1 Valve
No Flow
Regulators
Nitrogen
Liquid
Nitrogen
Compressor
Multiple
Valves
Flow
Regulators
Oxygen
Second Tank
Air
Vacuum
No Regulator
Liquid Nitrogen
Invar
Titanium Beta
III
K300 Nickle
Plexiglass
Glass
Polycarbonate
Regulator
Between
Tanks
Grade 705
Zirconium
Steady State
Flange / Bolts
Clamps
12 Nozzle /
Test Sections
Slip
Connector
4 Nozzles and 3
Test Sections
V
R
Round
Nozzle / Pipe
Threading
Pressure
Reservoir
ST
Conceptual Representation Only
Home
16
Liquid vs. Gaseous Nitrogen
•
Gaseous Nitrogen
–
–
•
V
Liquid Nitrogen
–
R
V
8 Tanks – One Regulator – Two Gaseous Valves
8 Hoses and Manifold – Complicated ($$)
–
–
–
–
1 Tank –Cryogenic Valve – Heater Element – Gaseous
Valve
Hours of run time
11,430.67 BTU/hr → $200 heater
Liquid Nitrogen available on campus
Thermal Fatigue on 2nd Tank
V
•
V
Currently not enough information to decide
–
–
Parallel Paths
Drop Dead Date of Oct. 26
Home
17
Nozzle Material
Helium
Commercial
Gas
Gas Nitrogen
Blowdown
Tunnel
Decisions
Liquid
Nitrogen
Gas Nitrogen
Titanium
Beta III
Invar
Liquid
Nitrogen
Plexiglass
Flange / Bolts
Clamps
12 Nozzle /
Test Sections
Glass
Slip
Connector
4 Nozzles and 3
Test Sections
K300 Nickle
1 Valve
Second Tank
Air
Vacuum
Steady State
Direct
No Flow
Regulators
Nitrogen
Compressor
Multiple
Valves
Flow
Regulators
Oxygen
No Regulator
Regulator
Between
Tanks
Grade 705
Zirconium
V
Polycarbonate
R
Round
Nozzle / Pipe
Threading
Pressure
Reservoir
ST
Conceptual Representation Only
Home
18
Nozzle Material Selection
V∞
447.2°R
190.4°R
Not to Scale
•Temperature differences at throat and test section
• Contraction differences modify Mach number
Home
19
Nozzle Material Selection
Specifics
TiK-300
Invar
BetaIII
Ni
• CTE: Coefficient of
Thermal Expansion
• Specific Strength:
lightweight under
pressure
• Hardness affects
machinability
•Assumed 120 sec of
continuous Mach 2
flow
Grade
705 Zr
Weight
Score
Score
Score
Score
CTE
60%
0.8
4.2
2.1
2.9
σ/ρ
20%
4.1
1.7
2.5
1.7
Cost
10%
2.1
1.3
3.7
2.9
Hard
10%
1.7
2.5
2.5
3.3
Total
100%
1.7
3.2
2.4
2.7
Conclusions
• Sensitivity analysis supports Invar for CTE > 43%
Material Specs: Appendix D
Home
20
Test Section Sidewall
Helium
Commercial
Gas
Gas Nitrogen
Blowdown
Direct
No Flow
Regulators
Nitrogen
Liquid
Nitrogen
Compressor
Tunnel
Decisions
Multiple
Valves
Flow
Regulators
Oxygen
Gas Nitrogen
Second Tank
Liquid
Nitrogen
Air
Vacuum
Invar
Titanium Beta
III
K300 Nickle
Flange / Bolts
Clamps
12 Nozzle /
Test Sections
Slip
Connector
4 Nozzles and 3
Test Sections
Glass
No Regulator
Regulator
Between
Tanks
Grade 705
Zirconium
Steady State
Plexiglass
1 Valve
Polycarbonate
V
R
Round
Nozzle / Pipe
Threading
Pressure
Reservoir
ST
Conceptual Representation Only
Home
21
Test Section Material Selection
• Test section cross section
• Grey: Transparent windows
• Green: Metal
• Materials contract at different rates
190.4°R
Not to Scale
Home
22
Test Section Material Selection
Specifics
• k: Conductivity
affects condensation
• n: Refractive
Index - visualization
• % Visible transparency
• Hardness - scratch
resistance
Glass
Plexiglass Polycarbonate
Weight
Score
Score
Score
k
20%
1.7
4.4
3.9
n
20%
5
2.2
2.8
CTE
15%
5.5
2.5
2
% Visible
15%
2.8
3.9
3.3
σ/ρ
15%
1.7
3.9
4.4
Cost
10%
3.1
3.9
3
Hard
5%
4.5
3.3
2.2
3.37
3.42
3.21
Total
100%
•Assumed 120 sec of
continuous Mach 2
flow
Conclusions
• Sensitivity analysis shows Plexiglass and Glass ~50/50
Material Specs : Appendix D
Home
23
Test Section / Nozzle Structure
Helium
Commercial
Gas
Gas Nitrogen
Blowdown
Tunnel
Decisions
Direct
No Flow
Regulators
Nitrogen
Liquid
Nitrogen
Compressor
Multiple
Valves
Flow
Regulators
Oxygen
Second Tank
Liquid
Nitrogen
Air
Vacuum
Invar
Titanium Beta
III
Plexiglass
Glass
1 Valve
Gas Nitrogen
K300 Nickle
No Regulator
Regulator
Between
Tanks
Grade 705
Zirconium
Steady State
Polycarbonate
V
Flange / Bolts
Clamps
12 Nozzle / Test
Sections
Slip Connector
4 Nozzles and 3
Test Sections
R
Round Nozzle /
Pipe Threading
Pressure
Reservoir
ST
Conceptual Representation Only
Home
24
Test Section / Nozzle Structure
• Requirement: 3 objects, 4 Mach numbers each
• Test Section/Nozzle configuration
– 4 Nozzles with 3 interchangeable test sections
– 12 Fixed nozzle / test section combos
• Less complex
• Nozzle / Settling Tank Connection
– Round nozzle w/ pipe threads
– Slip connector
– Flanges w/ clamps
• Easy to use
• Quick change out of nozzle
Home
25
Additional Requirements & Risks
• Noise Constraints
– EH&S guidelines
– 85 dB
• Ability to Troubleshoot
– In the event of initial failure to achieve supersonic
flow
– Reservoir pressure and temperature measurements
• Risks
– Budget
– Manufacturing
– Safety
Home
26
Noise
•Requirement
Solution
– 85 dB at Walkways • Noise is Directional
– 20 - 30 ft from
– Small half booth
tunnel
•Empirical Data
– 65 -160 dB
• Test section 20x30
mm to 2x2 m
• 0.8 < M < 8
• Acoustic Foams
– 2 - 4” thick
– NRC 0.8 - 1.25
Ref [7]
• High Density Vinyl
Barriers
– STC 27 - 32
Ref [7]
• Foam - Vinyl Composites
Home
27
Troubleshooting Instrumentation
• Settling Tank Thermocouple
– Easily integrated with LabView
– K type
– NPT fitting for pressure vessels
• Settling Tank Pressure
Transducer
–
–
–
–
–
Ref [8]
Commercially available
Compact
Easily integrated with LabView
0 - 2000 psi
NPT fitting
• Pitot Tube Appendix E
Ref [9]
Home
28
Tunnel Risks
5
C
o
n
s
e
q
u
e
n
c
e
Cost
4
Nozzle
Design
LN2 Heater
3
Machining
Tolerances
Settling Tank
2
Volume
Constraint
1
Connections
1
2
3
Settling Tank
Thermal
Fatigue
Cryogenic
Valve
4
5
Likelihood
Home
29
Tunnel Risk
• Liquid Nitrogen Heater (11/01)
– Inadequate specifications
– Thoroughly research heater options
• Settling Tank Design and Thermal Fatigue (10/26)
– Inadequate specifications and cost
• Custom or in-house
– Contact vendors and Matt Rhode
• Cryogenic Valve (10/26)
– Inadequate specifications
– Continue dialog with AirGas vendor
Home
30
Visualization System
Kendria Alt
Josh Clement
Home
31
Visualization Decision Flowdown
Radial
Color
Shadowgraph
Visualization
System
Schlieren
Double
Pass
Straight
Achromatic
Fixed
Lens
Mount
Achromatic
Objective
Adjustable
Lens
Mount
Knife Edge /
Filter
Interchange
Horizontal
Black and
White
Linear
Color
Knife
Edge
Only
3-Axis
Adjustable
CCD
Focusing
Interferometer
Vertical
Black and
White
CMOS
FILM
FireWire
GPIB
2-Axis
Adjustable
Horseshoe
USB
Ethernet
Z
Commercial
Mount
Manufactured
Mount
2-Axis
Adjustable
Cart Base
Structure
Metal
Foundation
Plastic
Foundation
Plastic
Encasing
Aluminum
Encasing
Wooden
Encasing
3-Axis
Adjustable
Home
32
Schlieren, Shadowgraph,
Interferometer
Radial
Color
Shadowgraph
Visualization
System
Schlieren
Double
Pass
Achromatic
Fixed
Lens
Mount
Straight
Achromatic
Objective
Adjustable
Lens
Mount
Vertical
Black and
White
Knife Edge /
Filter
Interchange
Horizontal
Black and
White
Linear
Color
Knife
Edge
Only
3-Axis
Adjustable
CCD
Focusing
CMOS
FILM
FireWire
GPIB
2-Axis
Adjustable
Horseshoe
Interferometer
USB
Ethernet
Z
Commercial
Mount
Manufactured
Mount
2-Axis
Adjustable
Cart Base
Structure
Metal
Foundation
Plastic
Foundation
Plastic
Encasing
Aluminum
Encasing
Wooden
Encasing
3-Axis
Adjustable
Home
33
Schlieren, Shadowgraph,
Interferometer
• Shadow Graph
– 2nd derivative of density
– Simplest method
– Lower contrast
• Schlieren
– 1st derivative of density
– Small increase in complexity
– Increase in contrast
• Interferometer
– Density
– Sum of path differences < λ /10th
– Least familiarity
Example Pictures: Appendix F
Home
Ref [1] 34
Schlieren Layout
Radial
Color
Vertical
Black and
White
Horizontal
Black and
White
Linear
Color
Double Pass
Visualization
System
Shadowgraph
Achromatic
Fixed
Lens
Mount
Schlieren
Achromatic
Objective
Adjustable
Lens
Mount
Straight
Knife Edge /
Filter
Interchange
Knife
Edge
Only
3-Axis
Adjustable
CCD
Focusing
CMOS
FILM
FireWire
GPIB
2-Axis
Adjustable
Interferometer
Horseshoe
Commercial
Mount
USB
Ethernet
Manufactured
Mount
Z
2-Axis
Adjustable
Cart Base
Structure
Metal
Foundation
Plastic
Foundation
Plastic
Encasing
Aluminum
Encasing
Wooden
Encasing
3-Axis
Adjustable
Home
35
Schlieren Layouts
•Z
• Precise angles prevent
coma aberration
• Large footprint
•Double Pass
• Nonparallel light in
test section
• Advantage of size
•Straight Schlieren
• Smaller focal length
• Ease of integration
Ref [2]
Home
36
Schlieren Layout
Double
Pass
Z
Horseshoe
Straight
Weight
Score
Score
Score
Score
Clarity
35%
1
4
1
4
Size
20%
3
2
1
4
Setup
15%
3
1
2
4
Stability
10%
3
1.5
1.5
4
Cost
10%
4
2
2
2
Time to
Build
5%
3
2
2
3
Ease of
Design
5%
4
2
1
3
Total
100%
2.45
2.5
1.35
3.7
Specifics
• Clarity: most important,
verification
• Size: must be able to fit on
cart top
• Stability: must be able to
withstand movement without
quality loss
•Time to build: number of parts,
complexity, and tolerances
•Ease of design: depth of
calculations
Conclusions
•Straight setup has high accuracy and small footprint
•Straight setup is easy to use and calibrate
Home
37
Visualization Decision Flowdown
Radial
Color
Achromatic
Shadowgraph
Visualization
System
Fixed
Lens Mount
Knife Edge /
Filter
Interchange
Double
Pass
Schlieren
Straight
Interferometer
Horseshoe
Achromatic
Objective
Vertical
Black and
White
Horizontal
Black and
White
Linear
Color
Knife
Edge
Only
3-Axis
Adjustable
2-Axis
Adjustable
Adjustable
Lens Mount
CCD
CMOS
FILM
FireWire
GPIB
Focusing
USB
Ethernet
Z
Commercial
Mount
Manufactured
Mount
2-Axis
Adjustable
Cart Base
Structure
Metal
Foundation
Plastic
Foundation
Plastic
Encasing
Aluminum
Encasing
Wooden
Encasing
3-Axis
Adjustable
Home
38
Lenses
• Types
– Focusing Lens
• Different wavelengths have different focal lengths
– Achromatic Lens
• Reduces chromatic aberration
• Dual lenses
– Achromatic Objective Lens
• Changes orientation of aberrations
• Two lenses separated by air or oil
• Expensive ~$500 to $1000
• Specifications
– Diameter: 3 in
– Focal Length: 0 to 6 in
Home
39
Refraction Detection Method
Radial Color
Visualization
System
Shadowgraph
Double
Pass
Achromatic
Fixed
Lens
Mount
Schlieren
Straight
Achromatic
Objective
Adjustable
Lens
Mount
Interferometer
Horseshoe
Horizontal
Black and
White
Vertical Black
and White
Knife Edge /
Filter
Interchange
Linear Color
Knife Edge
Only
3-Axis
Adjustable
CCD
Focusing
CMOS
FILM
FireWire
GPIB
USB
2-Axis
Adjustable
Ethernet
Z
Manufactured
Mount
Commercial
Mount
2-Axis
Adjustable
Cart Base
Structure
Metal
Foundation
Plastic
Foundation
Plastic
Encasing
Aluminum
Encasing
Wooden
Encasing
3-Axis
Adjustable
Home
40
Refraction Detection
• Knife Edge
– Clear black and white
visualization
– Vertical or horizontal
placement show different
details
Ref [14 ]
• Radial Color Filter
– Density variations stand out
• Linear Color Filter
Ref [15 ]
– Provides color and intensity
differences for high and low
densities
Ref [16 ]
Home
41
Refraction Detection
• Manual Three Axis Support
– Easy calibration within 7.87 10-5 in
– Calibration performed once per semester
– Cost ~ $500
• Motorized Mounts
– Expensive ~ $1000
– Accurate to 3.94 10-3 in
• Interchange
– Provide 3 filters for the 4 visualization methods
– Filters mount on a 3-axis adjustable support
Home
42
Capture Method
Radial
Color
Double
Pass
Achromatic
Fixed
Lens
Mount
Schlieren
Straight
Achromatic
Objective
Adjustable
Lens
Mount
Interferometer
Horseshoe
Shadowgraph
Visualization
System
Vertical
Black and
White
Knife Edge /
Filter
Interchange
Horizontal
Black and
White
Linear
Color
Knife
Edge
Only
3-Axis
Adjustable
CCD
Focusing
Z
CMOS
FireWire
Commercial
Mount
Cart Base
Structure
Metal
Foundation
2-Axis
Adjustable
FILM
GPIB
Aluminum
Encasing
Ethernet
Manufactured
Mount
Plastic
Foundation
2-Axis
Adjustable
Plastic
Encasing
USB
3-Axis
Adjustable
Wooden
Encasing
Home
43
Capture Method
Specifics
Film
CMOS
CCD
Weight
Score
Score
Score
Frame/sec
30%
1
4.5
4.5
Remote Control
30%
0.5
4.75
4.75
Resolution
20%
5
2.5
2.5
Cost
20%
3.12
3.12
3.76
Total
100%
2.1
3.9
4.0
•Requirement: 2 fps
•Resolution normalized
to 3 Mega pixels
•Frames per second
normalized to 20 fps
•Prices normalized to a
$1500 camera
Conclusions
•CMOS and CCD comparable
Ref [18]
•Final decision based on individual specifications
Home
44
File Transfer Method
USB
Specifics
• Speed
normalized to 10
Mbytes/s
• Cable cost
includes max
length and
durability
• Only USB and
GPIB are
immediately
compatible with
LS
• FireWire cards
$50
• Ethernet
activation- $350
GPIB FireWire Ethernet
Weight
Score
Score
Score
Score
LabStation
Compatibility
30%
3.5
3.5
2
1
Cost
30%
3
2.5
3
1.5
LabView
Compatibility
20%
2
2.5
5
0.5
Cable
10%
3
2.5
2
2.5
Speed
10%
2.5
1
5
1.5
Total
100%
3
2.55
3.2
1.25
Conclusions
• The ideal file transfer method will be FireWire
• Other constraints may require a less desirable
method
Home
45
Camera Adjustability
• 2-Axis Adjustability
– Ability to focus 3rd dimension with camera
– Ease of use
– Locking
• Commercial Mount
– Expensive ~ $350
• Custom Mount
– Complicated design
– Intricate Fabrication
Ref [12]
Home
46
Schlieren Base and Encasing
Radial
Color
Shadowgraph
Visualization
System
Schlieren
Double
Pass
Achromatic
Fixed
Lens
Mount
Straight
Achromatic
Objective
Adjustable
Lens
Mount
Vertical
Black and
White
Knife Edge /
Filter
Interchange
Linear
Color
Knife
Edge
Only
3-Axis
Adjustable
CCD
Focusing
Interferometer
Horizontal
Black and
White
CMOS
FILM
FireWire
GPIB
2-Axis
Adjustable
Horseshoe
USB
Ethernet
Z
Commercial
Mount
Manufactured
Mount
2-Axis
Adjustable
3-Axis
Adjustable
Cart Base
Structure
Metal
Foundation
Plastic
Foundation
Plastic
Encasing
Aluminum
Encasing
Wooden
Encasing
Home
47
Schlieren Base and Encasing
• Base
– Use the cart top
– Use a metal foundation to secure optical components
• Encasing
– Plastic is light and inexpensive
• Metal and wood heavy
– Protection of lenses and camera
• Students
• Dust, scratches, etc.
– Light tight during testing
– Window for educational purpose
– Opening for T.A.s to access instrumentation
Home
48
Visualization Risks
C
o
n
s
e
q
u
e
n
c
e
5
Lenses
4
Internal
Interference
Aberration
3
Optical Mounts
Camera
External
Interference
2
1
1
2
3
Calibration
Encasing
4
5
Likelihood
Home
49
Current Configuration
Home
50
Cost Estimates
Wind tunnel
Item
Qua
Price
Cost
Schlieren
Visualization System
CCD Camera PL-A781/2
1
1,583.00
1,583.00
Achromatic Objective Lenses
2
700.00
1,400.00
Optical Cell Mounts 3"
2
20.00
40.00
Knife Edge
1
10.00
10.00
Knife Edge Mount
1
295.00
295.00
Student Made Color Filter
2
10.00
20.00
Light source (straight filament)
1
4.99
4.99
Light mount with slit
1
10.00
10.00
Structure and Encasing
12 Nozzles @ 6x2x2
Stock Invar @ 6x6x1
4
185.00
740.00
Spare Invar Stock
2
185.00
370.00
Mills
2
28.45
56.89
Stock Invar @ 6x6x1
1
185.00
185.00
Optical Grade Polycarbonate @ 3x2x0.5
24
3.00
72.00
Spare Polycarbonate
4
3.00
12.00
O rings
40
0.50
20.00
Sound Booth
1
100.00
100.00
12 Test Sections @ 3x2
Misc.
Aluminum Stock for machining mounts
1
9.19
9.19
100 1/8" Bolts
3
15.00
45.00
Black Plexiglas sheet 12x12 (10 sheets)
1
46.90
46.90
100 1/8" Nuts
3
12.00
36.00
Aluminum 1" square tubing
1
143.46
143.46
3
12.00
36.00
Box of 25 head machine Skews
1
8.33
8.33
Black Silicone cocking
1
1.95
1.95
Pressure Transducers
1
205.00
205.00
Thermocouples
1
35.00
35.00
1
100.00
100.00
Additional Hardware
1
100.00
100.00
Nitrogen tank
16
6.51
104.16
Settling Tank
1
500.00
500.00
Pressure Regulator
1
200.00
200.00
Linkages
15
20.00
300.00
Insulated Tubing (60 feet)
1
100.00
100.00
Manual On/Off Valve
1
150.00
150.00
Pneumatic Valve
1
795.00
795.00
Misc.
Prototype
Gas
100 1/8" Washers
Data Collection
TOTAL +25%
Initial Total
Contingency (25%)
TOTAL
$9,134.21
$7,534.87
$1,883.72
$9,418.59
Applying for UROP, EFF, Department
and Dean’s Fund resources.
Home
51
Base Deliverables
Base:
2 Invar Nozzles / Test Sections
Linkages for 1 tank
$4000
Consequence
Mach Accuracy not guaranteed at all
temperatures
Only 1 run tank, wasteful
1 Settling Tank
1 Manual Valve
No one button start / stop
1 Pressure Regulator
1 Low Resolution Camera
1 Pair Low Quality Mirrors
Difficult Mach Measurement
Can not verify Mach accuracy
1 Set Fabricated Optical Mounts
No guarantee on performance or
durability
1 Knife Edge
Black and White Schlieren Only
Fabricated Color Filter
Home
52
Deliverable Upgrades
Base:
$4000
Additional Nozzles and Test Sections
Additional Cost
$77.10 each
Manifold to accommodate 8 tanks
$300
1 Pneumatic Valve
$800
1 Pair High Quality Lenses
$712
1 High Resolution Camera
$900
Commercial Knife Edge Mounts
$300
Settling Tank Pressure and Temperature Sensors
$340
Storage Case for Test Sections and Optical Components
$280
Commercial Color Filter
$710
Commercial Lens and Camera Mounts
$500
Home
53
SWIFT
Responsibility Breakdown
Project Manager
David McNeill
Assistant Project Manager
Matt Osborn
Safety Engineer
David Springer
Web Master
Matt Osborn
Systems Engineer
Shannon Fortenberry
Fabrication Engineer
Charlie Murphy (WT)
Katelynn Greer (Vis)
Aerodynamics Lead
Matt Osborn
Structure Lead
David Springer
Human Factors
Joshua Clement
Visualization Team
Tunnel Team
Gas Lead
Shannon Fortenberry
CFO
Kendria Alt
Electronics Lead
Charlie Murphy
Optics Lead
Joshua Clement
Structure Lead
Kendria Alt
Capture Lead
Katelynn Greer
Home
54
Tunnel Team
Responsibility Breakdown
Tunnel Team
Aerodynamics
Nozzle / Test Section
Fluid
Settling Tube
Transportation
Structure
Nozzle, TS,
Settling Tube
Selection
Electronics
Acoustic
Enclosure
Dimensions
Size
Regulation
Quantity
Material
Material
Computer Interface
Object Placement
Straightening
Valves
Phase
Thermal
Contraction
Support
Fluid Heater
Massflow
Velocity
Storage Vessel
Cost
Nozzle / Settling
Tube Interface
Transfer Method
Settling Tube
Sensing
Acoustics
Heat Addition
Tubing
Type
Transparency
Diffuser
Pressure / Temp.
Linkages
Pressure Capacity
Home
55
Visualization Team
Responsibility Breakdown
Visualization Team
Filtration
Lens/Mirror
Layout
Sensitivity
Capture
Structures
Optics
Reflectivity
Camera / Knife Edge
Support
Protection
Electronics
Method
Neccessity
Adjustment
Purchase /
Fabricate
Transparency
Resolution
Transfer Rate
Purchase /
Fabricate
Pointing
Accuracy
Collapsibility
Frames / Sec
Camera Control
Strength
TS / Protection
Interface
Cost
Transfer
Method
Size
Size
Sensitivity
Light Source
Focal Length
Method
Pointing
Tolerance
Mirror Support
Aperture
Home
56
Semester Schedule
Home 57
Spring Schedule
Home
58
References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Merzkirch, Wolfgang. Flow Visualization. New York: Academic
P, 1974. 62-115.
Smits, A. J., and T. T. Lim. Flow Visualization Techniques and
Examples. Covent Garden: Imperial College P, 2000. 205-243
Shevell, Richard S. Fundamentals of Flight. 2nd ed. Upper
Saddle River: Prentice Hall, 1989
Wikipedia.org
http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml
NACA TN No. 1651,
http://naca.larc.nasa.gov/reports/1948/naca-tn-1651/, accessed:
09/25/2006
Matweb.com
http://www.omega.com/ppt/pptsc.asp?ref=TC-NPT
http://www.omega.com/pptst/px302.html
http://www.efunda.com/designstandards/sensors/pitot_tubes/pi
tot_tubes_theory.cfm
Home
59
References
11. Mott, Robert. Applied Fluid Mechanics. 6th ed. Upper
Saddle River: Prentice Hall, 2006 (eq 18.14)
12. http://www.edmundoptics.com/onlinecatalog/displayprod
uct.cfm?productID=1580&search=1, October 9, 2006
13. http://www.mne.psu.edu/psgdl/FullScaleSchlieren.pdf
14. http://www.mne.psu.edu/psgdl/highspeedshockmovie.pdf
15. http://www.mne.psu.edu/psgdl/ASME_%20shockwave.pdf
16. http://www.mne.psu.edu/psgdl/FSSISFV7_updated.pdf
17. http://www.ioffe.rssi.ru/GASDYN/Image4.jpeg
18. http://www.edmundoptics.com/onlinecatalog/displayprod
uct.cfm?productID=2716&search=1
Home
60
Tunnel
4. Background
5. Requirements
7. Tunnel Decision Flowdown
9. Tunnel Configuration Alternatives
10. Initial Analysis Conclusions
12. Gas Selection
15. Regulators vs. Second Tank
17. Liquid vs. Gaseous Nitrogen
19. Nozzle Material Selection (Diagram)
20. Nozzle Material Selection (Trade Study)
22. Test Section Material Selection (Diagram)
23. Test Section Material Selection (Trade Study)
25. Test Section/Nozzle Structure
26. Additional Requirements & Risks
27. Noise
28. Troubleshooting Instrumentation
29. Tunnel Risks (5x5)
30. Tunnel Risk (Mitigations)
Visualization
32. Visualization Decision Flowdown
34. Schlieren, Shadowgraph, Interferometer
36. Schlieren Layouts
37. Schlieren Layout (Trade Study)
39. Lenses
41. Refraction Detection
40. Refraction Detection
44. Capture Method
45. File Transfer Method
46. Camera Adjustability
48. Schlieren Base and Encasing
49. Visualization Risks (5x5)
50. Current Configuration
Budget
51. Cost Estimates
52. Base Deliverables
53. Deliverable Upgrades
Team Management
54. SWIFT Responsibility Breakdown
55. Tunnel Team Responsibility Breakdown
56. Visualization Team Responsibility Breakdown
57. Semester Schedule
58. Spring Schedule
Appendices
62. Appendix A Trade Study Sensitivity Analysis
63. Appendix B Assumptions and Key Equations
64. Appendix B Steady State Tunnel
67. Appendix B Vacuum Tunnel
69. Appendix B Blowdown Tunnel
74. Appendix C Gas Appendices
77. Appendix D Material Selection
79. Appendix E Pitot Tube
81. Appendix F Visualization Examples
83. Appendix G Single Mirror Schlieren
84. Appendix H Refraction Detection Focal Length Sensitivity
86. Appendix I Measurement Feasibility
87. Appendix J Future Consideration Nozzle
61
Appendix A
Trade Study Sensitivity Analysis
Analysis
Choice
1
Choice
2
Choice
3
Choice
4
Weight
Score
Score
Score
Score
Criteria 1
60%
2
4
3
1
Criteria 2
20%
1
3
2
4
Criteria 3
10%
2
4
3
1
10%
3
2
4
3
100%
1.9
3.6
2.9
1.8
• Sensitivity of
weights, not scores
• Lower subjectivity
in scores
• Varied weights and
Criteria 4
recalculated totals
• Investigated
weight combinations
that yielded different
results
Total
Conclusions
• Removed most subjectivity from trade studies
• Result often unchanged
Home
62
Appendix B
Assumptions and Key Equations
• Assumptions
X 0  stagnation condition
(for the preliminary analysis only)
– Isentropic Flow
– Ideal Nozzle
– The Gas was Dry Air
R(air )  1718
c p (air )  6006
X i  stream condition
1  1
0    1 2 
 1 
Mi 
i 
2

slug R
  1
T0
 1 2
 1
Mi
Ti
2
ft-lb
slug R
ft-lb
p0    1 2 
 1 
Mi 
pi 
2

1  2    1 2 
 Ai 
M 
 *  2 
1 
2

A 
M i   1 
2
 1 /  1
a  RT
Vi  M i ai
m i  iVi Ai
Pi  i RTi
Home
63
Appendix B
Steady State Tunnel
• Steady Flow Compressor
– Obtain Compression Ratio
p0    1 2 
 1 
Mi 
pi 
2

Compressor
  1
• Axial Compressor
– Used in Jet Engines
– Expensive and Complicated
• Centrifugal Compressor
– Turbochargers
– Common and Fairly Cheep
Nozzle
Atmosphere
Home
64
Appendix B
Steady State Tunnel at Mach 2
Observations
•Pressure Ratio
Patm = 2116.2
[lb/ft2]
Ρatm = 0.00238 [slugs/ft3]
Tatm = 518.69
[ºR]
M*
S*
p*
ρ*
T*
=
=
=
=
=
1
0.1481
8747.3
0.00654
778.0
[in2]
[lb/ft2]
[slugs/ft3]
[ºR]
Test Section
•7.82
•Test sec. temp. is
room temperature
Axial
Compressor
P0 = 16558 [lb/ft2]
ρ0 = 0.1032 [slugs/ft3]
T0 = 933.64 [ºR]
•518.7 ºR
•Energy required
is relatively low
•31.1 kW
Mt
St
pt
ρt
Tt
at
Vt
=
=
=
=
=
=
=
m=9.21 e-3
[slugs/s]
2
0.25
2116.2
0.00238
518.7
1117.0
2233.9
[in2]
[lb/ft2]
[slugs/ft3]
[ºR]
[ft/s]
[ft/s]

 T   1
p
CPR  0   0 
 7.82
patm  Tatm 
CW  c p T0  Tatm   3201
BTU
 31.1kW
slug
Need high compression ratio even at Mach 2. At Mach
3, would need a compression ratio of 36.73.
Additionally, temperature in the test section is close to
room temperature.
Home
65
Appendix B
Steady State Tunnel at Mach 2
Observations
•Question:
Could stock parts from
a turbocharger be
used?
•Max Compression ~ 3
•3 turbos at M=2
•12 turbos at M=3
•Mass Flow much larger
than needed.
•Cost
•$300-1000 per unit
Ref [5]
Ref [4]
Conclusions
A steady state tunnel is not feasible to meet
the requirements. Would need ideally 12
turbos, at Mach 3, in series to meet the mass
flow, but the compression ratio probably
decreases as p0 goes up.
Home
66
Appendix B
Vacuum Tunnel
• Commonly used in SSWT
applications
• Vacuum Reservoir must
be blow atm. pressure.
• Would to purchase
vacuum tanks.
– Not available from a
vendor.
Atmosphere
Nozzle
V
Vacuum Reservoir
Home
67
Appendix B
Vacuum Tunnel Mach 2
M*
S*
p*
ρ*
T*
Observations
•Tt = 288.2 ºR
•Condensation or
ice in test section
•Need 21 cubic feet of
tank volume for one
10 sec. run
Standard
Atmosphere
p0 = 2116.2
[lb/ft2]
ρ0 = 2.3769e-3 [slugs/ft3]
T0 = 518.69
[ºR]
Test
Section
Mt
St
pt
ρt
Tt
at
Vt
=
=
=
=
=
=
=
2
0.25
270.5
5.47e-4
288.2
832.5
1665.0
=
=
=
=
=
1
0.1481
1117.9
1.5068e-3
432.24
[in2]
[lb/ft2]
[slugs/ft3]
[ºR]
Settling
Reservoir
m = 1.58 e-3
[slugs/s]
[in2]
[lb/ft2]
[slugs/ft3]
[ºR]
[ft/s]
[ft/s]
Vacuum
Reservoir
•Need to buy and Conclusions
store
A vacuum tunnel is not feasible. A custom or multiple
•Need vacuum pump stock tanks would need to be purchased, none of which
would meet storage requirements. Additional
to evacuate air
complexity in the vacuum pump, and condensation or
icing in the flow tube.
Home
68
Appendix B
Blowdown Tunnel
• A variety of dried
gases feasible
Pressure Reservoir
– Eliminates icing or
condensation issues
V
• Use commercially
available tanks
– Do not need to store
– Do not need a
compressor
Nozzle
Atmosphere
Home
69
Appendix B
Blowdown Tunnel at Mach 2
M*
S*
p*
ρ*
T*
Observations
• One 10 sec run
with 3.14 ft3 (one
tank and no
regulator)
• 12 ten second
runs: 2 tanks with
regulated flow
Prssure
Tank
=
=
=
=
=
1
.1481
8747.3
0.0118
432.2
[in2]
[lb/ft2]
[slugs/ft3]
[ºR]
Settling
Tube
S0
P0
ρ0
T0
V0
=
=
=
=
=
7.06
16558
0.0186
518.69
13.5
[in2]
[lb/ft2]
[slugs/ft3]
[ºR]
[ft/s]
ptank = 288000 [lb/ft2]
ρtank = 0.3232 [slugs/ft3]
Ttank = 518.69 [ºR]
Test
Section
m = 0.0124
[slugs/s]
Mt = 2
St = 0.25
pt = 2116.2
ρt = 0.0043
Tt = 288.2
at = 832.5
Vt = 1665.0
[in2]
[lb/ft2]
[slugs/ft3]
[ºR]
[ft/s]
[ft/s]
*Not to Scale
Conclusions
A blowdown tunnel is feasible. Dried compressed gas
eliminates icing in the tunnel. Renting tanks
eliminates storage concerns and the need for a
compressor.
Home
70
Appendix B
Blowdown Tunnel Static Pressure
Observations
•Atm. pressure in test section
p0    1 2 
 1 
Mi 
pi 
2

  1
Observations
•Reservoir Temp. is Room Temp.
T0
 1 2
 1
Mi
Ti
2
Home
71
Appendix B
Blowdown Tunnel Throat Area
Observations
Observations
This is a unit depth Area, since at
any point the nozzle is 0.25 inches
deep.
•Nozzle Tolerance if Mach tolerance
is ±0.05
1  2    1 2 
 Ai 
M 
 *  2 
1 
2

A 
M i   1 
2
 1 /  1
Home
72
Appendix B
Blowdown Tunnel Mass Flow
Observations
Mass flow increases with Test
Section Area and Mach Number
Home
Observations
•At the nominal test section area
73
Appendix C
Volumeflow Conversion
Patm _ s Ta
Qa  Qs
Patm  Pa Ts
Ref [11]
Qa
Volume Flow Rate at Actual Conditions
Qs
Volume Flow Rate at Standard Conditions
Patm_s
Standard Absolute Atmospheric Pressure
Patm
Actual Absolute Atmospheric Pressure
Pa
Actual Gage Pressure
Ta
Actual Absolute Temperature
Ts
Standard Absolute Temperature
Home
74
Appendix C
No Settling Tank
•Assumptions
•Adiabatic, Polytropic,
Expansion


P1V1  P2V2
•Tank specs
•8.5” diameter
•50” height
•2000 psi
•Venting straight from
tank through nozzle
and test section •Conclusions
•12 tanks for 12 runs of 6 sec at Mach 2
•Higher Pressure
•Increased structure
•More expensive valves and linkages
Home
75
Appendix C
Settling Tank Optimization
Contours: Number of Tanks
for 12 runs at Mach 2
•Assumptions
•Adiabatic, Polytropic,
Expansion


P1V1  P2V2
•Tank Specs
•8.5” diameter
•50” height
•2000 psi
•Conclusions
•Settling tank: 4 ft3 at 450 psi for Mach 2
•8 tanks required for 12 runs at Mach 2
•Pressure increases to 1000 psi (still 4 ft3) for Mach 3
Home
76
Appendix D
Nozzle Material Selection
Options
• Matweb.com
– Invar
– Titanium Beta III
– K-300 Nickel
– Grade 705 Zirconium
Thermal Expansion (um/mC)
Specific Strength (Mpa/g/cc)
Cost $/lb
Hardness (vickers)
Invar
Titanium Beta III K-300 Nickel Alloy
1.3
7.6
6.8
60
436.89
122.29
215
150
67
900
970
903
Grade 705 Zr
6.3
58.85
80
638
Ref [7]
Home
77
Appendix D
Test Section Material Selection
Options
• Plexiglass
• Polycarbonate
• Glass
Plexiglass Polycarbonate
Glass
Thermal Expansion (um/m-C)
67.4
69.5
25
Thermal Conductivity (W/m-K)
0.17
0.2
1.17
Refactive Index
1.48
1.59
1.54
% Visible Allowed
91.7
88
87
Specific Strength (Mpa/g/cc)
50
52.08
38.7
Cost ($/lb)
Hardness Rockwell M
79.2
75.7 205 (vickers)
Ref [7]
Home
78
Appendix E
Pitot Tube
• Replacement Mach number verification
• Compressibility corrections required
– Factors are empirical
• Measurements made with transducers
or manometer
Home
79
Appendix E
Pitot Tube
Ref [10]
Home
80
Appendix F
Visualization Considerations
Ref [14]
Home
81
Appendix F
Visualization Considerations
Ref [17]
Home
82
Appendix G
Single Mirror Schlieren
“Well, for example, suppose you place a 2-D wedge in the test section of your
wind tunnel. With parallel light and good alignment you will see the wedge in
silhouette and sharp lines representing the oblique shocks it generates, since
the planar shocks will be aligned with the optical beam direction. Not so if
you use non-parallel light: then the shocks (and all other flow features) will
have an apparent ‘thickness’; although they are extremely thin in nature. This
is so misleading that essentially no one ever does this in M>1 wind tunnel
practice.”
-Gary S. Settles
Ref [13]
Home
83
Appendix H
Refraction Detection
Focal Length Sensitivity
Test
Section
Original Ray
Focal Length
•Short focal length decreases footprint
•Long focal length increases tolerance
Home
84
Appendix H
Refraction Detection
Focal Length Sensitivity
•Contours: Amount
of Refraction (in)
Home
85
Appendix I
Measurement Feasibility
• Thin boundary layer
• Worst case is ± .33 degrees
• High resolution camera is needed for
non-pixilated zooms
Home
86
Observations
Appendix J
Future Consideration
Nozzle
•Interface to settling tank
same as test cross-section
•1 inch by 0.25 inches
•Throat-area determined
•Depth 0.25 inches (2-D)
•Width determined by
1  2    1 2 
 Ai 
M 
 *  2 
1 
2

A 
M i   1 
2
 1 /  1
Key Variables
•Shape of sidewalls
•Connect the dots…
•Method known, but
shape not yet
determined
Home
87
Appendix J
Future Consideration
Nozzle Design Methods
Observations
• Three regions
1. Contraction
2. Sonic pre-inflection
  Prandtl - Meyer expansion angle
v


 1
 1 2
arctan
M  1  arctan M 2  1
 1
 1
3. Sonic post-inflection
  shock wave angle
  deflection angle
   1M 2

cot   tan  
 1
2
2
2
M
sin


1




Home
88
Appendix J
Future Consideration
Nozzle Design Methods
Design Methods
Design Assumptions
•Busemann’s Method – Assume
initial curve and adjust
•In-viscid Flow – No boundary layer
effects, but…
•Puckett’s Method – Start at
inflection point work both ways
•Eliminates Navir Stokes equations
•Foelch’s Method – Same as
Puckett’s except analytic
•Fairly accurate, especially for short
nozzles.
•Correction factors for boundary
layer thickness
Home
89