2. Overview
• More detailed intro to
Hyperloop
– Background
– Design Process/Course Objectives
– Video
– Year in Review (Design Weekend,
Qatar etc)
• Old: Design Weekend
Presentation
– Structure
– Levitation
– Propulsion
– Braking
– IEES
– Controls
2
• New Design:
– Structure redesign and
improvements
– Reevaluation of Air
Bearings/Integration into prev.
Design
– Improved EMS system
– Evaluation of Switched Reluctance
Motors
– Piston Brakes, Sled Redesign
– IEES redesign, separation of
function
– Full Dynamic Model of EMS system
– Modeling and sensors for air bearing
sensors
• Closing Remarks and Conclusions
– Design Process takeaways
• Open floor to Questions
3. Team Description and Members
• Hullabaloop design team is structured under the course ENGR 401/402, a two semester interdisciplinary senior
design class at Texas A&M University specifically geared towards the Hyperloop competition.
• Hullabaloop performed this design as if we were a “Design Company” in charge of designing a “Full Scale Hyperloop
System”, including sizing the tube diameter. This design will be scaled down to be built for the test track.
• Team Advisors:
– Dr. William Schneider, Zachry Professor of Engineering Practice | Senior Engineer at NASA (ret.), 38 years experience
– Dr. Andrea Strzelec, Assistant Professor, Department of Mechanical Engineering
• Team Members:
3
• Michael Alvarez
• Tim Austin
• Justin Benden
• Andrew Bradley
• Matt Campbell
• Will Davis
• Ian de Vlaming
• Christian DeBuys
• Deepak Dhankani
• Giang Do
• JP Elizondo
• Kelsey Fieseler
• Clayton King
• Brandon Kinsey
• Matt Martinez
• Jim McCabe
6. Year in Review
• Students elected for interdisciplinary Hyperloop
design course over summer
• Broke up into 2 studios with 4 groups to facilitate
ideas from all 8 groups
• Recombined into one, 40 person team
• Work through October to January for Design
Weekend
• Qatar Trip
• Work on advancing design and completing 402
6
11. The Design Process
General Specific More Specific
Need Statement
Need Analysis
Function
Function Structure
Functional Requirements
Performance Requirements
Conceptual Design
Preliminary Design
Final Design
11
12. Need Statement
There is a need for a high speed transportation pod that
can travel in the low pressure Hyperloop tube. The pod
must have propulsion, stability, navigation, and braking
systems. The structure of the pod must be able to
withstand all loads and vibrations, while also meeting all
design specifications as laid out by SpaceX.
12
17. 1.1 Overall Structure
• Full Size Pod
– Structure Mass: 3,700 lbm
– Width: 78 in
– 6061 Aluminum
– Fiberglass skin
17
• Structure Components
– Pressure Vessel
– Chassis
– Struts
732 in
Front
108 in
18. 1.2 Prime Structure-Pressure Vessel
• Lightweight, aircraft-like structure
• Rings and Stringers
• 10 gauge aluminum shell (0.1 in.)
• Margin of safety of 2.5
• Mass of 1,500 lbm
18
19. 1.3 Prime Structure-Chassis
19
Three Main Components
• Main Chassis Skid
• Struts
• Magnetic Supports
Magnet Module Section View
Struts
Magnetic
Supports Main
Chassis
Skid
20. 1.4 Structure for Aerodynamics
• Skin Fairing
– Lightweight fiberglass
– Minimizes friction and weight, maximizes stiffness
– Provides a path for air to travel around the pod
• Nose/Tail Cone
– Fiberglass skin, reinforced by
aluminum rings and stringers
20
Front
Rear
21. 1.5 Structure for Aerodynamics
21
*Simulated with interior tube
diameter of 16 feet
*Simulated with pod speed of 700 mph
16 ft diameter tube
23. 1.7 Structure Ingress/Egress
• Plug Door at Front of Pod
– Primary entry and exit
– Load bearing (aluminum frame)
– Metal Seal Energizer (MSE) configuration
• Emergency Exit built into primary
door
– Can be operated regardless of pressure
differential
23
25. 2.1 Vertical Support Alternatives
25
Concept Pros Cons
Electromagnetic Suspension
(EMS)
∙ Pluralization of function with
propulsion
∙ No added
mass/infrastructure
∙ Lower maintenance costs
∙ Complex feedback loops
required
∙ Stability
Air Bearings via Pressure
Vessel
∙ No need for compressor
∙ Lower power consumption
∙ Decreased performance as
tank is depleted
∙ Significant mass
Electrodynamic Suspension
(EDS)
∙ Stable equilibrium
∙ Pluralization of function with
propulsion
∙ Still in development
∙ Feasibility
Air Bearings via On-board
Compressor
∙ Lesser Kantrowitz effect
∙ Less storage needed
∙ Provides continuous source
of air
∙ Compression ratio not
attainable with current
technology
∙ Heavy
26. 1 2
3
4
2.2 Vertical Support Module Topology
• Electromagnetic Module
– 4 Modules Total
– 1 Pole pair Each
– Pole pairs coupled though
ferromagnetic back-iron
26
# Module Components
1 Pole Shoe
2 Pole Core
3 Back Iron (Yoke)
4 Aluminum Coil (MMF)
5 C-Beam Rail & Stator
Core
5
25.5 in
27. 2.4 Lateral Stability
27
• 20 E-shaped electromagnets utilized
• Mass: 1,175 lbm
• Electrical Requirements: 40 A current, 2.5 kW per magnet
2.61 in.
1.97 in.
0.7 Teslas < Saturation Limit
Lateral Stability MagnetFlux Density Graph
28. 2.5 Battery Systems for Magnets
28
• All batteries connected in series
• 200 cells per pack
• Each rack is installed on rails
• 30 battery packs on each side
• 12,000 total cells
5.5in.
31. 3.1 Propulsion Alternatives
Concept Pros Cons
Turbine
∙ Well-established
∙ Easy to control
∙ Low atmosphere conditions
∙ Exhaust in tube
Electric motor and wheels
∙ Well-established
∙ Easy to control
∙ Trouble reaching desired speed
∙ Feasibility
Steam Catapult
∙ No added mass on pod
∙ High initial acceleration
∙ Inability to maintain speed
∙ Feasibility
Rail Gun
∙ High initial acceleration
∙ No added mass on pod
∙ Significant energy requirements
∙ High temperature and low life
span of system
Magnetic Propulsion (LSM/LIM)
∙ Easy to control
∙ Effective over full speed range
∙ Can be used to brake
∙ Weight from magnets
31
The decision came down to the linear induction motor vs. the linear synchronous motor.
32. 3.2 Linear Induction Motor (LIM) vs. Linear
Synchronous Motor (LSM)
32
Both LIM and LSM were considered. After a formal down-selection process, the
LSM was selected for pod propulsion.
Higher Power Density
Speed is independent
of load
33. 3.3 DC Excited Linear Synchronous Motor
with Active Guideway
• Propulsion
– 3 Phase Power Channeled through
Stator Core Mounted on Underside of
Guideway
– Pod Travels at synchronous speed
created by stator flux
– Projected Cruising Speed = 700 mph
33
Underside of Stator
Rotor or “Mover”
36. 4.1 Normal Braking Operation
36
• Primary braking will be performed by using a negative sequence for the
three phase power of the stator
• Multi-tasking the propulsion system allows for mass and cost minimization
as well as design simplicity
• For mass, energy, and motor outputs, refer to the propulsion slides
37. 4.2 Emergency Friction Brakes
37
• Mass of 4 sleds = 1694 lbm
• Material: Aluminum, C/SiC, Teflon
• Wear thickness: t ~ 0.02 inches
• Maximum Temperature Change: ΔT = 500°F
• Stopping Distance: 10.7 miles
*Calculations done at 700 mph
* Dimensions in inches
* Dimensions in inches
39. 5.1 Inflatable Emergency Egress System
(IEES)
39
Inflatable Plugs
High Strength
Breakaway Tether
Breathable Environment
* Schematic not to scale
40. 5.2 IEES – Deployment: Tail Cone
(1) Storage Location and Accessibility
40
Plug is stowed within tail
cone, and hatch is opened.
(2) Deployment
Spring pusher plate forces
plug out of compartment and
into tube.
41. 5.3 IEES – Deployment: Tail Cone
• (3) Inflation
– Chemical Reaction is triggered, inflating plug
– Plug is tethered to chassis of pod
41
42. 5.4 IEES – Deployment: Nose Cone
• (1) Storage Location and Accessibility
– Plug directly mounted to rigid structure
– Nose cone tip decouples from structure
42
43. 5.5 IEES – Deployment: Nose Cone
• (2) Deployment
– Plug is sealed by pressure between nose cone
cage and hemisphere mounting rings.
43
Hemisphere
Ring
Fabric Plug
Rim
Cage Ring
F
44. 5.6 IEES – Fully Deployed
44
* Schematic not to scale
Breathable Environment
45. 5.7 IEES – Application as Emergency Brake
• “Low Pressure” Parachute
• Use Inflatable plug for friction
• Load limiting lanyard provides constant low force
application
45
* Schematic not to scale
53. Closing Remarks
• The Hyperloop Project statement was decomposed into necessary sub functions.
• The team designed the subsystems to best satisfy these sub functions.
• At each iterative step the subsystems were integrated into our final Hyperloop
System Design.
• In the remainder of the semester, we plan to continue optimizing the design further.
53
55. # Systems
1 Structure
2 Vertical Support
3 Propulsion
4 Braking
5 Safety - IEES
6 Sensors and Controls
1
5
55
System Design Overview
2,3,4
4
Air Bearing System MagLev System
3,4
2
57. 1.1 Structure Overview
• Comparison to Fall Semester
• Aerodynamics
• Pressure Vessel Redesign
• Internal Structure and Seating
• Pressure Vessel Support
• Chassis (Maglev and Air
Bearings)
• Ingress, Egress, Emergency
Exits
58. 1.2 Old vs. New Designs
• Aluminum main structure
• Fiberglass fairing
• Designed to be lightweight,
easily manufactured, and
inexpensive
• Total mass: 3700 lbm
• Carbon Fiber Epoxy skin, fairing,
chassis
• Aluminum rings and connectors
• Fairing is integrated into structure
• Maglev and Air Bearing compatible
• Designed to be ultra lightweight
• Total mass: 1500 lbm
59. Air Bearing New MaglevOld Maglev
1.3 Structural Design Changes
65. Pressure Vessel Interior Framework
• Built of carbon fiber tubes with aluminum joints
• Integrates floor and seat framing into one system
• Framework attaches to the pressure vessel rings
UPDATE WITH NEW FULL ASSEMBLY
66. Pressure Vessel Interior Framework
• Seat framework supports carbon fiber honeycomb floor
• Mass approximately 7.5 lbm per seat/floor unit
• Can withstand 10g deceleration
• Tube wall thickness can be changed to support heavier loads
68. Seat FEA Analysis
• Designed for 10G forward load
• Failure point: diagonal side member
• Failure mode: column buckling
69. 1.13 Chassis Redesign
• Maglev and Air Bearing designs
• Design considerations:
• Levitation system
• Pressure vessel weight
• Normal acceleration
• 3g deceleration
• Emergency braking
• Carbon fiber epoxy tubes and
connectors
• Improvements from Aluminum
• Weight reduction
• Increased stiffness
Maglev Chassis
Air Bearing Chassis
70. 1.14 Maglev Chassis
*Dimensions in inches
• Utilizes two C-channel rails
• Design Considerations:
• Mass
• Magnet supporting beams
• Stress distribution
• Storage
• Carbon fiber epoxy
• Mass: 300 lbm
• Battery storage
• Space for life support systems
3 in. Carbon Fiber square tubing
(.085 in. wall thickness)
113
18
71. 81
1.15 Air Bearing Chassis
*Dimensions in inches
• Utilizes two vertical rails
• Design Consideration:
• Weight
• Stress distribution
• Storage
• Mass: 225 lbm
• Similar carbon fiber structure
• Compressed air storage
• Up to six 1 ft. wide by 40 ft.
long tanks
• Uniform stress distribution
3 in. Carbon Fiber square tubing
(.085 in. wall thickness)
18
72. 1.16 Advanced Strut Design Overview
• The advanced strut design
supports the pressure vessel
• This design contains two CFRP
sheets pinned to Mg alloy struts
• The total mass, including both
sides, is 374.44 lbm
• Maximum allowed force due to
buckling is 2530 kips
Advanced
Strut
Design
Advanced
Strut
Design
73. 1.17 Composite Cross Section
• Composite cross section designed
to have high moment of inertia to
prevent buckling
• CFRP sheets are pinned to the Mg
alloy strut because CFRP can not
be attached using traditional
methods such as welding
• CFRP sheets are glued together
on the sides using epoxy
74. 1.18 Advanced Strut Assembly
• Ball and socket joints are used to
eliminate moment reactions at the
joint locations
• The socket contains two ball inputs to
save weight and reduce the number
of parts
• Contains 56 Mg alloy struts per side,
each forming 45o angles w.r.t the top
socket
112 Double Sided
Pins for Both
Sheets
57 (1 inch) Ball and
Socket Joints Per
Side
2 CFRP (486.5x11.75x
0.0625 inch) Sheets
75. *Strut Specifications
• Designed for:
– 3g max linear acceleration
– Safety factor of 2
• Strut Angles
– Phi=80°
– Theta=63°
• Carbon fiber tubes
– 64 cylindrical shells
– Outer radius of 1 in,
thickness of 0.0005 in
76. *Carbon Fiber Tube Analysis
• Margins of Safety (Distortion Energy)
– Maximum Stress: 2.45
– Buckling: 1.19
• Total Mass of Tubes (w/o Connectors)
– 0.55 lbm
• Failure Based on Yielding
77. *Adhesive Cylindrical Lap Connectors
• Internal and External Surfaces
• Epoxy Resin
• Prevents Failure on Tube Ends
• Bolted Connections to Chassis and Pod
• 6061-T6 Aluminium
• More Calculations Required
78. 1.22 Redesigned Primary Door
• Overall design largely unchanged
– Same sealing and opening method
• Composed of carbon fiber and aluminum honeycomb
• Mass reduced to 39 lbm
78
Door 95% Male
Height [in] 63 75
Projected Height [in] 63 67
Width [in] 36 24
63 in.
36 in.
80. 54 in.
36 in.
1.24 Redesigned Emergency Exit
• Two emergency exits
– One within main door at front of pod
– One at back of pod on opposite side of front exit
• Composed of same carbon epoxy honeycomb as pressure vessel
• Mass = 26 lbm
• Pressure differential exerts Fn of 3,750 lbf on each latch
• Bearings (µ = 0.0015) reduce total Ffr to 11 lbf
• Latches released when 15 lbf applied to 5 in. lever
• Hinged at bottom for controlled opening
– Doubles as ramp for easy exit of pod
80
90. 2.8 Pressure Regulators
• Regulators limited by
flow rate
• Flow rate depends on
pod weight
90
*regulator schematic for 18,000 lbm pod
Flow
Rate
Number of PR’s
Required Total
Mass
1310G
MR95
H
1098-
EGR
0.39
lbm/s
15 5 3 395 lbm
*based on pod mass of 18,000 lbm
91. 2.9 Wheel Contingency
• 8 wheels to support structural bending
• Protects skirt when idle, ensure mobility upon bearing
failure
91
Drag bar in
tension
93. 93
3.1 Lateral stability Magnets
Resize stability magnets using
new pod weight
- New mass of stability
system: 411 lbm
- 60% mass reduction
- 1.8 kW per magnet
- 112 lbf (500 N) per magnet
- 10 magnets on each side of
pod
- Serves as DC Excitation in
Air Bearings design
3.77in
1.57in 10.06in
102. 3.10 Magnetic Circuit
Reluctance of module 61.58 H-1 Module flux (f) 0.3895 T
Reluctance of air gap 3.38 MH-1 Air gap flux (g) 0.3571 T
Reluctance of single tooth 15.65 H-1 Leakage flux for air
gap (lg)
0.0036 T
Reluctance of stator core per
pole pitch
1.32 kH-1 Leakage flux for
module (lm)
0.0324 T
Reluctance of module per pole
pitch
2.50 kH-1 Flux linked with
stator winding
0.3535 T
Reluctance for magnet
leakage flux
0.95 MH-1
Reluctance of air gap leakage
flux
3.38 MH-1
104. 4.1 Normal Braking Operation
104
• Primary braking will be performed by using a negative sequence for the
three phase power of the stator
• Multi-tasking the propulsion system allows for mass and cost minimization
as well as design simplicity
• For mass, energy, and motor outputs, refer to the Propulsion section
105. 4.2 Emergency Friction Brakes – Placement
105
EMS Design
Air Bearing Design
•Can blow air over the
sleds to cool them
Sleds
Sleds
106. 4.3 Emergency Friction Brakes – Sled Design
• Sleds used in both designs (EMS and Air Bearings)
• Air channel for cooling using pressurized air
• Dimensions: 9.8 in. wide x 2.95 in. tall x 480 in. long
• Mass: 920 lbm
• Stopping distance: 10.3 mi. at max speed (700 mph)
106
C/SiC
Al
107. 4.4 Emergency Friction Brakes – Design Idea
• Spring-actuated pistons to increase stopping force
• Greatly increased heat generation
• Not used in final design
107
*All dimensions in Inches
108. 4.5 Inflatable Friction Plug Emergency Brake
• Use inflatable plug for friction
against tube
• Acts similar to a parachute,
but operates without air
resistance
• Load limiting lanyard
provides constant low force
application
108
A
A
Pod Velocity Constant Force
109. 4.6 Plug Brake with Circumferential Ribbing
• Slowing at 3 g's from 550 mph would
result in an average temperature rise
of roughly 400 °F in the plug fabric with
no ribbing
• C/SiC pads installed around the
circumference of the plug in the
contact region
– Better thermal properties
– Tougher material
– Higher coefficient of friction
– Allows for airflow convection
109
16 ft. Dia.
112. 5.2 Toroidal Inflatable Specs
• Interior circle of torus
mounts to pressure vessel
ring
• Smaller cross section on
bottom than top, in order to
conform with tube
• Mounted to pressure vessel
rings
112
17ft
6ft
3.5ft
7.5ft
113. 5.3 – IEES Operation and Evacuation Plan
1. Pod comes to halt, deflated
tori wrapped and strapped
around cones
1. Tori are inflated using Sodium
azide Reaction
1. Area surrounding pod is
pressurized with onboard air
tank.
1. Emergency exit doors open in
front and back
1. 28 Passengers exit pod into
pressurized region of tube and
move towards emergency
exits.
113
(t = 0s)
(t = 5s)
(t = 45s)
(t = 50s)
(t = 90s)
Velocity = 0 mph
Reaction triggered,
pressurization begins
115. 6.1.1 Center of Mass (COM) Dynamics
• Purpose: Examine passenger ride comfort
• Allows for coupling of the 4 levitation modules
• Determines legitimacy of not including suspension
115
116. 6.1.2 Extension to COM
116
● Full rotational dynamics are unnecessary and computationally expensive
● Small Angle Assumption and Gap width vs. Pod Kinematic Constraints
(Θ, Φ, & Ψ=0)
● COM dynamics can be estimated using one magnet (as done originally),
but more accurate through potential and kinetic energy averaging
● Unique seeds were used to create different input noise for each magnet
New Pod Dynamics
117. 6.1.3 COM Simulation Modification
117
Plant Modification
Function
Output
Individual Magnet Simulation
Unique Seeding
124. 6.2.1 Air Bearing System Characteristics
• System assumptions similar to electromagnets:
– Small angle assumption is still valid
– Only Degree of Freedom (DOF) is vertical motion
• Cushion Pressure: ~3200 Pa
• Environmental Pressure: 100 Pa
• Expected Hover Height : 1mm (English unit)
• Expected Mass Flow Rate: 0.195 kg/s
124
128. 6.2.5 Air Bearing Sensors
• Pressure transducers
– 0 to 2.5 psi range
– 0.08% accuracy
– Measure skirt and cushion pressure
• Distance Sensors
– New mounting fixtures away from ground
– Measure ~1mm gap height
128
129. Closing Remarks Slide***
• Wrap up Advanced Design
• Design Process
– Blank Sheet of Paper to Full Design
• Summary of Year in Review
– Teams of 4
– Two large teams of 16 and 25
– Final team of 41
– SpaceX Competition Design Weekend
– Trip to Doha, Qatar, and work with TAMUQ Hyperloop
team
– Final Design Package today
129
132. 2.3 Vertical Support Module Capabilities
• Electromagnetic Module
– Suspends Pod through
electromagnetic attractive force
– Max Suspension Force = 54,963 lbf
– Also provides the DC Excitation
necessary for propulsion
132
142. Supplemental Slide XX: Unhinged vs. Bottom
Hinged
142
Design Advantages Disadvantages
Unhinged • Lightweight design • Complex, heavy opening
mechanism
• Possible safety hazard from
uncontrolled door ejection
Bottom Hinged • Relatively controlled
opening motion
• Exit aid
• Simplified latch
mechanism possible
• Added weight from ramp
• Added weight from damper
(if included)
143. Supplemental Slide XX: Emergency Exit
Operation (Update after simplifying)
• Latch mechanism is double rack and a pinion
– Rotation in central gear produces linear motion in side latches
• Must overcome friction from pressure-induced normal force on latches
– Fn = 14,930 lbf
• Ball bearing bushings used in latch holders to reduce friction (µ = 0.0015)
– Ffr = 22.4 lbf
• 15 lbf applied to 7.5 in.
turnstile lever opens door
143
7.5 in.
15 lbf
