1

Team Hullabaloop

May 4, 2016

Hyperloop Pod

System Design Package

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

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

• David McDermott

Team Photo

4

BackgroundSpaceX design requirements:

– Hold 28 passengers

– Low pressure tube ~ 0.014 psi

– High Speed ~ 760 mph

• 30 - 35 minute trip (350 mi)

5

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

Videos

• https://youtu.be/f4EOIUN2HRs

(Hullabaloop Team)

• https://youtu.be/w5UWYO5tN6I (Texas

A&M Hyperloop)

7

8

9

Qatar Trip

10

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

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

Top Level Function Structure

13

Competition Weekend Design

14

# Systems

1 Structure

2 Vertical Support

3 Propulsion

4 Braking

5 Safety - IEES

6 Sensors and Controls

2

15

15

System Design Overview

2,3,46

732 inches

72 inch Dia.

1.0 Structure

16

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

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

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

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

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

22

1.6 Interior Structure

• Capacity: 28 seats,14 rows

• Rear facing, aircraft-like seats

• ½ inch honeycomb composite flooring

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

2.0 Electromagnetic Suspension (EMS)

24

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

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

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

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

5.5

in.

System

Power Required

(kW)

Vertical Support

Magnets 120

Lateral Stability

Magnets 23

Propulsion 4

Interior Systems 3

Total 150

2.6 Battery Power

29

• For 45 min trip – 110 kWh

• Batteries provide 132 kWh

3.0 Propulsion

30

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.

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

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”

3.4 Kinematic Characteristics

34

*Calculations based on 16’ diameter tube

4.0 Braking

35

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

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

5.0 Inflatable Emergency Egress System

38

5.1 Inflatable Emergency Egress System

(IEES)

39

Inflatable Plugs

High Strength

Breakaway TetherBreathable Environment

* Schematic not to scale

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.

5.3 IEES – Deployment: Tail Cone

• (3) Inflation

– Chemical Reaction is triggered, inflating plug

– Plug is tethered to chassis of pod

41

5.4 IEES – Deployment: Nose Cone

• (1) Storage Location and Accessibility

– Plug directly mounted to rigid structure

– Nose cone tip decouples from structure

42

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

5.6 IEES – Fully Deployed

44

* Schematic not to scale

Breathable Environment

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

6.0 Sensors and Controls

46

6.1 Data Acquisition Sensors and Processors

Bubble Number Device Quantity

1 Pitot Tube 1

2LS-S50ML Photo

Reflective Sensor6

3

MicroStrain 3DM-GX4-45

Inertial Measurement

Unit

2

3On-board processor

2

3National Instruments

Data Acquisition System2

4

Fargo Controls 18mm

Photoelectric Proximity

Sensor18

5 Hall Sensor 4

47

6.2 Sensor Placement Map

48

1

2

4

3

5

6.3 Vertical Support Dynamic Model

49

Vertical Support Magnet Model

Pod

Stator

6.4 Vertical Support: Linear Quadratic

Gaussian Control Simulation

50

Noise Generation

Plant

State Feedback Control

Kalman Filter

6.5 Vertical Support Controller

Simulation

51Gap Width Response

6.6 Vertical Support Controller

Simulation

52Gap Acceleration Response

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

Advanced Design

54

# Systems

1 Structure

2 Vertical Support

3 Propulsion

4 Braking

5 Safety - IEES

6 Sensors and Controls

15

55

System Design Overview

2,3,4

4

Air Bearing System MagLev System

3,4

2

1.0 Structure

56

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

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

Air Bearing New MaglevOld Maglev

1.3 Structural Design Changes

1.4 Aerodynamics

• Old Design– Projected area: 6900 in2

– 1400 lbm external fairing

– Overall structure mass: 3700 lbm

• New Design– Projected area: 6000 in2

– No external fairing

– Overall structure mass: 1200 lbm

60

Previous Design

Current Design

1.5 Aerodynamics

• Drag Force

– Previous Design: 27 lbf

– Current Design: 33 lbf

– Weight reduction justifies

increased dragPrevious Design Aerodynamics

Current Design Aerodynamics

1.6 Integration of Fairing

• Decreases mass by as

much as 750 lbm

• Includes both ends in

calculations

• Assumptions made for

ring

in both cases

1.7 Pressure vessel

63

1.8 Pressure vessel

• Honeycomb Sandwich Composite– Aluminum Honeycomb (0.65 in.)

– CFRP Skin (0.05 in.)

• Margin of Safety = 1.75

• Composite mass= 975 lbm

• Frame mass= 500 lbm

64

StressMinimum

Thickness (in.)

Hoop Stress 0.015 (CFRP)

Axial Stress 0.0075 (CFRP)

Shear Stress 0.0062 (CFRP)

Point Load Stress 0.25 (Al Core)

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

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

Seat Specifications

67

Seat FEA Analysis

• Designed for 10G forward load

• Failure point: diagonal side member

• Failure mode: column buckling

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

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

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

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

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

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

*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

*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

*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

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.

1.23 Primary Door Operation

79

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

1.25 Emergency Exit Operation

81

(Front View)

Exits Closed Exits Opened

2.0 Air Bearings

82

2.1 Air Bearing Concept

• Flexible skirt• Advantages

– Reduced complexity – Reduce weight– Cooling

83

2.2 Bearing on Pod

84

BearingTanks

Pressure

Vessel

Chassis

2.3 How it works

• Pressure and flow rate managed with regulators and controls

• Flexible material has inherent stability

85

2.4 Bearing Material

• Flexible, lightweight, low drag, thin (< 1.5 in), fully responsive

• Coated with blend of natural and synthetic rubber

86

2.5 Tanks

87

● 4 total tanks

● 0.27 in. thick CFRP with

aluminum lining

● 11.5 in. ID x 38 ft. long

● Internal pressure: 5000 psi

2.6 Manifold

88

● ¼ in. stainless steel tubing

○ 0.035 in. wall thickness

○ 5100 psi AWP

● 1 in. stainless steel tubing

○ 0.065 in. wall thickness

○ 2400 psi AWP

2.7 Pressure Regulators

• Recommended 3 Cuts

• 5000 - 500 - 15 - 1 psi

• 1301G HP Regulator– Max inlet: 6000 psi

– Outlet range: 200-500 psi

– 8 lbm

• MR95H– Max inlet: 1000 psi

– Max outlet: 450 psi

– 22 lbm

• 1098-EGR– Pilot-operated (Type 61L)

– Max inlet: 400 psi

– Outlet: 0.25-2 psi

– 55 lbm

89

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

Mass1310G

MR95

H

1098-

EGR

0.39

lbm/s15 5 3 395 lbm

*based on pod mass of 18,000 lbm

2.9 Wheel Contingency

• 8 wheels to support structural bending• Protects skirt when idle, ensure mobility upon bearing

failure

91

Drag bar in

tension

3.0 Magnets

92

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

3.2 Banking

94

95

3.3 Levitation Magnets

Units?

96

3.4 ANSYS

3.5 Updated Dimensions

QuantityOriginal Values Updated Values

(mm) (in.) (mm) (in.)

Pole Pitch 626 25 626 25

Pole Shoe Length 417 16 417 16

Module Width 376 15 376 15

Back Iron Length 1630 64 1626 64

Cylinder Core Radius 76 3.0 40 1.57

Cylinder Core Height 152 6.0 80 3.2

Back Iron Depth 112 4.4 25 1.0

Pole Shoe Depth 50 2.0 25 1.0

Module Weight 622 kg 1371 lbm 154 kg 340 lbm

System Weight 2488 kg 5485 lbm 615 kg 1356 lbm

75% decrease in system weight

3.6 Batteries

System Power Required (kW)

Lateral Stability Magnets 18

Levitation Magnets 5

Interior Systems 3

Total 26

*3.7 Displacement FEA: Normal

Operation [Do we want these]

(Structure?)

*3.8 Displacement: 3g

Acceleration(Structure?)

101

3.9 Magnetic Circuit

DC Excitation (On

Pod)

Air gap

Stator (On

Guideway)

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

4.0 Braking

103

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

4.2 Emergency Friction Brakes – Placement

105

EMS Design

Air Bearing Design

•Can blow air over the

sleds to cool them

Sleds

Sleds

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

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

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

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.

5.0 Inflatable Emergency Egress System

110

5.1 Inflatable Emergency Egress System

(IEES)

111

Inflatable Plugs

Breathable Environment

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

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

6.1.0 Electromagnetic Dynamics

114

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

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

6.1.3 COM Simulation Modification

117

Plant Modification

Function

Output

Individual Magnet Simulation

Unique Seeding

6.1.4 COM Simulation Modification Contd.

118

COM Acceleration

COM Position

6.1.5 COM Position

119

6.1.6 COM Filtered Position

120

6.1.7 COM Acceleration

121

6.1.8 COM Filtered Acceleration

122

6.2.0 Air Bearings Controls

123

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

6.2.2 Defining Exit Flow

•

125

6.2.3 Air Bearing Equations

•

126

6.2.4 Air Bearing Dynamic Solution

127

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

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

QUESTIONS?

130

Friction Brake Specifications

131

C/SiC Al 6061 Teflon

Friction Coeff. w/ steel

(kinetic)0.29 --- 0.05

Wear Factor [Pa-1] 1.0*10-12 --- 5.04*10-4

Density [kg/m3] 2450 2700 2160

Hardness 25 GPa 1.0 GPa 50 Shore D

Specific Heat Capacity

[kJ/kgK]0.80 0.90 1.01

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

NCR18650 Specs

http://industrial.panasonic.com/lecs/www-data/pdf2/ACA4000/ACA4000CE417.pdf

Diagrams● 30 battery packs each side

● Connected in series

● 200 cells per pack

Battery Pack

+

-

-

200

cells

200

cells

200

cells... 200

cells

60

Packs+

+ -

Battery, DC-DC Converter, Battery Management System (BMS), and Battery Cooling System housed in 2 enclosures along length of pod

1.5 Structure for Aerodynamics

Tube

Diameter (ft)Drag Coefficient

Drag

Force (lbf)

12 2.19 125.9

16 0.89 50.9

20 0.61 35.1

136

SpeedDrag

Force (lbf)

Maximum Air

Velocity (mph)

500 27.8 704.4

550 33.2 769.1

600 38.7 838.9

650 44.8 914.2

700 50.9 974.9

*Interior tube diameter of 16 feet

IEES Extra Slides

137

Flow Rate Calculations

Abearing

Blue is

pbearing

Back Up Pictures

Chassis Weight/Strength Comparison

(Backup)

140

13 lb CF truss supports 3000 lbs

Carbon Fiber Epoxy Specs (Backup)

• The CF tubes of choice are:

• 50% VF CF Epoxy

• [±45,0,90]s

• Tensile, Compressive Strength: 320,270 KSI

141

Loading conditions:

10,000 lb PV

3g deceleration

1g turn

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)

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