University of Colorado at Boulder
Aerospace Engineering
Fall 2003
Critical Design Review
Remote Aquatic Vehicle (RAV)
Matthew Allgeier
Kevin DiFalco
Daniel Hunt
Derrick Maestas
Steve Nauman
Jaclyn Poon
Aaron Shileikis
Presentation Outline
RFA’s and Changes since PDR
System Architecture
Subsystems Design Elements




Analysis
Mechanical Design
Electrical Design
Subsystems Testing & Verification
Integration Plan
Verification & Test Plan
Project Management Plan
03 Dec 03
RAV CDR Presentation
2
RFA’s
Request for Action (RFA)
Double Pressure Hull Design
Required Range &
Mission Goal Clarification
Top Speed Test Location
Detailed Monetary Budget
Battery Specifications
03 Dec 03
Requested By
Reply
Dr. Maute
Manufacturing Limits &
Limited Internal Volume
Dr. Lawrence
Clarified Mission Goals & Range
addressed in Objectives Overview &
Test Section
Dr.Peterson
Lowered Top Speed and Determined
Location
Dr.Peterson
Detailed Budget addressed in Project
Management Plan
Trudy Schwartz
Subsystem's Battery Specifications
addressed in Electrical Design
RAV CDR Presentation
3
Overview of Objectives
Mission Statement

The main objective for team RAV is to conceive, design, fabricate, integrate,
verify and test a versatile proof of concept for a remotely controlled aquatic
vehicle capable of both high speed, long range and low speed, short range
maneuverability in challenging aquatic environments.
Objectives Summary

3-axis High Speed Manueverability
Low Drag, High Speed & Long Range

3-axis Low Speed Manueverability
Active Buoyancy
Yaw Rotation and Strafing

Small Size
Navigation of Challenging Obstacles
Ease of Deployment Logistics
Ease of Manufacturing


Specifications Derived from Facility, Monetary & Volume
Limitations and Subsystems Requirements
Detailed Final Objective in Verification & Testing Section
Test Illustration at Carlson Pool
03 Dec 03
RAV CDR Presentation
4
Overview of Requirements
Structure

Pressure rated to 44 psi (20m Depth)
Buoyancy



Functional to 66 ft. (20 m)
RC Controllable to 2ft* Depth
Ascent/Descent Rate of 0.5 ft/sec*
Propulsion



5 knots
Reversible
Variable speed
Low Speed Maneuvering (LSM)


Rotation Rate of 0.33 rev/min*
Minimal Drag during High Speed Maneuvering
*changed from PDR
03 Dec 03
RAV CDR Presentation
5
Overview of Mechanical Design
03 Dec 03
RAV CDR Presentation
6
Overview of Electrical Design
Battery (24V)
Speed Control
Motor
Servos
Receiver
Battery
Receiver
Battery(12V)
Battery(12V)
LSM Control
Buoyancy
Control
LSM Jets
Buoyancy
Motor
Pressure
Transducer
Anemometer
HOBO
Subsystems
03 Dec 03
RAV CDR Presentation
7
Subsystems Design Elements
Hydrodynamics & Structure
Buoyancy
Propulsion
LSM
Communication
03 Dec 03
RAV CDR Presentation
8
Hydrodynamic & Structural Analyses
Fluid Mechanics
Subsystem Design
5 Knot Speed Goal
Minimize Drag
20 Meter Depth Goal
(45 psi)
Aluminum Hull
Lower Cost &
Ease of Procurement
Testable Sealing
Machine
In-House
Hyperbaric Chamber
See additional chart
CSU Chamber
Pressure
Transducer &
HOBO
Stress Analysis
6" Outer
Diameter
03 Dec 03
RAV CDR Presentation
Acrylic Nose
Cone
Aluminum Tail
Section
9
Drag Reduction Flowchart
Goal:
Minimize Drag
Decrease
Outer Diameter
HydroBuff Shape
Myring
Hull Contour
6" Outer Diameter
Decrease # of
Control Surfaces
1m
Overall Length
Aluminum Hull
due to Availability
High Speed
Trimmability
Nose Cone and
Tail Piece Shapes
Trim Vertically
if CB is off
Aluminum Airfoils
Trim Laterally
if CG is not on
centerline
NACA 0012
3" X 3"
Alreco Aluminum
Sealing
Servo Specs
From Propulsion
Use of Shroud
FINAL DRAG
COMPUTATION
03 Dec 03
RAV CDR Presentation
10
Hull Design
Myring Hull Contour Design [H1]
3 compartments:



Nosecone
Mid-section
Tailpiece
Max outer diameter ≤ 6 in.

Tailpiece Machining Limitation
Myring Hull Contour [H1]
Aluminum 6061 Mid Section

Availability, Machinability, Cost &
Strength
Mid-section


24 in. long x 1/8 in. thick
Maximum Internal Volume
Mid-Section Passes Structural
Compression Test
03 Dec 03
RAV CDR Presentation
RAV Design
11
Nose Cone & Tailpiece Design
RAV Nose Cone
03 Dec 03
Nose Cone & Tailpiece designed
using Myring Hull Contour Shape

Nosecone: 6 in. long

Tailpiece: 12 in. long
Nose Cone constructed of acrylic

Machine Shop Surplus of
acrylic

Future Camera Use
Decreased Outer Diameter ≤ 6 in.

Tailpiece machinable “inhouse”
Aluminum 6061 Tailpiece

Dissipate Heat from Motor
Final Total Drag

16.1 N at 5 knots

Antenna deployed at 6 in.
RAV CDR Presentation
12
Control Surface Design
Control Surfaces for Trimming


Dive Planes size determined by
Force difference between CB &
CG
Rudder size determined by force
from CG displacement from
centerline
4 Uniform Control Surfaces


Identical Design due to Horizontal
and Vertical Trim Requirements
Manufacturing Ease
4 Individual Servo’s


Motor Interference & Accessibility
Future Roll Control
Ideal Airfoil



03 Dec 03
Drag Polar Equation
Short Chord
Long Span
RAV Tail Piece & Control Surfaces
RAV CDR Presentation
13
Control Surface Sizing Conclusions
Selected NACA 0012 airfoil



Chord: 3 in.
Span: 3 in. long
1/8 in. servo shaft
Control surfaces & servo shaft

Aluminum - excellent strength to weight ratios.
Servo selection



03 Dec 03
15 deg. Control Surface deflection in 0.5 sec
Torque required 20.95 oz-in
Rated to 44.0 oz-in
RAV CDR Presentation
14
Control Surface Sealing Design
Withstand Pressure = 45.0 psi
Dynamic Seals

Low Friction Servo Movement
SCLS Brass Linkage Seal


Small 0.39 in. x 0.59 in. length
Contains an O-ring to prevent
water seepage
Seal will be pressed into tail
section and sealed with epoxy to
ensure no pressure leakage
1/8 in. diameter stainless steel
shaft will pass from servo to
control surface


Coupler will be used to attach
servo to shaft
Pins will be used to attach shaft
to control surface
03 Dec 03
RAV CDR Presentation
Control Surface Sealing Design
15
Structural Verification and Test Plan
Pressure/Sealing Verification
Description:
Verify entire assembly can withstand pressures of ~45psi (20m depth) without leaking using a
hyperbaric chamber. Accomplished by measuring pressure change inside.
Location: CSU hyperbaric chamber

Written confirmation obtained from Dr. Alan Tucker
Method and Measurements:

Increase pressure in hyperbaric chamber

Record pressure change inside hull

Test will be run at 45 psi for 30 minutes to correspond to the maximum amount of time the
sub will be in the water for the Final Full-Systems Integrated Test.

Tests indicating pressure changes ≤ 0.2 psi will be considered a success

If failure occurs at ~45 psi it will be run again at 20 psi to ensure no leakage during pool tests
Analysis:

Pressure vs. Time inside and outside hull

Any pressure change greater than 0.2 psi indicates leakage
Sensors: PX236 Pressure Transducer (Omega)

Range: 0 – 60 psi

Bandwidth: 2 Hz

Resolution: 0.1 psi

Accuracy: +/- 1.5%
03 Dec 03
RAV CDR Presentation
16
Buoyancy Analysis
Buoyancy
Subsystem Design
Inputs:
Overall Weight &
Volume
35 lbs
1034 cu3
Ascent/Decent Rate
0.5 ft/s
Operational Depth
20 m
System Volume
500 mL
Mass Flow Rate
required Mdot = 1.57 kg/s
@max rpm 11.64 kg/s
Pressure Force on
Piston @20 m
139 lbf
Cylinder Length
5 in
Inner Diameter
2 in
Overall Size
8.5" x 2.25"
03 Dec 03
Motor Selection
Small Johnson Motor
Stall Torque = 78.7 oz-in
Force Produced on Piston Head = 141 lbf
RAV CDR Presentation
17
Buoyancy Mechanical Design
Johnson Electric Motor (12V)


High rpm (16,000 rpm@12V)
Lightweight (7.50 oz per motor)
Alexander Engel Gear Set

Proven for piston systems
Threaded Piston Rod

6 mm
Piston Head


Aluminum
Machined in-house
Cylinder



Aluminum
Machined in-house
ID x OD x thickness:
2” x 2.25” x 0.125”
Batteries




4 DuraTrax Receiver NiCd Flat Pack 6 Volt
2200mAh (600mAh required per motor)
Length x Width x Height:
3-1/4“ x 1-3/4“ x 5/8"
Weight: 4.8 oz
Sealing


Precision Associates Inc.
Piston Head Seal
75-1.840

End Cap Seal
25-237
03 Dec 03
1.84” ID x 0.075” C/S x 2.0” OD
Buoyancy Tanks
0.237” ID x 0.025” C/S x .287” OD
RAV CDR Presentation
18
Buoyancy Electrical Design
Ballast Tank switch (BTS-II)
 Proven system for remote
submarines
 Electronic (no servos)
 Connects directly to
Receiver
Stop-full micro switch
Stop-empty micro switch
Trim switch
Buoyancy Electrical Schematic
03 Dec 03
RAV CDR Presentation
19
Buoyancy Verification & Test Plan
Static Motor Strength Test (Feb 7th)
Verify System Produces force to operate at a depth of 20m

Horizontal Load Cell
Resolution: 1 lb
Range: 50 lb – 400 lb
Accuracy: +/- 1 lb


Expected Results: 141 lb force
Requirements: 140 lb force
Buoyancy Subsystem Test (April 5th)
Verify descent and ascent rate

Antenna Marking w/ Stopwatch
Range: 0 – 6 ft
Resolution: 0.5 ft


[B1]
Expected Results: 3.0 ft/sec
Minimum Requirement: 0.5 ft/sec
Overall System Test (April 12th)
Verify system remains neutrally buoyant at given depth

PX236 Pressure Transducer
Range: 0 – 60 psi
Bandwidth: 2 Hz
Resolution: 0.1 psi
Accuracy: +/- 1.5%


03 Dec 03
Expected Results: 3.0 ft/sec with neutral buoyancy (< 0.2 psi change)
Minimum Requirement: 0.5 ft/sec with 1 minute neutral buoyancy
RAV CDR Presentation
20
Propulsion Analysis
Propulsion
Design
Motor Selection
BN28-36AF-01LH
210-262 W
Speed
Requirement
V = 5 knots
Controller
BDO-Q2-50-18
Required Amps
9A
Operational
Voltage
24 V
Required Duration
90 sec/test
1.2 V/cell
Safety Factor of 1.5
V = 7.5 knots
Drag
33 N
Pitch
6 inches
RPM
1576
Number of Tests
10
Power = D * V
Efficiency Motor
0.80
System
Component
Inefficiencies
Required mAh
2200 mAh
Efficiency Propeller
0.85
2600 mAh/cell
Efficiency Battery
0.90
System Power
Out Required
187 W
03 Dec 03
Battery Type
NiMH 2600 mAh
20 Cells
RAV CDR Presentation
21
Propulsion Mechanical Design






Major Components
Motor
BN28-36AF-01LH
Dimensions

Diameter = 2.25 inch

Length = 3.6 inch
Weigh: 46 oz
Controller
BDO-Q2-50-18
Dimensions

L = 6.69 inch

W = 3.54 inch

H = 1.73 inch
Weight: 13.76 oz
NiMH Batteries
20 Cells
1.2 V/cell
2600 mAh
Shaft
Hardened steel
Dictated by rotary shaft seal
requirements
Propeller
5.1 inch diameter
6.0 inch pitch
Shroud (specs)
Max outer diameter: 5.5 inches
Min outer diameter: 5.22 inches
Max inner diameter: 5.3 inches
Min inner diameter: 4.62 inches
Complex contour
03 Dec 03




RAV CDR Presentation
Mounting, accessories
Mounting
Motor to tail
Shroud to tail
Controller and batteries
Bearing
Ball bearing, double
shielded
Outer diameter: 5/8 inch
Inner diameter: 1/4 inch
2nd point of contact for
stability

Rated to 52,300
RPM
Bal Rotary Shaft Seal
71x model

60 psi

12,030 RPM
Splined shaft
Simplify assembly
22
Propulsion Electrical Design
Closed loop feedback system
BDO-Q2-50-18
Input
Transducer
v
Input
Potentiometer
BN28-36AF-01LH
Controller
r
volts
e
+
-
volts
Servo
Amplifier
Plant
m
Load
c
Servomotor
volts
Propeller
radians
Feedback
Elements
b
volts
Encoder
03 Dec 03
RAV CDR Presentation
23
Propulsion Velocity Test
9.14 m
CU Carlson Pool

Diagonal will be used
Safety Net
Progressive testing


Trim
Increasingly faster
< 20 m to accelerate to 5 knots, 2.75 m/s

Required acceleration: 0.134 m/s2
Sensors: Extech Mini-Anemometer




Range: 0.5 - 54.3 knots
Bandwidth: 3 Hz
Resolution: 0.3 knots
Accuracy: +/-(3% rdg+0.6 knots)
Data Collected


22.86 m
24.62 m
Distance vs. time
Velocity vs. time
Controlled Variables

Input voltage
Pool Testing Diagram
03 Dec 03
RAV CDR Presentation
24
LSM Analysis
LSM Subsystem
Design
System design
4 synthetic vortex jets actuated
by solenoids
Design Requirements
1/3 rpm
Drag Analysis /
Modeling Equation
Improve Design

Attach Film
to Return Stroke
Placement / Moment Arm
Sealing
Verify Equation with
4" Model Sub Testing
Decrease Size of
Solenoid Housing
Accurate Modeling
Equation for Prediction
Air Bubble Escape
Solenoid Selection
to Meet Moment
Design Mechanical System Volume
(Mount/cavity, housing)
Choose Exit Hole
Diameter
Optimize
Choose Frequency
Final Design
Test & Verify
8 jet configuration as
alternative
Aluminum mount and solenoid
housing
Permanently attached mount
Detachable housing
Latex diaphragm
O-ring seals
Circuit for control
12V NiMH Batteries
Integrate and Test
03 Dec 03
RAV CDR Presentation
25
LSM Drag Model
Cd vs. Re for a Cylinder
6
4
3
2
1
0
500
1000
1500
Reynolds Number
2000
2500
Cd and Velocity from Center (0) to Edge of Cylinder
6
Cd
Velocity
5
Coef. of Drag
Drag model for 4” diameter sub with 7”
moment arm to rotate 2/3 rpm
Required Thrust = 0.0321 N
Required Moment = 0.5311 N*cm
4” sub test results:
Exp Moment = 0.4896 N*cm
Error = 7.8 %
Coef of Drag
5
4
3
2
1
0
0
2
4
6
8
Length(inches)
10
12
14
[LSM1]
Drag model for 6” diameter sub with 9”
moment arm to rotate 2/3 rpm (SF2)
Required Thrust = 0.2952 N
Required Moment = 5 N*cm
-3
8
Moment from Center (0) to Edge of Cylinder
x 10
7
6
Drag model for 6” diameter sub with 9”
moment arm to rotate 1/3 rpm
Required Thrust = 0.0841 N
Required Moment = 1.523 N*cm
03 Dec 03
RAV CDR Presentation
Moment (N*cm)
5
4
3
2
1
0
0
2
4
6
8
Length(inches)
10
12
14
26
LSM Analysis
D (Exit Diameter)
Jet theory


L/D=4
Displaced volume (V1) = Exit
volume (V2)
Thrust provided by jet
Required moment = 5 N*cm /
jet
Moment vs. Frequency for
various exit diameters
Requirements for 0.6” exit
diameter to rotate 2/3 rpm:


Minimum frequency of 32Hz
Stroke length of 0.38”
L/D=4
V2
L
V1
Thrusting Moment vs. Frequency
9
Exit
Exit
Exit
Exit
Diameter =
Diameter =
Diameter =
Diameter =
0.5 in
0.55 in
0.6 in
0.65 in
8
7
Moment (N*cm)

6
5
4
3
2
1
0
5
03 Dec 03
RAV CDR Presentation
10
15
20
25
30
Frequency (Hz)
35
40
45
50
27
LSM Solenoid Selection
Soft-Shift Solenoid


Slow, smooth motion with
high starting force
Return spring available
Solenoid selection based
on:



Size: 1.875” x 1.935”
Stroke: 0.400 ± 0.030”
Typical frequency at 50%
duty cycle = 35 Hz
Stroke length deteriorates
as frequency increases
[LSM2]
03 Dec 03
RAV CDR Presentation
28
LSM Mechanical Design
Solenoid

Spring loaded, Soft Shift

12V, 24W at 50% duty cycle

Max frequency of 58Hz

.44 lbs
Housing

Aluminum or PVC

0.35 lbs
Plungers

2 mm thick
Mount

Aluminum (Welded to Hull)

0.27 lbs
Sealing

O-rings (not shown)
Overall Weight ~1.06 lbs (excluding
control circuit)
Final design pending (Exit Diameter)
based on testing and optimization
03 Dec 03
Solenoid
Housing
Plunger
Mount
RAV CDR Presentation
LSM Exploded View
29
LSM Electrical Design
Control


Receiver
Electronic RC switch
Oscillator Circuit
Power


RSGEX RC
Switch
Oscillator Circuit
12V at 1500 mAh/jet
NiMH batteries
Left Turning Jets
Battery (12V)
Oscillator Circuit
Right Turning Jets
+12V
RA
1k
1 Gnd555Vcc 8
2 Trg
Dis 7
3 Out
Thr 6
4 Rst
Ctl 5
C1
.01uF
+
+
RB
20k
CT
[LSM3] RSGEX RC Switch
Oscillator Circuit
03 Dec 03
RAV CDR Presentation
30
LSM Verification and Test Plan
Spin Rate Verification an Optimization
Description:
Verify theoretical drag model with 4” sub.
Using PVC model of RAV, different exit diameters and frequencies will be input,
while the resulting rotational speed will be measured.
Optimal exit diameter and frequency will be verified for final design.
Location:

CU Carlson Pool
Measurements and method:

Visually record and determine rotation rate
Analysis:


Plot rotational speed vs. frequency and exit diameter
Choose frequency and exit diameter which provide optimal thrust if different than
theoretical model
Expectations:


Jets will be optimal for an exit diameter of 0.6”
Minimal frequency of actuation at 32 Hz
Sensors:

03 Dec 03
Digital camcorder and stop watch
RAV CDR Presentation
31
LSM Verification & Test Plan
LSM Test Matrix
Controlled Variables:


Exit diameter
Frequency
Resultants:

Moment generated by
jets
Predictions:


Optimal exit diameter of
0.6”
Minimum frequency of
32 Hz
03 Dec 03
Test Frequency (Hz) Diameter (in)
1.1
10
0.5
1.2
15
0.5
1.3
20
0.5
1.4
25
0.5
1.5
30
0.5
1.6
35
0.5
2.1
10
0.55
2.2
15
0.55
2.3
20
0.55
2.4
25
0.55
2.5
30
0.55
2.6
35
0.55
3.1
10
0.6
3.2
15
0.6
3.3
20
0.6
3.4
25
0.6
3.5
30
0.6
3.6
35
0.6
4.1
10
0.65
4.2
15
0.65
4.3
20
0.65
4.4
25
0.65
4.5
30
0.65
4.6
35
0.65
RAV CDR Presentation
Expected Moment (N*cm)
0.165
0.372
0.661
1.033
1.488
2.025
0.293
0.659
1.172
1.831
2.636
3.588
0.494
1.111
1.975
3.086
4.443
6.048
0.259
0.582
1.034
1.616
2.327
3.167
Resulted Moment (N*cm)
32
Communication Analysis
RC controller
Power out ¾ W
Frequency
Selection
Attenuation of
Air
Antennae
Design
Refraction Index
Antennae Drag
Attenuation of
Water
Structural
Analysis
Power Gain
Reciever
Range
03 Dec 03
RAV CDR Presentation
33
Communication Design
Futaba 8UAPS/8UAFS and matching FP-R148DP Receiver (FM/PCM 1024)





Free Loan from Aerobotics Research Laboratory – Budget Constraints
8 Channels Available, RAV requires 7
0.75 W output
Receiver Power Gain Unknown
72.330 MHz, ¼ wavelength whip antenna = 3.23 ft. long
Signal Loss at 72.330 MHz


Refraction Loss = 53.00 dB
Attenuation of Chlorinated Water = ~300 dB/m
Conductivity varies with Chlorine Concentration (Avg Value = 200 µMhos/cm)
Antenna Design


¼ wavelength vertical antenna
Fiberglass Antenna Mast = 2ft. X 1/8 in.
Static Seal
Antenna Rise above Surface to avoid Losses
Run Propulsion Subsystems Test 6 in. below surface
Run to 75% Underwater Fail-Safe Depth for Full-Systems Integrated Test (if Tested)

Antenna Drag
14.41 N at 7.5 knots
6.40 N at 5.0 knots


Antenna Bending Moment
Conclusion
R/C not ideal for actual end goal – sufficient for Proof of Concept
03 Dec 03
RAV CDR Presentation
34
Communication Test Plan
Range Test

Move away from RAV until Fail Safe Initiates
Distance Step Function

Stretch Goal - Repeat with RAV Underwater
Quantify Receiver Power Gain
Quantify Antenna Design Parameters
03 Dec 03
RAV CDR Presentation
35
Data Acquisition
HOBO H8 4-Channel data logger



32K
External Input Channel Measurement Range:
0-2.5 DC Volts
External Input Channel Accuracy: ±10 mV
±3% of reading
Boxcar software for analysis
03 Dec 03
RAV CDR Presentation
36
Integration Plan
Drawing Tree
Purchased & Fabricated Parts
Assembly Flow Diagram

Order in which parts go together
Functional Test Plan (Subsystems Test Plans!!)


Test Parts
Test Assemblies
Identify Critical Path Elements





LSM Testing
Propulsion Ordering
Nosecone & Tailpiece Manufacturing
Facility Access
Hyperbaric Testing
Leak Testing

03 Dec 03
Buoyancy Static Test
RAV CDR Presentation
37
Drawing Tree - Sample
03 Dec 03
RAV CDR Presentation
38
Assembly Flow Diagram
Buoyancy
Tail
Buoyancy
Buoyancy
Tail
LSM Testing
LSM Testing
Buoyancy
Tail
Buoyancy
Buoyancy
Tail
LSM Testing
LSM Testing
Buoy Testing
Tail
Control Seals
Control Seals
Tail
LSM Manu
LSM Manu
Buoy Testing
Tail
Control Seals
Control Seals
Tail
LSM Manu
LSM Manu
Hull Manu
Main Flange /
Seals
Control Seals
Control Seals
Motor Seal &
Shaft
LSM Manu
LSM Manu
Hull / Buoy
Main Flange /
Seals
Payload Tray
Antenna
Motor Seal &
Shaft
LSM Manu
LSM Circuit
Hull / Buoy
Main Flange /
Seals
Payload Tray
Antenna
Motor Seal &
Shaft
LSM Manu
LSM Circuit
Nose
Payload Tray
Nose
Shroud
Integration
Integration
Integration
Integration
Integration
Integration
Integration
03 Dec 03
RAV CDR Presentation
39
Verification and Test Plan
Full Integration Test Plan Description
At point A, dive to depth of 2.5 ft (0.5 ft/sec)
Remain Buoyant for 2 min
Accelerate to 3 knots and stop at point B
Rotate counterclockwise 90° (45 sec)
Accelerate to 2 knots and stop at point C
Rotate clockwise 270° (2.25 min)
Arrive at point D by maneuvering around
obstacles using Buoyancy and LSM
Rotate counterclockwise 90° (45 sec)
Return to point A and surface using buoyancy
Repeat Testing
Test Time = 10 min/Lap
Location
CU Carlson Pool
03 Dec 03
RAV CDR Presentation
40
Verification & Test Plan
Expectations:

All subsystems tests will be verified on fully integrated
Sub
Top speed of 5 knots
Demonstrate active buoyancy
Rotational speed of 1/3 rpm
Sensors

Depth (Active Buoyancy)
PX236 pressure transducer

Speed
Extech mini-anemometer

Rotational Speed
Digital camcorder and stopwatch
03 Dec 03
RAV CDR Presentation
41
Project Management Plan
Organizational Responsibilities
Work Breakdown Structure
Schedule
Budget
Specialized Facilities & Resources
03 Dec 03
RAV CDR Presentation
42
Organization Chart
RAV Team
Advisor
Dr. Kamran Mohseni
Advisor
Dr. Scott Palo
Systems Engineer
Steve Nauman
Safety Engineer
Dan Hunt
Structures Group
Webpage Manager
Kevin DiFalco
Electronics Group
External Structure &
Fluid Mechanics
Matt Allgeier
Internal Structure &
Buoyancy
Dan hunt
03 Dec 03
Project Manager
Aaron Shileikis
Chief Financial Officer
Jaclyn Poon
Controls Group
Communications
Aaron Shileikis
Low Speed Maneuverability
Jaclyn Poon
Data Acquistion &
Instrumentation
Derrick Maestas
Propulsion
Kevin DiFalco
RAV CDR Presentation
43
Work Breakdown Structure
RAV Team
1.0 Project
Management
2.0 Systems
Engineering
3.0 Design
4.0 Fabrication
5.0 Integration
6.0 Verification
& Testing
7.0 Technical
Report
1.1 Organization
& Division of Labor
2.1 Project Objectives
3.1 Fluid Mechanics
& External Structure
4.1 External Structure
5.1 Sub-Assemblies
6.1 Data Acquisition
& Instrumentation
Testing
7.1 PDD
1.2 Work Breakdown
Structure
2.2 Design Integration
3.2 Buoyancy
4.2 Buoyancy
Subsystem
5.2 Nose
6.2 Communications
Testing
7.2 PDR
1.3 Schedule
2.3 CAD Drawings
3.3 Communications
4.3 Propulsion
Subsystem
5.3 Tail
6.3 Hyperbaric Chamber
& Leak Testing
7.3 CDR
1.4 Task Management
2.4 Internal
Configuration
3.4 Data Acquisition
& Instrumentation
4.4 LSM Subsystem
5.4 Hull
6.4 Buoyancy Testing
1.5 Budget
2.5 External
Configuration
3.5 Low Speed
Maneuverability
6.5 Propulsion Testing
1.6 Specialized
Facilities & Resources
2.6 Mass & Power
Budget
3.6 Propulsion
6.6 LSM Testing
6.7 Full Systems
Testing
1.7 Information Nodes
03 Dec 03
7.4 Final Report
RAV CDR Presentation
44
MS Project Schedule
03 Dec 03
RAV CDR Presentation
45
Task List - Sample
LSM subsystem task list
03 Dec 03
RAV CDR Presentation
46
Manufacturing & Integration
Time Estimates
Section
Time (Hours)
Nose
30.0
Mid-Section
36.5
Tail
86.0
Control Surfaces
41.0
Buoyancy
45.0
LSM
96.0
Electronics
30.0
Integration
30.0
TOTAL
394.5
TOTAL * 2
789.0
Weeks
10.0
Students
7.0
Hours/Student/Week
03 Dec 03
12.0
Total Hours Available
840.0
Margin
-51.0
RAV CDR Presentation
47
Budget
Budget Summary
Structure
$425.00
Buoyancy
$532.73
Communication
$149.38
Data Acquisition
$290.00
Propulsion
$1,149.35
LSM
$935.00
Accessories
$45.00
Support Equipment
$179.99
Testing Facilities
$435.00
Parts Total
$4,141.45
Shipping (5% Parts)
$207.07
Grand Total
$4,348.52
Available
$4,950.00
Goal 90%
$4,455.00
Margin (Grant Total - 90% Goal)
03 Dec 03
RAV CDR Presentation
-$106.48
48
Specialized Facilities & Resources
CSU Hyperbaric Chamber



Dr. Alan Tucker (access granted in writing)
150 ft. x 10 ft.
67 psi
CU Carlson Pool


John Meyer (access granted in writing)
25m x 12m x 1m
Aerobotics Laboratory

Cory Dixon (access granted in writing)
Aerospace Engineering Department & ITLL


03 Dec 03
Walt Lund, Trudy Schwartz, Matt Rhode & Bill Ingino
Testing Support Equipment
RAV CDR Presentation
49
References
Fluid Mechanics

[1] Myring, D F. A Theoretical Study of Body Drag in Subcritical Axisymmetric Flow. Aerospace Quarterly. Volume 3. 1976.

Aerodynamics Book

Dynamics Book

Library Book
Buoyancy

[B1] www.subconcepts.com

Mr. Fred Grey, subconcepts.com
Propulsion

Argrow Paper

MooG (Co. Documentation)
LSM

[LSM1] http://scienceworld.wolfram.com/physics/CylinderDrag.html & http://astron.berkeley.edu/~jrg/ay202/node20.html#drag-coefficient &
http://astron.berkeley.edu/~jrg/ay202/node21.html & www.eng.fsu.edu/~alvi/EML4304L/webpage/exp7description.doc

[LSM2] http://www.ledex.com

[LSM3] Robotics Sporting Goods

[LSM4] Murdock. Fluid Mechanics and its Applications. 1976.

AIAA Papers: 2001-2773. 2002-0124. 2002-0126.
Systems Engineer

Matt
Data Acquisition

Walt
Communications

ARRL Handbook

Shevell

Vable
Text Books:

Richardson. PADI Open Water Diver Manual. International PADI, Inc. 1999.

Burcher and Rydill. Concepts in Submarine Design. Cambridge University Press. 1994.

Robertson. Systems/Subsystems Investigation for a Multi-Sensor Autonomous Underwater Vehicle Search System. US Gov Agencies. April
1990.

Vable.l Mechanics of Materials. Oxford University Press. New York. 2002.

Shevell. Fundamentals of Flight (2nd Edition). Prentice Hall. New Jersey. 1989

Cengel. Introduction to Thermodynamics and Heat Transfer. Irwin McGraw-Hill. 1997.

Reed. The ARRL Handbook for Radio Amateurs 2002.The American Radio Relay League, Inc. 2001
03 Dec 03
RAV CDR Presentation
50
Supplemental Slides
Fluid Mechanics
Supplemental Slides
FM - Top level Design
4 Previous Designs considered




03 Dec 03
Florida Atlantic University’s “Squid II”
Mass. Institute of Technology’s “Orca 2”
Cornell University’s “CUAV”
University of Colorado’s HydroBuff R5-L UUV
RAV CDR Presentation
53
MINIMIZE DRAG GOAL
HydroBuff Shape
Decrease Outer Diameter
Decrease # of Control
surfaces
High Speed trimmability
6 inch outer diameter
Aluminum hull due
To availability
Trim vertically if
center of
Buoyancy is off
Trim laterally if
c.g. is not on
centerline
Aluminum Airfoils
NACA 0012
Myring Hull Contour
1 m overall length
Nose cone and
tailpiece shapes
3 in x 3 in
Alreco Aluminum
From
Propulsion
Sealing
Servo Specs
Use of Shroud
03 Dec 03
FINAL DRAG
RAV
CDR Presentation
COMPUTATION
54
FM - Mid-section Material
Comparison
Cost
Machinability
Compressive
Strength
Density
Risk
Comments
Stainless Steel
High
(about
$50 per
foot)
Moderate
High
High
(7.8 g/cm^3)
Moderat
e
Adds
excessive
weight which
will reduce
maneuverabilit
y.
Aluminum
Low
(about
$14 per
foot)
Excellent
Moderate
Low
(2.10 g/cm^3)
Moderat
e
Available in
desired sizes
from
manufacturer
in Colorado
PVC
Low
(about
$10 per
foot)
Excellent
Weak
(only up to 150 psi)
Low
(1.37 g/cm^3
Low
(Used
last
year)
Not available
in desired
sizes from
manufacturer
in Colorado
03 Dec 03
RAV CDR Presentation
55
FM - Preliminary Exterior Structure
Conclusions
Outer diameter of Mid-section was determined to
be 6 inches.



03 Dec 03
Tubing is typical made with outer diameters of 4, 6 or
8 inches.
Diameter was needed to be decreased from last
years 8 ¼ inch outer diameter in order to meet
maneuverability and speed requirements.
A nominal diameter of 4 inches was determined to be
too small to fit all required components inside the hull.
RAV CDR Presentation
56
FM - Control Surface Configuration
Considering 2 possible
control surface
configurations


Configuration 1: 2 dive
planes and two rudders
mounted on rear of
tailpiece
Configuration 2: 2 dive
planes mounted on the
nosecone and one rudder
located aft of the propeller.
Determined that vertical
and horizontal stabilizers
are unnecessary.
03 Dec 03
RAV CDR Presentation
57
FM - Control Surface Airfoil
Selection
Lift
Max α
(Max CL) (degrees)
Drag
Comments
(CD at
Max CL)
Area
Risk
Required
for Trim
NACA
0006
0.92
9 deg
0.010
183 cm2
Servo shaft
will have to
be about 1/8
inch
Symmetric
airfoil
NACA
0009
1.32
13.4 deg
0.016
127 cm2
Servo shaft
will have to
be less than
¼ inch
Symmetric
airfoil
NACA
0012
1.50
15 deg
0.025
110 cm2
Excessive
drag may
impede on
velocity
goals
Symmetric
airfoil
03 Dec 03
RAV CDR Presentation
58
FM - Airfoil Sizing vs. Shaft Sizing
Thickness
Max Shaft size Surface
(to allow for 0.05
Area
inches on either side)
required
NACA 0009
w/ 3 inch
chord
0.27 inches
0.17 inches
NACA 0009
w/ 3.5 inch
chord
NACA 0012
w/ 3 inch
chord
03 Dec 03
Drag
Coefficient
127 cm2
0.016
0.315 inches 0.215 inches
127 cm2
0.016
0.36 inches
110 cm2
0.025
0.26 inches
RAV CDR Presentation
59
FM - Airfoil Sizing Conclusions
A NACA 0012 airfoil with a 3 inch chord was
selected.

This will allow us to use a 1/8 inch Servo shaft
In order to use a 1/8 inch Servo Shaft with a
NACA 0009 airfoil, the chord length will have to
be at least 3 inches long.
Span required for this airfoil is 3 inches long
Aluminum was selected for material to be used
for control surfaces and Servo Shaft due to
excellent strength to weight ratios

03 Dec 03
Acrylic was not selected due to structural problems
with last years design.
RAV CDR Presentation
60
FM - Final Drag Computation
Final Drag Elements



Myring Hull Contour
4 NACA 0012 airfoils
Shroud w/ surface area of 669 cm^2
Final Drag computed to be 14.59 N at 5 knots
Reynolds Number = 2.5669 * 10^6, which makes
flow in the turbulent regime
Drag will not be tested directly. Drag data will be
based on thrust test data.
03 Dec 03
RAV CDR Presentation
61
Propulsion
Supplemental Slides
Torque Profile
Intermittent operation
is based on a 20%
duty cycle of one
minute on, four
minutes off.
RPM @ 5 knots
Torque as RPM changes
03 Dec 03
RAV CDR Presentation
63
Acceleration
T*V = η*P


Fix Power to 187.4 W
Step through V’s by 0.5
Find efficiency and thrust

F = ma
(Thrust – Drag)/mass = a
Problems

Efficiency is an approximation
Slippage and cavitations not
analyzed

Mass of vehicle
Added mass due to water

Acceleration values are much
larger than needed and
expected
03 Dec 03
RAV CDR Presentation
64
Rotary Shaft Seal
O ring
Bal Seals: 71x Series
Temp Range


Continuous:
-20ºF to +200ºF
Intermittent:
to +250ºF
Pressure: 60 PSI

RAV: 45 PSI max
Surface Speed: 4 m/s


RAV: 0.673 m/s @ 10 knots
Rated to 12,030 RPM
Coiled spring
03 Dec 03
RAV CDR Presentation
65
Propulsion Test Stopping Mechanism
Catch net


Nylon Seine net
PVC or wood frame on
two sides
Tension applied by 2
RAV team members
03 Dec 03
RAV CDR Presentation
66
LSM
Supplemental Slides
LSM - Detailed Drag Analysis
Method:
Cd vs. Re plot  Cd
Ftotal = FDrag + Finertia
Moment = F*r
Variables:
ρ = density
r = distance from axis of
rotation
ω = spin rate
D = diameter
dl= section length
CD = coef of drag
l = length of RAV
03 Dec 03
[LSM1]
L/2
FDrag  2 
0
1
 (r ) 2 ( Ddl )CD dr
2
FInertia   (l ) 2 D 2
L/2
Moment  2 
0
RAV CDR Presentation
1
 (r ) 2 ( Ddl )CD rdr
2
68
LSM - Solenoid Analysis
50% Duty Cycle

ON time/(ON + OFF) time
Maximum ON time
doesn’t exceed the specs
Specs




Stroke: 0.4±0.03”
Spring Rate: 4.41 lb/in;
0.45 lb ±30% preload
Weight: 12 oz
Dimensions: 1.875” x
1.935”
[LSM2]
03 Dec 03
RAV CDR Presentation
69
LSM - Comparison to previous jets
Similarities


Differences
Soft-Shift Solenoid
Overall plunger/latex
design

Theoretical Model
Integrated drag & moment
Inertia

Mount / Cavity
Minimize axial drag
Air bubble removal




03 Dec 03
Solenoid housing
Latex return
Use of o-rings
Circuit (not
microcontroller)
RAV CDR Presentation
70
Buoyancy
Supplemental Slides
Buoyancy - MATLAB Analysis
03 Dec 03
RAV CDR Presentation
72
Buoyancy - Stress Analysis & Mass
Flow Rate Calculation
03 Dec 03
RAV CDR Presentation
73
Project Management
Supplemental Slides
Drawing Tree - Full
03 Dec 03
RAV CDR Presentation
75
Detailed WBS
03 Dec 03
RAV CDR Presentation
76
Task List - Full
03 Dec 03
RAV CDR Presentation
77
PM – Detailed Budget
03 Dec 03
RAV CDR Presentation
78