Hand-Launched Electric Fuel Cell UAV Vehicles/Hand... · • Hand launchable by human of average...
Transcript of Hand-Launched Electric Fuel Cell UAV Vehicles/Hand... · • Hand launchable by human of average...
Hand-Launched Electric Fuel Cell UAVPT2020 High Endurance Aircraft
Critical Design Review | Senior Team 5
December 6th, 2010 | 10:45am
Team 5 Member Introduction
Agenda• Overview of Purpose & Mission• Design Requirements• Compliance Assessment• Approach • Program Plan• Design Walkthrough w/ Individual Reports• Appropriate Standards & FARs• Constraints & Risk Assessment Matrix• Failure Modes and Effects Analysis (FMEA)• Environmental, Societal, and Global Impacts
Purpose Statement“Produce a detailed design for a hand launched, fixed
wing, electric fuel cell powered Unmanned Aerial Vehicle (UAV) engineered for maximum endurance”
Lockheed Martin © Desert Hawk UAVAeroVironment© Raven B System UAVPhoto courtesy of www.lockheedmartin.comPhoto courtesy of www.avinc.com
Why Develop this UAV?• Electric fuel cell provides large possible performance
gains in small, hand launched UAV field• Hand launching enables quick and easy use in dynamic
situations (warfare, law enforcement)• Multi-mission versatility provides wide variety of uses• Provides a real world design task to learn introductory
design practices by trial & error methods• Enter a new niche in the UAV field
Simulation Video
AeroVironment© Raven RQ11 Simulation Videohttp://www.avinc.com/
Design Requirements • Hand launchable by human of average physical strength• Uses a real world, market available electric fuel cell• Payload of 200 in3 volume, 5 pounds, and 20 watts• 3 UAV units can be transported in a small pick up truck• Capable of skid landings• 25 to 35 knots speed range• 14,000 feet MSL service ceiling• 1,000 feet AGL operating altitude• Lockheed Martin Corporation©
Lockheed Martin © Desert Hawk UAVPhoto courtesy of www.lockheedmartin.com
Baseline Deliverables
B Level Team Grade
Mechanical Design and 3D Render
Risk Matrix, and Risk Mitigation
Plan
Aerodynamic Analysis
Requirement Derivation Project Plan
(Gantt Chart)Performance
Analysis
Requirements Verification
Matrix
Supplementary DeliverablesCompleted Extra
Deliverables
Production Feasibility
Range & Endurance
Calculations
Cruise Speed Calculations
Interior Structural
DesignCost Analysis
Control Surfaces
CAD Modeling
Disassembly Methods
Future Possibilities
Longitudinal Aerodynamic
Stability
Component CAD
Modeling
Interior Structure
CAD Modeling
Design Outline3.7 Meters (12.4 Feet)
Wingspan
1.9 Meters (6.3 Feet)Tip-To-Tail
17 Inch DiameterPropeller
9.1 Kilograms (20.1Pounds)
Total Mass
Compliance Assessment• Hand Launchable• Electric Fuel Cell Usage• Payload Specifications• Transportability • Skid Landing Capable• Speed Range• 14,000 Feet MSL Service Ceiling• 1,000 Feet AGL Operating Altitude
Compliance Assessment• Hand Launchable
– Challenges of Weight, Wingspan, and Takeoff Velocity– Built a Prototype UAV: Same Mass & Dimensions – Tested by Performing 3 Test Throws
Compliance Assessment
Hand-Launchable Test Compilation VideoTeam 5 Recorded 11/22/2010
Compliance Assessment• Powered by Electric Fuel Cell
– Choose Horizon Energy Systems Aeropak• Payload Requirements
– UAV has 200 in3 volume, 5 pounds, and 20 watts payload split into two compartments
Compliance Assessment
– Easily Transport 3 UAVs in the Truck Bed
– Chevy S10 Truck Modeling (72” x 50”)
• Transportable by Small Truck
Compliance Assessment• Capable of Skid Landing
– Designed to Sustain Impact– However, Computational Analysis &
Real Testing was Not Completed– Time and Expertise
Compliance Assessment• 25 to 35 Knots Speed Range
– Meets min/max cruise speed– Stall speed never exceeds 18 knots– Maximum dash speed is 65 knots, cruise at 35 kts
has 5 hours endurance• 14,000 feet MSL service ceiling
– Operating altitude up to 14,000 feet– Speed requirements met at 14,000 feet
• 1,000 feet AGL operating altitude
Assessment Conclusions• Hand Launchable• Electric Fuel Cell Usage• Payload Specifications• Transportability • Skid Landing Capable• Speed Range• 14,000 Feet MSL Service Ceiling• 1,000 Feet AGL Operating Altitude
Approach• Identify Driving Requirements• Initial Sizing as Team• Breakdown into Components• Integrated Design• Identified Problems • Rebuilt from Basic Sizing to Solve Problems• Performed Computational and Physical Tests• Finalized Design • Calculated Capabilities
Program Plan
Start Date: September 8th, 2010
Requirements Defined: September 24th, 2010
General Sizing: October 8th, 2010
Preliminary Design Review: October 29th, 2010
Critical Design Review: December 6th, 2010 (Today)
Requirements Re-Evaluation: November 12th, 2010
Nick Kranowski Task Report
Component Integration
Appropriate Standards
Design Reviews
Presentation
Sponsor & Faculty Liaison
Requirement Derivations
& Matrix
Systems Engineering
Design Walkthrough
How Does a Fuel Cell Work?• Water from the
reservoir is separated• Hydrogen enters Anode
and breaks down• O2 enters Cathode and
breaks down• Hydrogen Protons
migrate through PEM• Electrons pass around
PEM
Video courtesy of www.howstuffworks.com
Fuel Cell Selection• Horizon Energy Systems Aeropak
– Available Power: 240 Watts (Sea Level)
– Available Continuous Current: 10 Amps
– Output Voltage Range: 20-32 Volts
– Mass (w/ Fuel Cartridge): 2 Kilograms
– Deliver Up to 900 Watt-hours Photo courtesy of www.sae.org
Fuel Cell Advantages• Batteries to Fuel Cells
– Lithium ion battery: 150Wh/kg– Horizon Aeropak: 450Wh/kg– 3x Improvement
• Benefits of Fuel Cells– Have endurance of 3x that
of comparable batteries– Easy refueling (no recharge)
Battery Type Energy Density (kJ/kg)Lead – Acid 79.2
Lithium Polymer 602Sodium – Sulfur 792
Mg hydride with Ni catalyst 8,280Gasoline 47,500Hydrogen 120,000 – 142,000
Altitude Restriction
Photo courtesy of www.horizonfuelcell.com
Addition of Battery Pack • Initial estimates showed insufficient speed/altitude• Battery pack needed to extend flight envelope• Takeoff and climb assistance• Choice: Thunder Power Pro
Lite MS Series TP-40004S2PL• Endurance = 4000mAh• Constant Voltage = 14.8V• Max Burst Current = 100A• Weight = 338g Photo courtesy of www.rctoys.com
Electronic Speed Control• Castle Creations Phoenix 60 ESC• Max Current = 60A• Weight = 58g• Programmable with auto-shutoff• For brushless motors
Photo courtesy of www.rctoys.com
• Fuel Cell Selection– Horizon Energy Systems Aeropak– Zero greenhouse gas emissions– Greater endurance than batteries– Longer range
• Further work– Research fuel cells with higher energy densities– Increase altitude operation of fuel cell
Individual Conclusions & Recommendations
Cameron Japuntich Task Report
Plane Storage
Modeling
Motor & Motor
Controller Assistance
Fuel Cell Limitation Research
Propeller Selection
AssistanceGantt Chart
Creation
Fuel Cell Selection
Wing Design
Wing Design
Wing Design
Chart courtesy of Aircraft Design (Raymer)
Wing Design
Wing Design• Using metal CNC die, carbon wing shell can
be vacuum bag molded• Use of mold/casting methods eliminates
need for foam core• Vacuum bagging produces lightest weight
and highest quality • Carbon wing spar with honeycomb internal
structure offers high weight to strength
Individual Conclusions & Recommendations• Conclusions
– Low Reynolds flow is a growing field– Structural analysis of composites is difficult
• Recommendations– Full FEA analysis of wing structure– Thorough verification of aerodynamic characteristics
using more advanced CFD– Talk to composites expert about best options
Garrison Hoe Task Report
Cost Analysis
Assistance
Analysis of Wing
Capabilities
Wing Structure & Materials
Risk Matrix Mitigation
Plan
Failure Modes and
Effects Analysis
Wing Airfoil Selection
Tail Structure
Tail Design
Airfoil Selection Tail•
Tail Control Surfaces• Rudder and elevator are usually 90% span
starting at fuselage with 25-50% of chord• Taper ratios are same as tail’s
• UAV tail is sufficient for stability• Matches specifications based on main wing
dependence• More tail loading analysis to minimize weight• Tools like ANSYS could be used• Further research into composites• Review NACA 0015 airfoil (increases stalling angle)
Individual Conclusions & Recommendations
Fuselage Design Factors
PerformanceSkid Landing
Payload SupportTruck TransportHand Launched
Structures
Materials Profile
Dimensions
Bottom-Up Design
Component Selection & Sizing
Component Layout
Profile and Cross Sections
Lofting and Structures
Stability and Performance
Requirements
Materials
• Major Components• Fuel Cell• Avionics Payload• Motor
• Minor Components• Motor Controller• Servos• Battery
Avionics Camera• Cloud Cap Technologies
Tase LT• SWAP: (12.1 x 9.71 x 8.99)
cm, 1 lb and 10 W• Sony FCB-IX11A EO
camera with 10x optical zoom
Photo courtesy of www.cloudcaptech.com
Component LayoutBattery
Motor
Front Payload
Fuel CellRear Payload w/
Camera
Fuselage Exterior
Structures and Materials• NACA inlets• Carbon fiber-Kevlar
hybrid Skid Plate• Lexan Camera
Protection• Carbon fiber balsa core
bulkheads and firewall• 2 layers of twill weave
carbon fiber body• Mass=670 g, L=0.985 m Photo courtesy of www.dragonplate.com
Tail Boom• Length=87 cm,
Diameter = 3.81 cm • Mass = 200 g• 1 mm thick carbon
fiber epoxy• Carbon fiber-Kevlar
Hybrid skid plate• Detachable from
fuselage
• Structural Analysis Required– Impact Analysis, FEA
• Wind Tunnel Testing on scale model– Verify XFLR5 data
• Highly desirable for military operations– Long range, transportable, hand launched
Individual Conclusions & Recommendations
Greg Hoepfner Task Report
CAD Modeling Internals
CAD Modeling Fuselage
CAD Modeling Tail
Boom
CAD Modeling
OML & Final UAV
XFLR5 Full UAV Analysis
Fuselage Design
Airfoils Selection• Wing root uses S4022 airfoil• Wing tip uses Wortmann FX 60-126 airfoil• S4022 is design for low Reynolds number and
high lift• Wortmann FX 60-126’s geometry is design to
achieve aerodynamic twist for stability• Use XFLR5 to analyze the wing
Wing Aerodynamics• Based on the wing analysis, take-off speed at
sea-level is:
• The initial estimated weight is 7 kg• This is only based on the wing’s aerodynamic
analysis.
m/s 89.822.12/1
max
=
=
LTO CS
WVρ
-5 0 5 10 15 20-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
angle of attack, α (degree)
Lift
coef
ficie
nt, C
L
CL vs α
Main WingAircraft
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.80
0.05
0.1
0.15
Lift Coefficient, CL
Dra
g co
effic
ient
, CD
Drag Polar
Main WingAircraft
Aircraft Aerodynamics• Static Margin
– 13% of the Chord
• Center of Gravity– 55.2 cm from the nose– Change in the fuel has a negligible effect on the
center of gravity
13.0=−= cgnn hhK
Longitudinal Aerodynamic Stability Derivatives
Derivatives• Axial force due to velocity• Axial force due to “incidence”• Axial force due to pitch rate• Axial force due to downwash lag
• Normal force due to velocity• Normal force due to “incidence”• Normal force due to pitch rate
Value1019.0−=uX
4534.0=WX0498.0−=qX0158.0−=•
WX
732.1−=uZ425.4−=WZ
2150.2−=qZ
Longitudinal Aerodynamic Stability Derivatives
Derivatives• Normal force due to downwash lag• Pitching moment due to velocity• Pitching moment due to “incidence”• Pitching moment due to pitch rate• Pitching moment due to downwash lag
Value7026.0−=•
WZ
0≈uM7484.0−=WM
1838.2−=•W
M8846.6−=qM
• Use XFLR5 to analyze the aircraft with elevator, rudder, and ailerons on
• Perform lateral stability analysis• Perform second iteration of longitudinal
stability analysis• Match XFLR5 Model with CAD model• Perform Stability Augmentation analysis
Individual Conclusions & Recommendations
Chandra Tjhai Task Report
XFLR5 Profile
Calculations
Hand Launchability
AnalysisAerodynamic Calculations
Center of Mass
Identification
Longitudinal Stability
Calculations
Real World UAV
Research
Components/Avionics
Components/Avionics
02468
1012141618
0 50 100 150 200
Torq
ue R
equi
red
(kg-
cm)
Control Surface Span (cm)
Torque Required
2cm Chord4cm Chord6cm Chord8cm Chord10cm Chord12cm Chord
RudderAileron Elevator
Flap
Components/Avionics
• MKS DS450• Weight: 9.5g• Torque: 3.1 kg-cm
• BMS-306MAX• Weight: 7.1g• Torque: 1.6 kg-cm
• BMS-820DMG• Weight: 45g• Torque: 9.2 kg-cm
Ailerons & Elevator Rudder Flaps
Image courtesy hobbyking.com Image courtesy modellbauen.ch Image courtesy romaniamall.ro
Motor and Propeller
Motor• Lightweight and efficient• Effective at various power
levels• Brushless• No gearbox necessary• Small enough for
fuselage• Sufficient documentation
Propeller• Folding propeller for skid-
landing• Large enough to provide
thrust required• Maximum efficiency at
upper speed limit• Matched diameter/pitch
with motor RPM
Motor and Propeller• Motocalc used to
model efficiency• Entire range of
documented motors iterated
• Propellers from 10”x5” up to 24”x12”
• Tested at fuel cell rated power output: 200W
Motor and Propeller
Motor• Neu 1915-2Y• Kv = 360 RPM/V• Weight = 397g• Max rated power =
1800WPropeller• Aero-Naut CAMcarbon
folding propeller• 17” diameter by 11” pitch
Image courtesy fastelectrics.com
Image courtesy hacker-motor-shop.com
Motor and Propeller• 63% total propulsive
efficiency at 35kts• 32N static thrust at
600W: 4m/s2 takeoff acceleration
• Sufficient power for launch speeds down to 7 m/s
Performance Analysis
Without Battery• Max
Altitude = 11500 ft
• Max Velocity = 37 kts
Performance Analysis
With Battery• Altitude and
velocity no concern
Performance Analysis
• Max ROC = 9.6 kts
• Climb 1000ft in 62s
0
2
4
6
8
10
12
0 2000 4000 6000 8000 10000 12000 14000 16000
Rat
e of
Clim
b (k
ts)
Altitude (ft)
Maximum Rate of Climb
Max ROC
Max ROC with Battery
Performance Analysis
y = 989.03x-1.07
0
2
4
6
8
10
12
14
16
0 50 100 150 200 250
Endu
ranc
e (h
rs)
Power Output (Watts)
Endurance vs. Power Output
Performance Analysis
0
2
4
6
8
10
12
0 2000 4000 6000 8000 10000 12000 14000 16000
Endu
ranc
e (h
rs)
Altitude (ft)
EnduranceTakeoff Velocity
Takeoff Velocity With Battery
25 kts Cruise
25 kts Cruise With Battery
35 kts Cruise
35 kts Cruise With Battery
• Max Endurance: 10.3 hrs
Performance Analysis
0
50
100
150
200
250
0 2000 4000 6000 8000 10000 12000 14000 16000
Ran
ge (n
mi)
Altitude (ft)
Range25 kts Cruise
25 kts Cruise With Battery
35 kts Cruise
35 kts Cruise with Battery
Maximum Range
Maximum Range with Battery
• Max Range: 235nmi
• Achieved at 11000ft, 30.7 kts
• Fuel cell technology needs more improvement for aerospace applications
• Documentation of fuel cells on the market very lacking• Fuel cell difficult to model in performance-estimating
applications• A lighter payload and/or no hand-launch restriction would
allow greater performance• ANSYS data could provide better drag characteristics
Individual Conclusions & Recommendations
Erik Eid Task Report
Speed Controller Selection
Motor & Propeller Selection
Performance Analysis
Range & Endurance Calculation
Altitude & Speed
Analysis
Avionics Analysis
Risk AssessmentRisk Probability Impact
Fuel Cell Operation at High Altitude Medium High
Light-weight Composite Wing & Fuselage Design High Low
Meeting Hand Launch Requirement Low High
Meeting Speed/Altitude Requirements Medium Medium
Aircraft Aerodynamics and Static Margin Medium Medium
Prop Strike on Skid Landing Low Low
High Lift Devices (Flaps) High Low
Easy Assembly on Ground Low Medium
FMEAMODES OF FAILURE PROBABILITY SEVERITY SOLUTION
Wing structural failure Low HighFEA and flight testing aswell as frequent field inspections
Control surface detachment Low Medium Kevlar hinges and flight
testing
Fuel cell malfunction Low HighEnsure that fuel cell is operated within manufacturer limits
Aircraft loses control Extremely Low HighControl surfaces have programed default positions that spiral airplane
Engine failure Extremely Low Medium Emergency landing required
Prop strike on hand launch Low Medium
Prop is located in the front of aircraft away from launcher
FMEAMODES OF FAILURE PROBABILITY SEVERITY SOLUTIONBird strike Extremely Low High No solutionLithium Polymer battery explosion Low High Follow Li-Po handling
procedure
High winds Medium Medium Set thresh-hold for operable wind conditions
Icing Extremely Low HighDefine environmental constraints or install anti-icing for wings or pito-probe
Hard impact on skid landing Low Medium
Kevlar and impact foam implemented for shock absorption
Damage during ground transport Low Medium
Transportation case is designed to take abuse while retaining internal integrity
Federal Aviation Regulations• Two means of operating UAS in NAS outside of “restricted” airspace
– Special Airworthiness Certificate – Experimental Category– Certificate of Waiver or Authorization (COA)
• FAA created the Unmanned Aircraft Program Office (UAPO) and the Air Traffic Organization (ATO) UAS office to help integrate UASs into the NAS
• FAA is working with members of the UAS community to define operating and certification requirements that are critical for allowing UAS access to the NAS
• The FAA has tasked RTCA to advise on technical issues of developing UAS standards targeted to be complete before 2015. Two questions that need answering;– How will UASs handle communication, command, and control?– How will UASs “sense and avoid” other aircraft?
Source: www.faa.gov, Published Sept. 20, 2010
Production Feasibility• Wing and tail are the hardest parts to build• Creativity skills needed, especially for homebuilt• Material selections important
– Heavy fuel cell– Met hand launch requirement
• Not hard to build from industrial point of view
Cost AnalysisCOMPONENT DESCRIPTION COSTWings Total Cost $250
5.7oz 3k 2x2 Twill Carbon Fiber $48.06Honeycomb Dragon Plate $154.86Balsa $20
Fuselage Total Cost $2005.7oz 3k 2x2 Twill Carbon Fiber $38.80Carbon/Kevlar Twill $6.181/8” Lexan $3.45Balsa Core Dragon Plate $134.80
Tail Boom Total Cost $130Carbon Fiber Tube $120Carbon/Kevlar Twill $1.33
Cost AnalysisCOMPONENT DESCRIPTION COSTElectronic Components
Total Cost $671
Servos $227.95Brushless Motor $2354000mah 4S Li-Po Battery
$189.99
Prop and Spinner $18Tail Total Cost $47
Carbon Shell $21EPS Foam Core $6Carbon Tube $20
Aircraft Materials Cost(Fuel Cell Not Included) $1300
Environmental Impacts• Environmentally Friendly
– No Greenhouse gas emission– Requires no recharge– Byproducts are water and heat– Step away from dependence on
harmful batteries• Concerns
– Aided by lithium battery use (disposal is hazardous to environment)
– Need to create a recycling procedure
Photo courtesy of www.constructiondigital.com
Societal Impacts• UAV potential search operations • Lead to more extensive research
in fuel cell technology• Displace human (solely) pilots • Invasion of privacy regarding
citizen spying• Air traffic control issues in
domestic flight patterns• Possible bomb usage at further
distances, lessening moral conflictPhoto courtesy of
www.acecombatskies.com
Global/Military Impacts• Can provide battlefield
intelligence to save lives • Creates new role for quick-
deploying, high endurance surveillance
• Benefits allies on the United States of America in areas of high secrecy and security
• Large hydrogen consumption (more efficient hydrogen isolation methods needed)
• Provide exploration of dangerous territory
Photo courtesy of New York Times Newspaper
Hand-Launched Electric Fuel Cell UAVPT2020 High Endurance Aircraft
Critical Design Review | Senior Team 5
December 6th, 2010 | 10:45am
APPENDICES
Additional Documentation
NACA 64-012A
NACA 64-012A
NEW Recommendations from Steve of Tail Airfoil Selection
NACA 0015 SPECS RECOMMENDATION FROM STEVE
Mass Balance
Mass Balance
Aircraft Aerodynamics• Static Margin
−+=
αε
dd
aaVhh Tn 11
180)(180
cos5.0
180 cos5.0
180 cos5.0
180 cos5.085
5 22
22
22
2
22
2
2
2
π
π
π
π
π
παε ∑
=
++
+
+
++
+
+
=fi zx
x
zfi
zfixx
zfix
fi
Ara
dd
1822.0=−= cgnn hhK
Longitudinal Aerodynamic Stability Derivatives
• Aerodynamics of aircraft
At trim condition (C_M = 0):
/rad372.4=a /rad784.41 =a m 4086.0=c m 27.1=Tl
/rad3172.0=αε
dd
45.0=TV /rad784.41 =a
m/s 14V 053.0C 866.0 7.4 0D ===°= LCα
0 0
/rad1076.0 s/m 0003175.0 /rad4125.0
≈∂∂
≈∂∂
=∂
∂−=
∂∂
=∂∂
VC
VC
CVCC
ML
T
DDD T
αα
Longitudinal Aerodynamic Stability Derivatives
VSVVCVCX D
Du ∂∂
+∂∂
−−=τ
ρ 0
0
21
12
α∂∂
−= DLW
CCX
T
DTq
TC
VXα∂
∂−=
αε
ddXX q
W=•
Aircraft Aerodynamics• Use XFLR5 to analyze the aircraft aerodynamics
Longitudinal Aerodynamic Stability Derivatives
VCVM M
u ∂∂
= 0
αddCM M
W =
claVM T
Tq 1−=
αε
ddMM q
W=•
VCVCZ L
Lu ∂∂
−−= 02
α∂∂
−−= LDW
CCZ
1aVZ Tq −=
αε
ddZZ q
W=•
Real World Large Scale UAVs
ASM Swift Flight Hand Launched Flight Videohttp://www.youtube.com/
Component Placement
Truck Transportation Methods
Wing XFLR5 Analysis
Wing Polars from XFLR5
First Order Airplane Polars From XFLR5