1
Aerospace Thermal Management Challenges and Solutions, A Boeing Perspective
Jim RoblesPhn: 253-657-5663
Email: [email protected]
Reference Number: 07-045
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The Aerospace Thermal Management Challenge
Avionics / Vetronics• Fighters, Helicopters, and
Ground Vehicles More Electric Aircraft and Directed Energy Systems
• The Need for Ultra Efficient Energy Systems
Some Technologies that Boeing is Investigating
• Lightweight Carbon Thermal Management Systems
Aircraft Power Trends2500 HP
2000 HP
1500 HP
1000 HP
500 HP
0 HP
1940 1950 1960 1970 1980 1990 2010
1.5 MW
750 KW
1.125 MW
KC-135
A-7
A-10
SHUTTLE
B-29
B-47
B-52A
B-52G
B-52H
B-1
B-2
C-130 C-141
C-17
C-5
E-8
E-3
E-4
AF-1
F-104
F-86D F-100
F-106
F-4
F-111
F-16
F-15
F-117
F-22
P-51
F-35
E-10A
7E7
Increasing power demands equate to increasing thermal managementIncreasing power demands equate to increasing thermal management needsneeds
Graphic courtesy of Rengasamy Ponnappan, Ph.D., Senior Researcher, AFRL/PRPS
Agenda
Reference Number: 07-045
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The Aerospace Thermal Management Challenge
Avionics/vetronics functional density driven by inexhaustible demand for:
• Greater Processing Capability for Image Exploitation including Automatic Target Recognition, Moving Target Engagement, etc.
• COTS components and assemblies with lower temperature limits
More Electric Vehicles (MEV) for weight and power
• Substantial increase in vehicle requirements for electrical power and cooling
• Remote actuationDirected Energy Weapons (DEW)
• Substantial energy to be delivered at low efficiency
• Integrate on existing platforms: no desire for “DEW Platform”
Reference Number: 07-045
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COTS Applicability
Future
More of the same“office environment”
Future
More COTSVPX/REDI
Graphic courtesy of Mercury Computing
System Mission CriticalFunctional
DensityEnvironment
Sample Assembly Item
Insight into Assembly Item and Ability to
Influence
C-32 / C-40 No (VIP Aircraft)Low
(Commercial Aircraft)
Benign Ricoh Printer Lowest
AWACS 40/45 Dell Server
P-8A ATCA
F/A-18Custom and
VMEHighest
F-22Custom and
VMEHighest
FCS VPX and Redi High
Medium
YesHigh (fighter,
helicopter, ground vehicle)
Severe
Medium Medium
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High Functional Density, Severe Environment Military Platform Needs
Minimize Total Ownership Cost (TOC) Development Cost Unit Recurring Flyaway (URF) Cost Operation and Support (O&S) Cost
High functional density to minimize weight and volume Thermal density (watts/cm)
Perform reliably in harsh environment Compatibility with two-level maintenance for
Reductions in life cycle cost Reductions in logistic footprint
Facilitate insertion of new technology and mitigation of component obsolescence Thermal margin Open system standards
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The Challenge
Customer Needs - The Challenge and the Opportunity
Functional
Densit
y
Power per Function
Thermal Density
Allowable Component Temperature
Functional
Densit
y
Power per Function
Thermal Density
Allowable Component Temperature
Functional
Densit
y
Power per Function
Functional
Densit
y
Power per Function
Thermal Density
Allowable Component Temperature
Thermal Density
Allowable Component Temperature
Thermal ManagementContinuing Loss of Control of
the Electronics Industry
0
10
20
30
40
1980 1990 2000 2010
Piece parts -mil-spec % of
total
Equipment -military % oftotal avionics
Source: AvionicsMagazine, 01/01
Source:TACTech,’95
Per
cen
t
Processing Requirements AKA Functional Density
The Opportunity
References: www.vita.com and http://www.busandboard.com/archive-index.html
Open Architecture Standards &a Strong Industrial Base
Two-Level Maintenance
VITA 48 ERDI (Enhanced Ruggedized Design Implementation)
IBM Cell Processor Technology
•Enhanced thermal management and functional density•Two-level maintenance compatibility•Conduction and air cooling to 200 watts •LFT and spray cooling to 800 watts
•Moving target engagement
•Automatic target recognition
Graphic courtesy of Mercury Computing
VITA 46 VPX•High speed serial interconnect switch fabric based architecture•Market driven selection of bus protocols•ESD protected connectorANSI/VITA 47-2005•Open architecture standard for environments
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The COTS Trade – Circa 1998
Option Affordability Survivability/Lethality Supportability
Development Cost
Design To Cost (DTC)
O&S Cost Weight Volume Performance (watts per inch of
pitch)
Integrity/ Reliability
Ease of Maintenance
Ease of Technology
Insertion
Liquid Flow Through (LFT) Cooled Custom
Design
Baseline Baseline Baseline Baseline Baseline 500 High Good High (100% thermal margin)
Air Flow Through Cooled Custom
Design
No change from Baseline
No change from baseline
No change from baseline
1.5 times baseline + ECS
effect
1.5 times baseline + ECS
effect
333 Medium Good High (100% thermal margin)
Conduction Cooled Custom
Design
No change from Baseline
High High 3.4 times baseline
3.4 times baseline
145 Low Good Extremely Poor
Conduction Cooled COTS
Lower Lower Higher Eight (8) times Baseline
Eight (8) times Baseline
63 Low Poor Extremely Poor
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Advances in Conduction Cooling
F-22 CNI/EW Power Supply• Circa 1993 to 2000
• SEM-E
• ~ 40 watts
• Military Grade Temperature Components
• No “special” technology
IEEE 1101.2 VME Card• 2000 to 2005
• 6U
• Up to 90 watts
• ~ Industrial Grade Temperature Components
• Extra conduction paths
VITA 48 Module• Circa 2006
• 6U
• 200 watt capability
• ~ Industrial Grade Temperature Components•Heat pipes, extra conduction paths
• Aluminum/Beryllium is being used in the F-22 CNI/EW power supply module.
• AlBe selected for CTE match to PWBmaterial, to minimize strain on solder jointsof large packages.
• Weight benefit of -0.065 pound per module.
• Cost upper of $400 per module.
• ~$6,200 per pound of weight saved.
• Health and process issues resolved.
Graphic courtesy of CWCEC
GRAPHICGRAPHICNOTNOT
AVAILABLEAVAILABLE
Current Custom Module• Circa 2006
• 6U
• 110 watt capability
• ~ Industrial Grade Temperature Components•APG Core• Large Wedge Clamps
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Advances in LFT Cooling
• Aluminum/Beryllium was considered for use inCIP power supply module cores.
• AlBe was not required for CTE match.
• -0.065 pound of weigh saving would have cost$585 ($9400/pound saved).
• Cost not considered justified by the F-22Program.
• Aluminum cores.
F/A-22 CIP Power Supply• Circa 1993 to 2000
• SEM-E
• ~ 80 to 100 watts
• Military Grade Temperature Components
• Quick Disconnect (QD) Issues
Custom Design Processor• Circa 1996 to 2000
• SAM (6U-ish)
• 140 watts design / 300 watt capability
• Industrial Grade Temperature Components
• QD Issues Worked
VITA 48 Module• Circa 2006
• 6U
• 600 to 800 watt capability
• ~ Industrial Grade Temperature Components
• QD Issues Being Worked
Graphic courtesy of Mercury Computing
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The COTS Trade - Circa 2006VPX/REDI => low total ownership cost, excellent weight, volume, performance, and good supportability.
PoorGoodMedium1006 x Baseline6 x BaselineHighHighConduction Cooled Custom
Medium (30% Thermal Margin)
GoodHigh2003 x Baseline3 x BaselineLowConduction Cooled COTS
Marginal
(Zero to 33% Thermal Margin)
Good500 to 800LowInternal Spray Cooled COTS
Medium
(16% to 67% Thermal Margin)
PoorHigh700 to 1000Baseline plus pump module
or external HRU
Baseline plus pump module
or external HRU
MediumDirect Spray Cooled COTS
Medium
(25% Thermal Margin)
GoodHighest750BaselineBaselineLow$15k
(typical)
LowLFT Cooled COTS
Marginal
(Zero to 33% Thermal Margin)
Good500 to 800HighVery HighInternal Spray Cooled Custom
Medium
(16% to 67% Thermal Margin)
PoorHigh700 to 1000Baseline plus pump module
or external HRU
Baseline plus pump module
or external HRU
Very HighDirect Spray Cooled Custom
Marginal (Zero Thermal
Margin)
GoodHighest5001.2 X Baseline
1.2 X Baseline
High$35k
(typical)
HighLFT Cooled Custom
Ease of Technology
Insertion
Ease of Maintenance
Integrity/ Reliability
Performance (Watts per
inch of pitch)
VolumeWeightO&S CostDesign To Cost (DTC)
Development Cost
SupportabilitySurvivability/LethalityAffordabilityOption
PoorGoodMedium1006 x Baseline6 x BaselineHighHighConduction Cooled Custom
Medium (30% Thermal Margin)
GoodHigh2003 x Baseline3 x BaselineLowConduction Cooled COTS
Marginal
(Zero to 33% Thermal Margin)
Good500 to 800LowInternal Spray Cooled COTS
Medium
(16% to 67% Thermal Margin)
PoorHigh700 to 1000Baseline plus pump module
or external HRU
Baseline plus pump module
or external HRU
MediumDirect Spray Cooled COTS
Medium
(25% Thermal Margin)
GoodHighest750BaselineBaselineLow$15k
(typical)
LowLFT Cooled COTS
Marginal
(Zero to 33% Thermal Margin)
Good500 to 800HighVery HighInternal Spray Cooled Custom
Medium
(16% to 67% Thermal Margin)
PoorHigh700 to 1000Baseline plus pump module
or external HRU
Baseline plus pump module
or external HRU
Very HighDirect Spray Cooled Custom
Marginal (Zero Thermal
Margin)
GoodHighest5001.2 X Baseline
1.2 X Baseline
High$35k
(typical)
HighLFT Cooled Custom
Ease of Technology
Insertion
Ease of Maintenance
Integrity/ Reliability
Performance (Watts per
inch of pitch)
VolumeWeightO&S CostDesign To Cost (DTC)
Development Cost
SupportabilitySurvivability/LethalityAffordabilityOption
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Future Combat Systems is using a VITA 46 COTS Solution
Backplane (BP) – ruggedized circuitry for intra-rack power and signal distribution; includes backplane interconnect, I/O connectors, backplane to I/O connector harness, and backplane cover
Backplane
6U 3UCircuit Cards – Per VITA 46• Functional Density• High speed serial interconnect with switch fabric matrix architecture• ESD protected connectorEnvironments – Per ANSI/VITA 47-2005• Open architecture standard
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Future Combat Systems has committed to 2-Level Maintenance Utilizing VITA 48
Table 2. FCS Maintenance Levels Trade Study
VITA 48 Module with ESD protected connector and covers
Integrated Electronics Rack (IER) – the enclosure in which LRMs are installed; provides mechanical support, cooling and some measure of environmental protection to the LRMs; provides the physical interface to the platform; includes backplane interface
6U 3U
Line Replaceable Modules (LRM) – Per VITA 48• Covers for ESD protection also provide stiffening and greater EMCMeets the Army’s Needs • $4B operation and support (O&S) cost reduction for Integrated Computer System (ICS) alone• Greater than 50% reduction in logistics footprint• Corresponding benefits for other systems.
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Cooling Capacity vs. Functional Density Requirements
Key to survivability and effectiveness COTS vs. Custom advantages The Future => 600 watt 6U card with four processor nodes
Cooling Capability vs. Functional Density Requirements 1998 - 2008
0
100
200
300
400
500
600
700
800
1998 2000 2002 2004 2006 2008
Po
wer
(Watt
s)
COTS LFT
Functional Density Requirements
COTS Conduction
Custom Conduction
Custom LFT
Reference Number: 07-045
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MEA and DEW Systems Require Ultra Efficient Energy Systems
Need:Energy system technologies that provide dramatic improvements in capability and
affordability
Need:Energy system technologies that provide dramatic improvements in capability and
affordability
Technologies: • Integrated Electric Vehicles
• Efficient Electrical Subsystems
• Thermal Management
• Power Generation, Conversion, Distribution and Storage
Technologies: • Integrated Electric Vehicles
• Efficient Electrical Subsystems
• Thermal Management
• Power Generation, Conversion, Distribution and Storage
More efficient, cost effective, electrically powered systems
Enable integration of Directed Energy Weapons
Unprecedented requirements for
energy generation, distribution, and
storage accompanied by increased thermal
management demands
Reference Number: 07-045
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Some Technologies that Boeing is Investigating
Pulsating & Loop Heat Pipe Integration
Spray Cooling
CNT Thermal Interface
Graphitized Graphitic FoamHiDRA - BRI
Engine Power Extraction
CompactPower Panels
AC MatrixController
Advanced Motor Controllers
Adv Batteries
Fuel Cells
Rad Hard, High Temp Devices
Liquid Flow Through Cooling
Reference Number: 07-045
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Commercialization Plan
A high-conductivity carbon-carbon composite enclosure
for the aircraft avionics enclosure
• Carbon Foam
• Carbon/Carbon Composites
• C-C Foam
• High Conductivity Adhesives
• Phase Change Material Thermal Planes
• 20% Weight Reduction• 15% Extended Component Life
High Conductive Carbon Thermal Management Material System
Passive Cooling
Aircraft Avionics Enclosure
Derivatives Technologies
• Reduced Coolant Pumping Power• Improved Thru-the-Wall Thermal Conductivity
Enclosure
Carbon Foam Cold Plate
Lightweight Carbon Thermal Management Systems (LC-TMS)
A high-conductivity carbon-foam thermal cavity for a thermally integrated, structurally embedded electric actuator.
Structurally Embedded Actuator
• 37.7% Acquisition Cost Saving• 43.1% LCC Saving
X-45ElectromechanicalActuator
Long-Range StrikeC-17
Nano Enhanced Composite Skin
Reference Number: 07-045
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Conclusions
The aerospace thermal management challenge is driven by • More Electric Aircraft (MEA)• Directed Energy Weapons (DEW)• Increased Power and Heat Flux in Avionics/Vetronics
Thermal Management is quickly becoming a limiting design factor for future military aircraft and satellites
The design of the thermal management system must address the ability to reject heat from remote electronics including their true operational duty cycle/s
Future cooling demands will require an integrated thermal management strategy at the platform, subsystem, and component levels
Advanced materials are being developed that will enable an integrated subsystem approach to thermal management
• Thermally conductive carbon foam materials • Phase change materials• Nano technologies
Reference Number: 07-045
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Backup
Reference Number: 07-045
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Two-Level Maintenance
Three-Level Maintenance Two-Plus-Level Maintenance Two-Level Maintenance
LRU R&R at the O-Levelo Requires ESD/Handling protection at the LRU interfaceo Requires fault isolation to the LRUo Requires sparing; much larger, heavier, and more expensive; LRU’s
LRU R&R at the O-Levelo Requires ESD/Handling protection at the LRU interfaceo Requires fault Isolation to the LRUo Requires sparing; much larger, heavier, and more expensive; LRU’s
LRM R&R at the O-Levelo Requires ESD/handling protection a at the module/card interfaceo Requires fault isolation to the LRMo Requires sparing; much smaller, lighter, and less expensive; LRM’s
R&R modules/cards at the I-Levelo I-Level Shop is expensive, vulnerable, and difficult to transport
I-Level Shop not required I-Level Shop not required
Card/module repair at the Depot Card/module R&R and repair at the Depot LRM repair at the Depot
-
Radar Processor
-F- 22 Requires Two-Level Maintenance
F- 22 Opportunity To Use COTS Based
Graphic courtesy of
CWCECVITA 48
Radar Processor (RP)
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2020
ANSI / VITA 47-2005
In 1996, COTS not available to an open standard for Mil/Aero application environments
In 2005, an open standard approved for environmental, design and construction, safety, and quality requirements for COTS plug-in units intended for mobile applications
Keeps the advantages of open systems
Lower total ownership cost
Obsolescence protection, backward compatibility
Efficiency of common solutions across multiple applications
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The Maintenance Level Trade - Circa 1998
NoChange
FromBaseline
NoChange
FromBaseline
Option
Affordability Lethality/Survivability Supportability
DTC O&S Costs Weight Volume PerformanceIntegrity/Reliability
Ease ofMaintenance
Three LevelMaintenance
Two Plus LevelMaintenance
Two LevelMaintenance W/
Protection
One LevelMaintenance
Poor
Poor
Better (?)
Two LevelMaintenance
W/ KISSBaseline
Ease ofUpgrade
Lower
Lower
BaselineBaselineBaselineBaselineBaselineBaselineBaseline
6%Lower
6%Lower
3%Lower
3%Lower
5%Higher
Lower
Lower
Higher
MuchHigher
Higher
NoChange
FromBaseline
TBD%Higher
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
NoChange
FromBaseline
• LRU Removal At The O-Level.
• Card Removal At The I-Level.
• Card Repair At The Depot.
• Environmentally Protected Enclosure.
• Rugged Interface Connectors.
• Thermal Interface Is Not ContaminationSensitive.
• Cards Do Not Provide Protection AgainstESD/Handling Damage.
• LRU Removal At The O-Level.
• Ship LRU (Failed Card And Good Cards)To The Depot.
• Card Repair At The Depot.
• Same Hardware As For Three LevelMaintenance.
• Card (Line Replaceable Module or LRM)
Removal At The O-Level.
• Card/LRM Repair At The Depot.
• Environmentally Protected Enclosure (Installed).
• AKA - Integrated Electronics Rack (IER)
• Rugged IER Interface Connectors.
• LRM’s Provide ESD/Handling Protection.
• LRM/IER Connector/Thermal Interface Is Relatively Fragile.
•Three Level and Two Plus Level maintenance rejected due to high cost
•Two Level w/Protection rejected due to weight and volume increase
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Thermal Management Technologies
Active Transport Elements
Interfaces
LFT Cooling
Spray Cooling
Conduction Cooling
Passive Transport Elements
HRU
Global Solutions
Module Solutions
Liquid Metal Cooling Loop
Phase Change Fillers for
Liquid Loops
Custom and COTS Design Improvements
QDs
• Aluminum/Beryllium is being used in the F-22 CNI/EW power supply module.
• AlBe selected for CTE match to PWBmaterial, to minimize strain on solder jointsof large packages.
• Weight benefit of -0.065 pound per module.
• Cost upper of $400 per module.
• ~$6,200 per pound of weight saved.
• Health and process issues resolved.
Thermal Spreaders (Diamond,
etc.)
Heat Pipes
Custom and COTS Design Improvements
Vapor Chambers
Micro-Channels
Wedge Clamps
Heat Pipes
Wedge Clamps
Thermal Spreaders (Diamond,
etc.)
Refrigeration
Thermal Pads
Composite Chassis
Rarefied Air
PM
C/X
MC
Co
ve
r
PM
C/X
MC
Mo
du
le
Prim
ary
Sid
e C
ove
rw
ith E
jecto
rsW
ed
ge
Cla
mp
s
Co
mm
on
PC
BA
sse
mb
ly
Se
co
nd
ary
Sid
e C
ove
r
Thermoelectric
Spacecraft Radiator
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