Robles @ M&Eef 2008

1

Aerospace Thermal Management Challenges and Solutions, A Boeing Perspective

Jim RoblesPhn: 253-657-5663

Email: [email protected]

Reference Number: 07-045

22

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


33

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”


44

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

Approved for Public Release, Distribution Unlimited, PM FCS 26 JAN 2007, case 07-027

55

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


66

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


Functional

Densit

y

Power per Function

Functional

Densit

y

Power per Function

Thermal Density


Thermal Density


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


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


77

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


88

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


99

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



1010

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


Good500 to 800HighVery HighInternal Spray Cooled Custom

Medium



or external HRU


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


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


Good500 to 800LowInternal Spray Cooled COTS

Medium



or external HRU


or external HRU

MediumDirect Spray Cooled COTS

Medium

(25% Thermal Margin)

GoodHighest750BaselineBaselineLow$15k

(typical)

LowLFT Cooled COTS

Marginal


Good500 to 800HighVery HighInternal Spray Cooled Custom

Medium



or external HRU


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


Performance (Watts per

inch of pitch)

VolumeWeightO&S CostDesign To Cost (DTC)

Development Cost

SupportabilitySurvivability/LethalityAffordabilityOption


1111

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


1212

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.


1313

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


1414

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


1515

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


1616

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


1717

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


1818

Backup


1919

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)


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


2121

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


2222

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
