U.S. ARMY OPPPOSED PISTON ENGINE RESEARCH &...

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U.S. ARMY OPPPOSED PISTON

ENGINE RESEARCH & DEVELOPMENT

Bruce Brendle, Ph.D, PMP

US Army RDECOM - TARDEC

07 November 2018



22

Combat Powertrain Motivation

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M2A3 Bradley

Representative Area of Interest

NOGO: 6%, V50: 15 mph

Current Platform Plaftorm w/Adv Mobility

NOGO: 22%, V50: 10 mph

• Includes impacts of powertrain, track and suspension

• Red and Orange slower than Yellow and Green

• Significant reductions in NOGO terrain.

• Significant increases in average speed over the best 50% of the terrain.

Advanced Mobility Technology enables Increased terrain access at higher speeds

Current combat powertrain technology began development 50+ years ago, and is the basis still used today

Increasing Powertrain Power Density

Increasing Vehicle Power DemandsRequire Efficient Methods to Generate Power

~3 HP/ft3 ~6 HP/ft3

MoveSurviveCommunicatee-HVAC & CBRNShoot (e-turret)Anti-idle

e-Cooling Powertrain Electrified Protection

Export Power

Directed Energy (50 kW)

0

50

100

150

200

250

Electrical Power Required, (kW)

Typical Alternator

Delivering the next generation of combat vehicle powertrains and mobility solutions

1960 1970 1980 1990 2000

BFV

Abrams

Advanced Powertrain technology enables the Next Generation and lays the foundation for the Future Force

2010

M113A3

M88

2020• MOTS Powertrain Compartment Volume Increase ~ 56%• Resulting Increase in Vehicle Structure Weight ~ 3100 lbs.

Advanced Combat PowertrainEquivalent MOTS Powertrain



3

Current Combat Vehicle Engines

Main Battle Tank, M1 Abrams

– 1500 BHP gas turbine

– Very low heat rejection but high fuel consumption and high combustion air/exhaust flowrates

Infantry Fighting Vehicle, M2 Bradley

– 675 BHP diesel engine

– Medium heat rejection, Medium fuel consumption, Low engine power density on a per volume basis

Self Propelled Howitzer – Paladin

– 675 BHP diesel engine

– Medium heat rejection, Medium fuel

consumption, Low engine power density

Recovery Vehicle, M88 Hercules

– 1050 BHP air cooled diesel engine

– Low power density, Medium fuel consumption

There is a need for modernization across

these platforms that require minimal vehicle

level modifications



4

Ground Vehicle Powertrain Requirements

Max Forward / Reverse Tractive Effort to Weight. Tractive Effort: The force push or pull) that the powertrain can generate to move a vehicle.

1.0 TE/Wt is the maximum design point for combat vehicle operation at finite life

0.7 TE/Wt is the Design Cooling Point at 125F for the continuous operation of vehicles to achieve all the mobility requirements which includes 60% grade.

Cooling Fan Power Consumption Greater for armored combat vehicle than tactical vehicle due to air restriction thru ballistic grilles

Hotel Loads High electrical load mission payloads

Mission Profile Speed on grade, top speed, x-country speed, idle time, time spent powering electronic equipment, etc.

Environmental Conditions of -60F to +125F Engine power can decrease up to 25% depending on ambient temperatures

Air Filtration: 20 Hrs Life with Zero Visibility Dust at 60F

Altitude Performance Requirements

Fording / Flooded Engine Compartment Operation

JP-8 / DF-2 Fuels

Cold Start / Hot Restart Requirements

Ability to Recover a Like Vehicle

Tractive Effort (TE)

Rolling Resistance (RR)

Wind Resistance (WR)

Grade Resistance (GR)

Grade (G) %

Gross Vehicle Weight (GVW)



5

Industry and Army - Divergent PathsIM

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TIME

INDUSTRY FOCUS

Survivability

Mobility

Lethality

Low Volume

Emissions

CAFÉ

High Volume

Commercial Fuels (Gasoline, Diesel, Ethanol, Biodiesel etc.)

Single Battlefield Fuel (JP-8)

Off-Road, Challenging Terrain

Electrification

ARMY FOCUS

Alternative Fuels

Modified COTS Diesel Engines

Efficient Cross-Drive Transmissions

High Power Density,

Multi-fuel engines

Low heat rejection engines

Lightweight Track and Suspension

Fully Active Suspension

Tracked External Suspension Unit

Low Rolling Track Systems

High Voltage Li-Ion Batteries

High Voltage In-line Generators

ULSD Auxiliary Power Units High Temperature

Power Electronics

Emissions Improvements

Hybrid Electric Vehicles

Battery Electric Vehicles

Engine Improvements

Electric Drive TechnologyFuel Cell

Vehicles

Multi Speed Transmissions



66


Ele

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kW

M2A3 Bradley


NOGO: 6%, V50: 15 mph


NOGO: 22%, V50: 10 mph









~3 HP/ft3 ~6 HP/ft3



Export Power


0

50

100

150

200

250


Typical Alternator


1960 1970 1980 1990 2000

BFV

Abrams


2010

M113A3

M88





7

Power Density (PD) = sprocket (wheel) power / total propulsion system volume [bhp/ft3]

Power density of complete propulsion system:

Engine

Drivetrain (including steering and brakes for tracked vehicle)

Air filtration system

Cooling system

Inlet and exhaust ducting

Propulsion control systems

Accessory drive interfaces

Batteries (for propulsion), wiring harnesses

Fuel tanks and plumbing

Final drives

Maintenance access and clearances

Current Combat Vehicle Power Density Values

M1 Abrams 3.3 bhp/ft3

M2 Bradley 2.9 bhp/ft3

Future combat vehicle goal 6.0 bhp/ft3

Combat Vehicle Propulsion System

Power Density Is Greatest Need

Thermal Management ProblemRestricted vehicle space allocations magnify powerpack cooling problems: Limited space for heat exchangers and ballistic

grilles Poor fan inlet and outlet conditions (lower efficiency)

Parasitic fan power scales with the cube of heat

rejection

25% reduction of heat rejection leads to over a 50%

reduction in parasitic fan power Example: 1000 BHP powerpack requires 200 BHP

fan power to cool with a traditional engine; use of

low heat rejection engine requires 100 BHP and

thus puts 100 BHP bacl at the sprocket



88

Ele

ctr

ica

l P

ow

er,

kW

M2A3 Bradley


NOGO: 6%, V50: 15 mph


NOGO: 22%, V50: 10 mph









~3 HP/ft3 ~6 HP/ft3



Export Power


0

50

100

150

200

250


Typical Alternator


1960 1970 1980 1990 2000

BFV

Abrams


2010

M113A3

M88






9

Combat Vehicle Electrification Demands

Improved System Efficiency Advanced CapabilitiesAdvanced Systems

TransmissionISGMobility Output

Engine

Inverter

Cooling Fan Inverter

Vehicle-to-Grid & V2V

DC-DC

Low Voltage

Batteries

Existing Automotive

Loads

Energy Weapons System

Legend: Existing Architecture28VDC600VDC

Mechanical200 - 600VAC

Powertrain Cooling Sys

Vehicle Controller

Electric Main Cooling Fan

HVPC600 VDC

Steering Pump Controller

Steering Pump Motor

HVAC Inverter

HVAC System

HVAC Compressor

Steering System

Wireless Energy Beaming

Non-Lethal Energy Weapons

High Voltage Energy Storage Silent & Enhanced Mobility

Non-Lethal Crowd Disbursement

Sustained UGV/UAV operation

C-RAM and C-UAV

High Power Jamming IED & Other defeat

Electronic Armor Lighter Weight Armor

High Power Comms Improved communications

AC and VAC = Alternating CurrentC-RAM = Counter Rocket, Artillery and MortarC-UAV = Counter Unmanned Arial VehicleDC = Direct CurrentDC-DC = HV/LV DC Power Conversion

HV = High VoltageHVAC = Heating Ventilation and CoolingHVPC = High Voltage Power ControlISG = Integrated Starter GeneratorLV = Low Voltage (24 VDC)

UAV = Unmanned Arial VehicleUGV = Unmanned Ground VehicleVDC = Volts Direct CurrentV2G = Vehicle to GridV2V = Vehicle to Vehicle

Expeditionary Power

Planned/Future Development

Intelligent Engine Start/Stop

600 VDC24 VDC

EM Gun Long range multi-use weapon



10

Vehicle Mobility Performance Characteristics

0

25

50

75

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125

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0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Spro

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Po

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HP

Vehicle Speed MPH

Sprocket Power vs. Speed: Current Powertain vs. ACE 1000 hp : All @125Deg F Day, 40, 45, & 50Tons & Same Cooling System Size

ACE 1000 hp, 28 kW

Current 675 hp Engine, 28 kW

ACE 1000 hp, 160 kW

Highlights the need for Power Dense, Low Heat Rejection Engine that Fits within an existing combatsystem to provide the additional on-board electrical power demands to maintain mobility

Existing military propulsion systems lack the powerdensity and efficiencies necessary to provide leapahead capabilities for combat vehicles.

Fuel Efficient Engine Alone is Not SufficientNeed a complete efficient and power dense propulsion system that provides low heat rejection to minimize thermal burden

Engine Transmission Air Filtration System (Low Restriction) Cooling System (Low Fan Power) Inlet and Exhaust Ducting (Low Restriction)

Propulsion Control System Accessory Drives Batteries and Wiring Harnesses Fuel Tanks and Plumbing (Sized for Mission Requirement) Drive Trains



1111

Ele

ctr

ica

l P

ow

er,

kW

M2A3 Bradley


NOGO: 6%, V50: 15 mph


NOGO: 22%, V50: 10 mph









~3 HP/ft3 ~6 HP/ft3



Export Power


0

50

100

150

200

250


Typical Alternator


1960 1970 1980 1990 2000

BFV

Abrams


2010

M113A3

M88






12

Focus on low heat rejection engine technology based on propulsion system power density considerations

1960’s to 2000’s emphasized advanced four stroke diesel engine technology that pushed engine power

density with low heat rejection

Thermal barrier coatings/ceramic engine subcomponents

High pressure ratio turbocharging

High temperature lubricants

Variable compression ratio

Very high rated speed

Minimal charge air cooling

1982 – 1993 Diesel Advanced Integrated Propulsion System (AIPS) projected propulsion system power

density of 5.8 BHP/ft3 with a 1500 hp engine for a future tank application

Oil cooled engine with 300+ F sump temperature

Demonstrated overall engine specific heat rejection below 0.5 kW/kW

Much attention paid to eliminate powerpack unused volume

Program cancelled by the Army prior to the final leg of development

2000’s – Future Combat Systems (FCS)

20 ton initial vehicle target application with propulsion system power density target to exceed 5 BHP/ft3

Two diesel engine candidates

Modified commercial pickup truck engine (unsuccessful)

Specially high speed, high power density military specialty diesel

Advent of MTU 890 series family of engines

Army Advanced Diesel Engine Developments



13

Mid 2000’s consideration given to Opposed Piston, two-stroke engine technology based on inherent low heat

rejection and potential packaging advantages over conventional V-geometry four stroke combat engines

Kharkov 6TD-2 Engine Test & Evaluation (1999-2002)

Engine Characteristics

Six cylinder

Super charged and turbo compounded

Rated power: 1200 BHP - Peak torque: 2385 ft-lb

Displacement: 16 L with Bore x Stroke: 120 x 120 mm

Major Conclusions

Very low heat rejection with a advantageous packaging volume

Excessive smoke

Questionable durability

Poor fuel consumption at part-load

Opposed Piston Opposed Cylinder (OPOC) (2006 – 2012)

Based on modified DARPA A160 Hummingbird UAV hardware developed during the 2003 to 2007 timeframe

Army program targets

320 BHP at sea level

Specific heat rejection target 0.42 kW/kW

Pass 50 hour AEP-5 NATO test

Conclusions

Failed to pass 50 hour AEP-5 NATO test due to a variety of mechanical issues

Did not attain heat rejection or power density targets

Army Advanced Diesel Engine Developments

Opposed Piston Technology



14

Power & Mobility Technology Development

Power Dense, Common, Modular Engines• Increased Power Density• Increased Efficiency (> 48%)• Decreased Heat Rejection (≤ 20 BTU/hp-min)• Common Engine Components (Family of Engines)

Adaptable, Military Specific Transmissions• Advanced Multi-Speed Transmissions• Adaptable to a wide range of engine input speeds• Flexible design configuration and packaging• High efficiency geared steering system• > 90% efficiency in all gears

Efficient Thermal Management• Improved vehicle efficiencies• Increase Propulsion Power Density, more sprocket power• Develop and integrate high efficiency components• Increased fidelity of system level thermal management

analysis and optimization

Controls Development & Vehicle

Electrification• Developing a controller with industry partner that will meet

future research needs by using the state of the art components, incorporating greatly increased processing power, and supporting multiple new communication protocols

• Increased onboard vehicle power to 100-160 kW

# of Modules

Ho

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po

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Medium

Combat

Heavy

Combat

Power Electronics

(DC-DC, Export Power

Optimized

Powertrain Controls

High Voltage

Architecture

Integrated Starter Generator

Advanced Heat

Exchanger

Pack

Electrical Fan

DriveAdvanced Fan

Advanced

Modular Battery

1

4



15

Advanced Combat Engine Program Initiatives

Develop and Demonstrate the State-Of-The-Art Advanced Combat Engine & Technologies to Provide the Combat Vehicles with Increased Mobility and On-Board Power

Scalable and Modular Engine Technology (common bore and stroke).

Size: Increased Package Power Density

Shape Optimized for Bay Space Claim

Horizontal or Vertical

Weight: Low Installed Weight

More Mobility, Armor and Payload

Performance: Increased Power and Mobility

Increased Tractive Effort Availability

Improved Fuel Tolerance

Improved Range thru Fuel Efficiency

Cooling: Reduce Specific Heat Rejection to the Vehicle

Reduce Cooling System Power Needs

23”

23”

43”

43”41”

49”

In-Line 6

(1200 – 1500 hp)

23”

43”63”

In-Line 4

(800 – 1000 hp)

In-Line 3

(600 – 750 hp)



16

FY15 FY16 FY17 FY18 FY19 FY20 FY21 FY22 FY23

Advanced Combat Engine (ACE) Roadmap

16

Single Cylinder Engine Development System Level Integration and DemonstrationMulti-Cylinder Engine Development

Cummins/Achates ACE 1000

Alternative Engine

Advanced Mobility Experimental Prototype AMEPMatures APD Integrated Systems, Adds Intake and Exhaust Systems, Develops Controls for Dynamic Testing in Bradley vehicle

Engine Path to Production

Achates/Cummins

5 9

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Advanced Powertrain Demonstrator APDIntegrates Engine with Transmission, Thermal, Controls, ISG, Battery in a Bradley Chassis

76



17

2010 2015 2020

Army OP Engine internal study confirms inherent advantage

NGCE

Next Generation Combat Engine [NGCE]• Industry competition selection on next

generation engine technology • 71 hp per cylinder• 225 hp Proof of Principal technology

demonstrator on dyno at TARDEC• Significantly overachieved objective

ACE Accomplishments

ACE SCE

ACE MCE

Measure Program Objectives

Test Data Results

Power 200-300 hp 225 hp @ 2400 rpm

Torque > 500 lb-ft525 lb-ft @ 1600

rpmFuel Consumption

< 0.36 lb/hp-hr ~ 0.34 lb/hp-hr

Heat Rejection < 0.71 kW/kW 0.64 kW/kW

Power per cylinder

> 70 hp/cylinder 70.3 hp/cylinder


Test Data Results

Power 250 hp 251 hpTorque > 500 lb-ft 597 lb-ftFuel Consumption

< 0.32 lb/hp-hr ~ 0.31 lb/hp-hr

Heat Rejection < 0.45 kW/kW 0.506 kW/kWPower per cylinder

> 250 hp/cylinder 250 hp/cylinder


Power 1000 hpTorque > 2000 lb-ft

Fuel Consumption < 0.32 lb/hp-hr

Heat Rejection < 0.45 kW/kWPower per cylinder

> 250 hp/cylinder

ACE Single Cylinder Engine [SCE] Feb 2015 - Awarded 2 Contracts Competing engine development

and demonstration in 24 months

ACE Multi Cylinder Engine [MCE] July 2017 – Awarded ACE MCE contract July 2018 – Completion of First Engine Build Dec 2019 – Initial Engine Test & Performance

Completion June 2019 – Achieve TRL6 with 50 hr NATO test Aug 2019 – Deliver Engine to TARDEC for testing

& integration

Leveraging over $150M of industry investment in OP2S engine technology since 2004 to provide combat vehicles with increased mobility and on-board power through scalable and modular engine technology.

U.S. ARMY OPPPOSED PISTON ENGINE RESEARCH &...

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