55 GVSETS 2016 SCOPE Heat Rejection to Power Measurement and Simulation, Kacynski

This document consists of general capabilities information that is not defined as
controlled technical data under ITAR Part 120.10 or EAR Part 772.
Single Crankshaft Opposed Piston Heat Rejection Measurement and
Simulation on High Power Density Engines for Future Ground Combat
Vehicle Power Pack Configurations
22 July 2016
Ken Kacynski, PhD
Engineering Fellow
L-3 Combat Propulsion Systems
Ken.Kacynski@L-3com.com
S. Arnie Johnson
Chief Technology Officer
Arnie.Johnson@L-3com.com
Ming Huo
Combustion Analyst
Ecomotors
ming.huo@ecomotors.com
John Yancone
Chief Engineer
John.Yancone@L-3com.com
Chris Meszaros
Engineering Test Manager
Ecomotors
chris.meszaros@ecomotors.com

AGENDA
• Single Crankshaft Opposed Piston Engine (SCOPE):
– Heat Rejection to Power Ratio Advantages
– Commercial Engine Configuration Description
– Test Description
– Measured Values
• Heat Generation
• Power
• Militarization of the SCOPE Configuration
– Barrel Temperature Optimization
– Ceramic Insert Piston Crown
– E-Boost Supercharger w/Variable Geometry Turbocharger
• Conclusions and Recommendations
22 July 2016 2

Background:
Engine Heat Transfer-to-Power Criteria
• Critical Engine Parameter for Military Applications
– Approximately 20 % of Engine Power Consumed by Cooling Fans
– Cooling System Volume Becomes an Increasingly Critical
Consideration
22 July 2016 3
Nearly all Reductions in Power-pack Volume are the Result of
Reductions in Engine Size and Engine Improvements
Volume(ft3)
Engine Cooling
System
Transmission Air
Induction
Batteries Fuel UnusableAir Intake
& Exhaust
1000 Hp Power-pack
Legacy Configuration
‘Next Generation’ Configuration

Single Crankshaft Opposed Piston Engine -
Heat Transfer to Power Advantages
• 2- Stroke Engines Have an Inherent Advantage
– 2 Stroke Engines:
• ½ of the time heat is being transferred with no power generated
– 4 Stroke Engines
• ¾ of the time heat is being transferred with no power generated
• 2-Stroke Opposed Piston Engines Have Additional
Advantages
– Surface Area/Volume of Opposed Pistons is significantly lower than
exist in inline or with V shaped engines (~30% lower)
• 2-Stroke Single Crankshaft Opposed Piston Engines Offer
Even Further Advantages
– Reduced loads on crankshaft bearings
– Capable of higher speed operation
22 July 2016 4
Single Crankshaft Opposed Piston Engine are the Configuration
of Choice for Low Heat Generation-to-Power Ratios

SCOPE Configuration
Description
22 July 2016 5
(2)
Commercial
Engine
(125 kW) –
Entering
Production
in 2017
• SCOPE Scheduled for Commercial Production in 2017
• Currently Undergoing Production Configuration Validation

Test Description – 2 Cylinder
Commercial SCOPE Engine
Measurement of Heat Generation-to-Power Ratio:
22 July 2016 6
Fuel System
Inlet Pressure
Inlet Temperature
Flow Rate
Combustion Air Intake System
Intake Air Pressure
Intake Air Temperature
Air Flow
Supercharger Cooler - Combustion Air Temperature and
Pressure (Upstream and Downstream)
Compressor Aftercooler -Combustion Air Temperature and
Pressure (Upstream and Downstream of cooler)
Exhaust Gas Before Turbocharger - Pressure and Temperature
Exhaust Gas After Turbocharger - Pressure and Temperature
Oil Lubrication System
Oil flow rate
Oil temperature and pressure entering and exiting oil cooler
Cooling System
Coolant flow rate to cylinder #1
Coolant flow rate to cylinder #2
Coolant temperature and pressure entering coolers (cylinders
#1 and #2 separately cooled)
Data Taken: 19 July 2016
Location: Katech Engines
Engine Output Power
Measured with a water brake
dynamometer
Supercharger Power Consumption Measured with a torque meter
Measured power produced or consumed

Commercial SCOPE
Configuration Results
22 July 2016 7
‘Configuration Baseline’ Heat-to-Power Ratio of 0.88 is a Good
Starting Point for Product ‘Militarization’
Heat Generation
Energy loss to coolant [kW] 27.37 26.4%
Energy loss to oil [kW] 32.31 31.3%
Energy loss to aftercooler [kW] 35.42 34.3%
Energy loss to intermediate air
cooler [kW]
8.26 8 %
Total [kW] 103.36 100 %
Power
Generation/Consumption
Brake Power [kW] 127.2
Supercharger Power [kW] 9.4
Net Crankshaft Power [kW] 117.8
HR-BP ratio 0.88

• Heat-to-Power Ratio Requirement is 0.45.
• Ideas to achieve requirement:
– Optimize the surface temperature of the cylinder barrel
– Increase the surface temperature of the piston crown
– Redesign the air boost system (eliminate the need
for supercharging at high power,
increase intake air temperature)
Additional Ideas Adding ‘Margin’
– Improved combustion efficiency (to be obtained
primarily through commercial product development)
– Waste heat recovery (option)
22 July 2016 8
A ‘Militarized’ SCOPE configuration can be created with 3
modest design changes to the commercial SCOPE
SCOPE Militarization

Optimize Barrel Temperature -
Concept
• Analysis shows the cooling flow optimization can raise barrel wall temperature
and reduce heat transfer
• Current SCOPE engine operates at temperatures well below design limits (500K
where piston rings make contact)
22 July 2016 9
Barrel hot side wall temperature
predictions for the commercial
SCOPE engine
Barrel hot side wall temperature
predictions for the militarized
SCOPE engine
(K) (K)

Optimize Barrel Temperature -
Results
Heat transfer comparisons
from the barrel of the engine
22 July 2016 10
Commercial
SCOPE with
water
cooling
Militarized SCOPE
with engine oil
cooling of the
cylinder barrel
Exhaust Port
Region
8.7 kW 6.1 kW
Top Dead
Center Region
9.5 kW 5.9 kW
Outer Piston
Travel Region
6.0 kW 4.5 kW
Inner Piston
Travel Region
3.2 kW 2.0 kW
Total Heat
Transfer to the
Barrel
27.4 kW 18.5 kW
Commercial
SCOPE
Engine
Militarized
SCOPE with
optimized
barrel
temperature
%
Change
Combustion Air
Cooling
43.7 kW 43.7 kW -
Oil Lubrication
System Cooling
32.3 kW 32.3 kW -
Barrel Cooling 27.4 kW 18.5 kW 32 %
Total Heat
Generated
103.4 kW 94.5 kW 9 %
Net Power
Generated
117.8 kW 117.8 kW -
Heat Generation to
Power Ratio 0.88 0.80 9 %
Heat-to-Power ratio comparison
Oil Cooling of the Barrel Liner Projected to Reduce
the Heat-to-Power Ratio by 9 %

Increase Piston Crown
Temperature - Concept
• Most of the heat rejected to oil is from piston cooling and represents 30% of total
heat generated.
• A ceramic insert in the piston crown can substantially reduce heat transfer.
22 July 2016 11
Piston surface temperature predictions
for the commercial SCOPE engine
Piston surface temperature predictions for
the militarized SCOPE engine
(using a ceramic insert)

Heat transfer and heat-to-power ratio comparisons
22 July 2016 12
Commercial
Scope Engine
SCOPE Engine with
ceramic inserts
% Change
Air Induction System Cooling 43.7 kW 43.7 kW -
Oil Lubrication System Cooling 32.3 kW 8.8 kW 73%
Ethylene Glycol/Water Cooling System 27.4 kW 27.4 kW -
Total Heat Generated 103.4 kW 79.9 kW 23%
Net Power Generated 117.8 kW 117.8 kW -
Heat Generation to Power Ratio 0.88 0.68 23 %
Ceramic Inserts on the Piston Crown Projected to
Reduce the Heat-to-Power Ratio by 23 %
Increase Piston Crown
Temperature - Results

Redesign the Air Boost
System- Concept
• Commercial baseline uses both supercharging and turbocharging
• Air boosting technologies like Borg Warners e-boost/Variable Geometry
Turbocharger (VGT) system can serve to replace the supercharger.
• Because emission regulations do not apply, charge air temperatures can be
increased from 60 C to ~ 120 C.
22 July 2016 13

Redesign the Air Boost
System - Results
Heat transfer and heat-to-power ratio comparisons
22 July 2016 14
Commercial Scope
Engine
SCOPE Engine
with redesigned
air boost
system
% Change
Air Induction System
Cooling
43.7 kW 30 kW 31 %
Oil Lubrication System
Cooling
32.3 kW 32.3 kW -
Ethylene Glycol/Water
Cooling System
27.4 kW 27.4 kW -
Total Heat Generated 103.4 kW 89.7 kW 13 %
Gross Engine Power 127.2 127.2 kW -
Supercharger Power 9.4 0 kW 100 %
Net Power Generated 117.8 kW 127.2 kW 8 %
Heat Generation to Power
Ratio
0.88 0.71 19 %
Improvements to the Air Boost System Reduce the Heat-to-Power Ratio
of the SCOPE engine by 19 %

Summary
22 July 2016 15
Commercial Scope
Engine
SCOPE Engine with
optimized barrel
design, ceramic
piston crown, and
redesigned air boost
system
% Change
Air Induction System Cooling 43.7 kW 30 kW 31 %
Oil Lubrication System Cooling 32.3 kW 8.8 kW 73 %
Ethylene Glycol/Water Cooling
System
27.4 kW 18.5 kW 32 %
Total Heat Generated 103.4 kW 57.3 45 %
Gross Engine Power 127.2 127.2 kW -
Supercharger Power 9.4 0 kW 100 %
Net Power Generated 117.8 kW 127.2 kW 8 %
Heat Generation to Power Ratio 0.88 0.45 48 %
SCOPE Engine Projected to satisfy Heat-to-Power Requirement (0.45)

Conclusions and
Recommendations
• Conclusions:
– A heat-to-power ratio of 0.45 appears feasible using the SCOPE engine design.
– Analysis and test results indicate that a 45 % heat reduction can be achieved through the
following modifications of the commercial SCOPE engine:
• Optimization of cylinder barrel temperature
• Usage of a ceramic insert on the crown of the piston
• Redesign of the air boost system
– Analysis and test results indicate that an 8 % net power increase can be achieved by
redesign of the air boost system.
• Recommendations:
– Continue to leverage advancements from the commercial SCOPE product for military
applications.
– Complete engine testing (performance and reliability) to verify design changes identified
in this presentation.
– Consider the SCOPE architecture for future military engine development programs.
22 July 2016 16
SCOPE Can Achieve the Military Heat Rejection Target

55 GVSETS 2016 SCOPE Heat Rejection to Power Measurement and Simulation, Kacynski

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