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CALSTART Webinar Series: Achates Power on Opposed Piston Two Stroke Engines 4-24-2013
 

CALSTART Webinar Series: Achates Power on Opposed Piston Two Stroke Engines 4-24-2013

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Achates Power on Opposed Piston Two Stroke Engines 4-24-2013 ...

Achates Power on Opposed Piston Two Stroke Engines 4-24-2013
Opposed-piston, two-stroke (OP2S) engines have a long and successful history that dates back to the late 1800s. Used in ground, marine and aviation applications, these engines are known for their record-setting combination of power density and fuel efficiency. However, despite two-stroke powertrain advancements, the engines suffered from high NOx and soot, along with poor oil control. Therefore, their use in on-road applications ceased with the advent of global emissions regulations. Yet with the technologies now available, there has never been a better time to modernize the OP2S.

The CALSTART Achates Power-hosted webinar featured John Koszewnik, Chief Technical Officer, Achates Power who provided an historical overview of opposed-piston engines and their inherent thermal efficiency benefits. Mr. Koszewnik also introduced attendees to measured results from an Achates Power OP2S engine which suggest that the technology can produce an economically and environmentally sustainable powertrain that can fit existing vehicles, be manufactured in today's engine plants, and run on a variety of fuels including diesel and natural gas.

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  • So here’s our game changer.Like so many other “new ideas”, ours is an old and proven idea that needed to be dusted off, re-invented, modernized. Problems and challenges that we, we the industry, thought were insurmountable, had to be addressed. That’s what we’ve been up to since 2004. The authors of this 2010 book had a similar good idea. We appreciate their affirmation of the quest our founder initiated in 1998 and which became Achates Power in 2004.
  • Opposed piston engines are not new. The first two stroke opposed engine in fact dates back to the late 1800’s. In fact, the many design iterations of opposed piston engines have been captured in a recent SAE publication by JP Pirault and Martin Flint, from which I borrowed this illustration.The first thing you’ll immediately notice about opposed piston engines is that there is no cylinder head. Instead, they essentially look like two bottom halves of a conventional engine somehow “stuck together”. So let me explain quickly how they operate because it is not obvious.-- When the pistons come together, fuel is directly injected and as the case with every compression ignition engine, it autoignites.-- This then creates the expansion event during which time force on each piston is translated by the crank-slider mechanism into torque. A geartrain connecting together both cranks then transmits this torque to the engine’s output shaft.-- As the distance between the pistons increase, intake and exhaust ports (essentially holes in the cylinder liner) are exposed… and part of the combustion gas is expelled. A crank drive supercharger provides the boost pressure or “muscle” to drive the exhaust gases out and replace it with fresh air. This process is called scavenging.-- When the ports close (with the exhaust closing a bit earlier than the intake), there is a supercharging or pressure building event in the cylinder and this then begins the compression stroke which brings the pistons together, thereby increasing cylinder pressure.One of the most well known compression ignition two-stroke opposed piston engines was the Junker’s Jumo, which set world records for fuel efficiency.Unfortunately, it suffered from durability and poor oil consumption… so much so that when women in Germany would hear the distinctive sound of a Jumo Junkers plane overhead, they would run outside to remove their clean clothes from their clotheslines.
  • A quick re-cap of how this works:Reducing the combustion chambers surface area to volume ratio reduces heat losses, increases efficiency.Leaner is better. We run leaner than the best diesels.Shorter and better timed combustion is more efficient. Ours is. And we match pressure rise rates of benchmark engines, as well as engine out emissions.Efficient breathing… no throttling, ports that breath more freely than poppet valves, efficient uni-flow scavenging, especially at part loads…
  • So the first questions you may ask are:-- What virtues do all opposed piston engines have in common.. . And why?, and-- What special features on the Achates engine set it apart from other opposed piston engines?First, let’s discuss fuel efficiency.As discussed earlier, all opposed piston engines have no cylinder head.-- On non-opposed-piston engines, you need a cylinder head with poppet valves for the gas exchange. An opposed piston engine simply moves gases in and out of the combustion chamber through ports in the cylinder liner.-- Each unit of diesel fuel has a given energy value.-- When combusted, that energy goes into either work or heat. That heat can go into coolant system or out the exhaust.-- When you have a cylinder head, you add a heat path… more heat to coolant… and that reduces the work transmitted into the engine output shaft.-- Without that heat path on an opposed piston engine, an increased percentage of fuel energy goes to the output shaft and that means increased fuel economy.Secondly, in a conventional four-stroke, there is a pumping loop… essentially you have half the strokes (an exhaust followed by an intake stroke) used to evacuate the combustion gas from the cylinder.-- To achieve low NOx in a conventional four-stroke engine, this exhaust gas is then cooled and recirculated back into the intake.-- In our case, when we want more external recirculated exhaust gases, we can simply reduce the boost pressure from the supercharger. That is, leave the combustion gases only partially scavenged.-- And yes, we do have an external recirculated exhaust gas loop on our engine as well, but it is there only to manage trapped temperatures in the cylinder.-- This is an advantage for all two stroke engines.Thirdly, our Achates opposed piston engine also has a relatively long stroke-to-bore ratio… notably between 2.2 and 2.6 depending upon the application… which reduces its surface area to volume relationship versus other engines.-- This also reduces the percentage energy from the fuel that finds a heat transfer path to coolant.-- Unfortunately, you can’t do this with a non-opposed-piston or cylinder head engine, because with such a stroke-to-bore ratio, you would end up with a high mean piston speed, small bore diameter, small valves… and therefore the engine can’t breath well enough.Also unique to the Achates Power two-stroke, we have done much work using the latest computed aided engineering tools to get the combustion right. By this, we mean getting the right combination of cylinder liner ports, injector spray patterns, piston bowl shapes, and calibration to get a very rapid combustion with the right timing while maintaining an unacceptable rate of pressure rise.-- Some not familiar with our work have made statements about not being able to “make good combustion take place in a pancake shaped combustion chamber”.-- To this, I would just say “we don’t do it in a pancake”… and with the freedom we have with two pistons coming together and two opposed injectors, we actually have shown opposed piston engine architectures to be a combustion advantage.-- More precisely, we have been able to get large λ (or air/fuel ratio) = 1 isosurfaces at the point of autoignition… with the right combination of tumble and swirl charge motion to ensure rapid propagation of the diffusion flame.-- That plus the fact that we expand more rapidly (1/V dV/dT) than with a single piston… so we don’t have quite the same concern with maximum rate of pressure rise… which is a limiting factor due to noise.Our engine also offers the advantage of lower NOx. -- Torque is a function of BMEP (or brake mean effective pressure) times displacement. -- On the lower left, the x-axis is engine displacement volume and the y-axis is BMEP or (brake mean effective pressure).-- Keep in mind that BMEP is related to peak cylinder pressure and incylinder temperatures… and that nitrous oxide generation is a function of high pressure and high temperature.-- The blue line shows possible combinations of BMEP and displacement that result in equivalent torque output to a medium duty four-stroke diesel of roughly 6-1/2 liters of displacement. -- Since a 2 stroke fires on every crank revolution (compared with a 4 stroke that fires every other crank revolution), we can achieve the same power at either 1.) the same 4-stroke BMEP and half the displacement or 2 2.) the same 4-stroke displacement and half the BMEP.-- In execution, we have chosen a “sweet spot” for fuel efficiency and package somewhere in the middle. -- The result? Lower BMEP, lower peak cylinder pressures, lower temperatures  less NOx-- And yes, we see some increased friction from going in at a larger displacement than running with the 4 stroke BMEP, but we more than regain the friction penalty by having to pump less exhaust gas during our scavenging.Lastly, why do have lower cost and weight? Well the biggest contributor is the lack of cylinder head with all its valvetrain, camshaft, lubrication, and cooling components.
  • And our advantages are demonstrated, documented and highly scrutinized…About 10% better at the best pointAbout 20% better on a cycle average basisWe are approaching 50% BTE on a very small engine and without any exotic or expensive technologies, such as waste heat recovery.And that’s versus the very best diesel engines with comparable performance on all other attributes, torque, hp, emissions, noise…
  • Considering therefore our definition of game changing technology, the OP2S fits the definition:Big improvementLess costNo back sliding on other attributesCompatible with conventional engine improvement roadmap

CALSTART Webinar Series: Achates Power on Opposed Piston Two Stroke Engines 4-24-2013 CALSTART Webinar Series: Achates Power on Opposed Piston Two Stroke Engines 4-24-2013 Presentation Transcript

  • Meeting Future FuelEfficiency and EmissionsRegulations with theOpposed-Piston EngineJohn KoszewnikChief Technical OfficerApril 24, 2013
  • 1©2013Achates Power, Inc. All rights reserved.Key Questions To Be Addressed Today Who is Achates Power? Why can an opposed-piston, two-stroke diesel engine be more fuelefficient than a four-stroke diesel? Why can an opposed-piston, two-stroke diesel engine have superioremissions performance? What has been demonstrated via dynamometer testing? How are the historical challenges of opposed-piston, two-strokediesels addressed? How does this compare with four-stroke fuel efficiency and emissionimprovement actions? How should you validate a game-changing, disruptive technology?
  • 2©2013Achates Power, Inc. All rights reserved.Key Questions To Be Addressed Today Who is Achates Power? Why can an opposed-piston, two-stroke diesel engine be more fuelefficient than a four-stroke diesel? Why can an opposed-piston, two-stroke diesel engine have superioremissions performance? What has been demonstrated via dynamometer testing? How are the historical challenges of opposed-piston, two-strokediesels addressed? How does this compare with four-stroke fuel efficiency and emissionimprovement actions? How should you validate a game-changing, disruptive technology?
  • 3©2013Achates Power, Inc. All rights reserved.Achates PowerA company formed to design and develop clean, moreefficient, lower cost engines Founded in 2004 Well supported, technically and financially Design and development of multiple variationsof opposed-piston, two-stroke diesel engines Demonstrated, validated results, 4,000+ testhours on several engine generations State-of-the-art facilities and analytical tools Highly capable teamAn intellectual property company We rely on existing OEMs to produce our engines for theirvehicles. Our revenue comes from a combination of professionalservices and royalties.
  • 4©2013Achates Power, Inc. All rights reserved.Modernizing an Old Idea“The simplicity and compactness of the OPengine, combined with its potential for brakefuel efficiency in excess of 45%, and lowemissions suggest this is a power unit thatneeds re-evaluation.”“Weight and cost comparisons indicate thatthe two-stroke OP engine could beapproximately 34% lighter than the equivalentperformance four-stroke and cost 12% less.Source:JP Pirault, M. Flint, Opposed Piston Engines – Evolution, Use, andFuture Applications; SAE International 2009
  • 5©2013Achates Power, Inc. All rights reserved.Opposed-Piston, Two-Stroke Engine OperationSource: JP Pirault, M. Flint, Opposed Piston Engine: Evolution, Use, and Future Applications, SAE International 2009
  • 6©2013Achates Power, Inc. All rights reserved.Key Questions To Be Addressed Today Who is Achates Power? Why can an opposed-piston, two-stroke diesel engine be more fuelefficient than a four-stroke diesel? Why can an opposed-piston, two-stroke diesel engine have superioremissions performance? What has been demonstrated via dynamometer testing? How are the historical challenges of opposed-piston, two-strokediesels addressed? How does this compare with four-stroke fuel efficiency and emissionimprovement actions? How should you validate a game-changing, disruptive technology?
  • 7©2013Achates Power, Inc. All rights reserved.Engine Architectures with Comparable FrictionIVC IPCIPCEngine 4SCylinders 6Trapped Volume/Cylinder 1.0 LBore 102.6 mmTotal Stroke 112.9 mmStroke per Piston 112.9 mmStroke/Bore Ratio 1.1Trapped Comp. Ratio 15:1Intake Valve Closure 180 bTDCEngine OP2SCylinders 3Trapped Volume/Cylinder 1.6 LBore 102.6 mmTotal Stroke 224.2 mmStroke per Piston 112.9 mmStroke/Bore Ratio 2.2Trapped Comp. Ratio 15:1Intake Port Closure 120 bTDCOpposed-Piston, Two-Stroke(OP2S) EngineFour-Stroke(4S) Engine
  • 8©2013Achates Power, Inc. All rights reserved.Quantifying the Surface Area / Volume Ratio AdvantageIVC IPCIPCSurface Area (mm2) 4.05*104Volume (TDC) (mm3) 1.43*105Surface area / Volume(mm-1) 0.28Opposed-Piston, Two-Stroke(OP2S) EngineFour-Stroke(4S) EngineSurface Area (mm2) 2.07*104Volume (TDC) (mm3) 1.14*105Surface area / Volume(mm-1) 0.18-49%-20%-36%This surface area-to-volume advantage minimizes heat losses…i.e.,more energy goes into work and improves fuel efficiency.This comparison is conservative as the cylinder head of a four-stroketypically runs 80-100o C less than the cylinder liner.
  • 9©2013Achates Power, Inc. All rights reserved.Fuel Injection System Unique and proprietary injector nozzle design and spray patternprovides interdigitated fuel plumes with larger λ=1 isosurfaces Dual injectors per cylinder provide multiple injection events,appropriate flow rates and mid-cylinder penetrationPatented Achates Power Combustion SystemPort and Manifold Design Port design is optimized to provide optimal blow down, uniflowscavenging, supercharging and swirl characteristicsPiston Bowl Shape Proprietary piston crown designs combine swirl with tumblemotion during compression Provides excellent mixing, air utilization and charge motion forrapid diffusion and flame propagation Ellipsoidal shape of combustion chamber guarantees airentrainment into spray of plumes coming from two sides intocenter of cylinder Minimal flame-wall interaction during combustionResult: Short burn duration, earlier auto-ignition timing, minimal heat transfer losses
  • 10©2013Achates Power, Inc. All rights reserved.Heat Release Rates-1-0.8-0.6-0.4-0.200.20.40.60.8101002003004005006007008009001000MassBurntFractionHeatReleaseRateCrank AngleTypical 4S EngineMeasured OP2S Engine
  • 11©2013Achates Power, Inc. All rights reserved.Why Is an OP2S Diesel More Fuel Efficient?Versus four-stroke engines 30+% lower surface area-to-volume ratio No heat losses to cylinder head Shorter burn duration Earlier combustion phasing withoutexceeding peak cylinder pressure Leaner combustion -- i.e., favorablespecific heat of air/fuel mixture Reduced pumping losses at low loadsleads to flat fuel map – can leaveresiduals in reducing pumping work0.10.150.20.250.30.350.40.450.50 2 4 6 8 10 12 14 16SurfacetoVolumeRatioatTDC[1/mm]4-Stroke Engine Displacement [L]API OP6 2-stroke diesel4-stroke diesel30% lower
  • 12©2013Achates Power, Inc. All rights reserved.Key Questions To Be Addressed Today Who is Achates Power? Why can an opposed-piston, two-stroke diesel engine be more fuelefficient than a four-stroke diesel? Why can an opposed-piston, two-stroke diesel engine have superioremissions performance? What has been demonstrated via dynamometer testing? How are the historical challenges of opposed-piston, two-strokediesels addressed? How does this compare with four-stroke fuel efficiency and emissionimprovement actions? How should you validate a game-changing, disruptive technology?
  • 13©2013Achates Power, Inc. All rights reserved.Why Does an OP2S Diesel Have Superior Emissions?• By selecting an appropriatepower density, the OP2S dieselhas lower peak cylinderpressures and lower peaktemperatures and, therefore, canmeet more stringent NOxemissions limits withoutsignificant calibration trade-offs• In addition, our OP2S diesel hasa very high Exhaust GasRecirculation (EGR) tolerance.EGR also reduces peaktemperatures and therebyreduces NOx.4-Stroke Disp.4-StrokeBMEP05101520250 2 4 6 8BMEP(bar)Displacement (L)BMEP/Displacement Trade-OffComparison to 4-Stroke Engine at Rated Power™Source: Kaario O., Antila E. and Larmi M. Applying sootphi‐T maps for engineering CFD applications in dieselengines, SAE 2005‐01‐3856, 2005
  • 14©2013Achates Power, Inc. All rights reserved.Fuel Injection SystemPiston Bowl ShapeWhy Does an OP2S Diesel Have Superior Emissions?By selecting the appropriate injection strategy (hole size, spray pattern, fuel railpressure, start of injection and duration timing) coupled with the appropriate pistonbowl shape, the opposed injection sprays can avoid impinging upon one another andcan avoid contact with the piston crown. This results in low particulate matter.
  • 15©2013Achates Power, Inc. All rights reserved.Key Questions To Be Addressed Today Who is Achates Power? Why can an opposed-piston, two-stroke diesel engine be more fuelefficient than a four-stroke diesel? Why can an opposed-piston, two-stroke diesel engine have superioremissions performance? What has been demonstrated via dynamometer testing? How are the historical challenges of opposed-piston, two-strokediesels addressed? How does this compare with four-stroke fuel efficiency and emissionimprovement actions? How should you validate a game-changing, disruptive technology?
  • 16©2013Achates Power, Inc. All rights reserved.1.6L Single-Cylinder Measured Data00.250.50.751020406080100120140160180200220240-30 0 30 60 90nAMFB(-)AHRR(J/deg)Crank Angle (deg aMV)1.6L Single CylinderINDICATEDRESULTS SUMMARYOPERATING CONDITIONS HEAT RELEASE ANALYSISSpeed 1203 (rpm) CA10 -3.4 (deg aMV)Delivered AirFlow 141.3 (kg/hr) CA50 2.0 (deg aMV)Fuel Mass 62.7 (mg/rev) CA90 14.4 (deg aMV)SOI -6.0 (deg aMV) BurnDuration (10-90) 17.8 (deg aMV)InjectionDuration 6.7 (deg) EnergyReleased 2701.1 (J)InjectionPressure 1200 (bar)CALCULATED OUTPUTSAVERAGE GASTEMPERATURESIMEP 8.8 (bar)IntakeManifold Inlet 324.5 (K) Indicated Thermal Efficiency 53.2 (%)Intake Manifold 323.3 (K) IndicatedPower 28.9 (kW)ExhaustManifold 588.8 (K) IndicatedTorque 229.1 (N-m)ExhaustManifold Outlet 566.0 (K) PeakPressure 142.0 (bar)Loc.of Peak Pressure 5.0 (deg aMV)AVERAGE GAS PRESSURES MPRR 8.4 (bar/deg)IntakeManifold 2.10 (bar) Loc.of MPRR -1.0 (deg aMV)ExhaustManifold 2.01 (bar) ISFC 156.8 (g/ikW-hr)ISCO2 497.0 (g/ikW-hr)EMISSIONS-BASED CALCULATIONS ISCO 0.08 (g/ikW-hr)Delivered AF 28.4 (-) ISNOX 3.772 (g/ikW-hr)ISHC 0.211 (g/ikW-hr)Combustion Efficiency 99.9 (%)EGR Rate 30.4 (%) ISSoot 0.005 (g/ikW-hr)CylinderPressure(Bar)
  • 17©2013Achates Power, Inc. All rights reserved. Out of 100% fuel energy, the single-cylinder test results cover heat losses and the air flow enthalpies. Indicated thermal efficiency doesn’t take into account pumping and friction. Pumping losses for a multi-cylinder includes Supercharger, Turbocharger, Charge Air Cooler andExhaust Aftertreatment System. Brake thermal efficiency is indicated efficiency minus pumping minusfriction losses.020406080100Exhaust-IntakeEnthalpyHeatTransferIndicatedThermalEfficiencyPumpingLoss:SC, TC, CAC, EATSFrictionBrakeThermalEfficiencyPercentFuelEnergySingle-CylinderMeasurementMulti-CylinderPredictionData Generation ProcessFrom Indicated to Brake-Specific Values
  • 18©2013Achates Power, Inc. All rights reserved.Multi-Cylinder Interface Model Input Data Input data into GT-Power model are a combination of test cell data and a set of application-specificassumptions. The multi-cylinder model also considers wave dynamics and tuning effects.Geometry Data:stroke/boredisplacementnumber of cylinderscompression ratioAir ChargeSystem:scaled TC,SC maps,EGR systemEngine CoolingSystem:CAC and EGR coolerperformance,coolant temperaturesAftertreatmentSystem:backpressurerepresentative of fullaftertreatmentMulti CylinderPerformance ModelSingle CylinderTest Data:speed, fuel & airmass, pressures &temperaturesPerformance Report:Brake-specific data:BSFC, BMEP, BSNOx, BSPM, etc.Friction:Chen-Flynn modelparameterizedaccording internalcorrelated modelCombustionSystem:rate of heat release,excess air ratioEGR rateTest DataAssumptionsLegend:Data Generation ProcessScavengingCharacteristics:measured with high-speed sampling
  • 19©2013Achates Power, Inc. All rights reserved.OP Engine Performance AdvantageComparison of optimized OP2S engine vs. conventional, state-of-the-art medium-duty engine 15% “best point” advantage 22% cycle-average advantage (20.8% at equivalent engine-out NOx)Best Point48.5% BTEBest Point40.9% BTEOP2S
  • 20©2013Achates Power, Inc. All rights reserved.Engine Speed (RPM)Torque(n/m)BSFC Map HD 2016800 1000 1200 1400 1600 1800 2000 2200 24002004006008001000120014001600180020002200BSFC(g/kW-hr)160170180190200210220230240250260270280290300310320Projected Heavy-duty OP2S BSFC Map 11 Liter, 3-cylinder 2000-2500 Nm Max Torque 400-500hp Max PowerBest Point51.5% BTE
  • 21©2013Achates Power, Inc. All rights reserved.Key Questions To Be Addressed Today Who is Achates Power? Why can an opposed-piston, two-stroke diesel engine be more fuelefficient than a four-stroke diesel? Why can an opposed-piston, two-stroke diesel engine have superioremissions performance? What has been demonstrated via dynamometer testing? How are the historical challenges of opposed-piston, two-strokediesels addressed? How does this compare with four-stroke fuel efficiency and emissionimprovement actions? How should you validate a game-changing, disruptive technology?
  • 22©2013Achates Power, Inc. All rights reserved.Practical ConsiderationsPackagingWrist Pin Durability-600000-500000-400000-300000-200000-1000000100000200000-160000-140000-120000-100000-80000-60000-40000-2000002000040000600000 120 240 360 480 600 720ForceinWristpin(N)Crank Angle (deg)Wristpin loads for typical 4-Stroke vs 2-Stroke4-stroke2-stroke0CompressiveTensileOil Consumption VersusPower Cylinder DurabilityFuel specific oil consumptionPiston Thermal Mgmt.
  • 23©2013Achates Power, Inc. All rights reserved.Oil Control Design Parameters Liner temperature Bore texture, form after honing, form atoperating temperature Oil ring tension Scraper element conformability Ring end gaps, end chamfers and landchamfers Groove tilt, pinch, keystone angle, textureand flatness Ring side clearance, cross sealing andside sealing Volume behind ring, volume between rings
  • 24©2013Achates Power, Inc. All rights reserved.Da Vinci Lubricant Oil Consumption (DALOC™)Oil Measurement System Measures piston/ring/liner and turbochargerlubricant losses Measurement principle: Sulfur free fuel (< 2 ppm) Oil with known sulfur (~3500 ppm) Excite SO2 in exhaust with ultraviolet light Quantify fluorescence Technology benefits: Real-time resolution Sensitivity: <0.1 g/hr. minimum detection limit Repeatability: <2% test-to-test Accuracy: <10% from other methods Non-intrusive, non-destructive Insensitive to air, fuel or soot dilution in the lubricant oil
  • 25©2013Achates Power, Inc. All rights reserved.OP2S Oil Consumption ResultsWeighted cycle-averageAverage of three runs.Conclusion:The OP2S engine achieved weighted, cycle-average, fuel-specific oil consumption of 0.11% with allpoints in the operating map < 0.18%. This beats the best two-stroke results published in the literatureand is within the range of state-of-the-art, heavy-duty, four-stroke engines.Best two-stroke inliteratureModern heavy-dutyfour-strokeBest in class
  • 26©2013Achates Power, Inc. All rights reserved.-600000-500000-400000-300000-200000-1000000100000200000-160000-140000-120000-100000-80000-60000-40000-2000002000040000600000 120 240 360 480 600 720ForceinWristpin(N)CrankAngle (deg)Wristpin loads for typical 4-Stroke vs 2-Stroke4-stroke2-strokeWrist Pin0CompressiveTensile
  • 27©2013Achates Power, Inc. All rights reserved.Biaxial Wrist Pin BearingLadder-type bearing andcorresponding biaxial bearing
  • 28©2013Achates Power, Inc. All rights reserved.Biaxial Bearing Analysis ToolThe bearing parameters (clearance, axis spacing, etc.) are optimized to provide adequateMOFT, filling, film density and film pressure.
  • 29©2013Achates Power, Inc. All rights reserved.Piston Thermal Management Countermeasures Management of the “hot side” – that is, combustion strategy: Piston bowl geometry Injection – i.e., spray pattern, number of holes, hole size Calibration – start of injection, duration, air/fuel ratio Liner & manifold – port-to-port balance, swirl Management of the “cold side” Cooling gallery – geometry and fill ratio Oil jets – number and flow rate Oil flow through the connecting rod Material selections Crown and skirt Anti-oxidation coatings Appropriate power densities Etc.
  • 30©2013Achates Power, Inc. All rights reserved.Detailed CFD Results: Baseline vs. Best CandidateGeneticAlgorithmsBest
  • 31©2013Achates Power, Inc. All rights reserved.5Thermocouple Measurement / FEA ExtrapolationBowl<520 CPin<180 CRings<285CUndercrown<285CSurface Temperature Limits1 & 36 & 7TemplugModel includes:1. Temperature-dependent material properties2. Epoxy thermal conductivity3. Hot-side zones (flame contact)4. Cold-side zones (impingement, galleryshaking)
  • 32©2013 Achates Power, Inc. All rights reserved.Key Questions To Be Addressed Today Who is Achates Power? Why can an opposed-piston, two-stroke diesel engine be more fuelefficient than a four-stroke diesel? Why can an opposed-piston, two-stroke diesel engine have superioremissions performance? What has been demonstrated via dynamometer testing? How are the historical challenges of opposed-piston, two-strokediesels addressed? How does this compare with four-stroke fuel efficiency and emissionimprovement actions? How should you validate a game-changing, disruptive technology?
  • 33©2013Achates Power, Inc. All rights reserved.02004006008001,0001,2001,4001,6000% 1% 2% 3% 4% 5% 6% 7%Conventional Engine Efficiency Technology RoadmapWaste heat recoveryImproved fuel injection system$per%FuelConsumptionImprovementFrictionreduction -engineVariabledisplacementpumpAccessory electrificationImprovedturbochargerSources: TIAX, National Academy of Engineering, Achates Power, Inc.% Fuel Consumption ImprovementIncrease cylinder pressureFrictionreduction -accessories
  • 34©2013Achates Power, Inc. All rights reserved.Key Questions To Be Addressed Today Who is Achates Power? Why can an opposed-piston, two-stroke diesel engine be more fuelefficient than a four-stroke diesel? Why can an opposed-piston, two-stroke diesel engine have superioremissions performance? What has been demonstrated via dynamometer testing? How are the historical challenges of opposed-piston, two-strokediesels addressed? How does this compare with four-stroke fuel efficiency and emissionimprovement actions? How should you validate a game-changing, disruptive technology?
  • 35©2013Achates Power, Inc. All rights reserved.How To Validate a Game-Changing TechnologyThe opposed-piston, two-stroke engineProvides a step-function efficiency improvementMeets emissions requirementsHas fewer parts, less mass, lower costsDemonstrated, enduring advantages……a game changer.Key validation stepsSound thermodynamic and combustion basis for claimsPublished and peer-reviewed data backing up those claimsNo unsolvable implementation issues
  • 25 Companies to Watch in Energy TechFor More InformationContact:koszewnik@achatespower.com+1 858.535.9920, ext. 301Visit:www.achatespower.com