Chrysler to Offer Alt-Fuel Version of Every Model
Ford and MIT in New Energy Research Partnership

Turbo-Charged, Direct-Injection E100 Engine Shows Potential for Aggressive Engine Downsizing

A turbo-charged, spray-guided direct-injection engine running on pure ethanol (E100) can achieve very high specific output, and shows “significant potential for aggressive engine downsizing for a dedicated or dual-fuel solution”, according to engineers at Orbital Corporation.

Orbital developed an E100-fueled, four-cylinder, turbo-charged direct injection engine using its air-assisted, low-pressure direct injection technology (earlier post) as a platform for investigating the potential for high specific output with ethanol.

The concept of enabling higher gasoline ICE operating efficiency through higher specific output and down-sizing is well reported in the literature. It is typical that turbo-charging is utilised to efficiently achieve high engine airflow across the engine speed range, and is coupled with direct injection to facilitate low end performance and increased compression ratio. Nonetheless specific output is still constrained by the combustion characteristics of gasoline, and whilst this may be partially offset by dilution strategies it remains the case that compression ratio and output are both limited.

It is anticipated that the operation of a turbo-charged DI engine at high load on pure ethanol may resolve these issues and deliver exceptional output, thereby enabling a more effective use of ethanol as a renewable fuel.

—Simon Brewster, “Initial Development of a Turbo-charged Direct Injection E100 Combustion System”

The injectors were centrally mounted in close proximity to the sparkplug.

The air-assist injector decouples the fuel metering and delivery events, thereby assisting the dynamic range of the injector and making it suited to boosted applications, particularly for ethanol which requires significantly higher fuel flow rates than gasoline. The low SMD [Sauter Mean Diameter] [in the order of 10µm and less] is understood to offer advantage in low temperature starting for low volatility fuels, and is therefore proposed to offer benefit for low temperature starting of ethanol.

Although designed for boosted operation on gasoline, the engine was not designed for unusual specific output, and was therefore load limited under certain conditions. Orbital performed comparative testing of ethanol and gasoline fuels in the engine at a compression ratio of 10.4:1, and under three operating scenarios:

  • Under high load at output typical of a boosted gasoline engine;

  • At extended output levels at lower and higher engine speeds; and

  • For start and light-off performance at a temperature of 25°C.

Among the key findings of the study were:

  1. At the same ignition timing and intake manifold pressure, ethanol demonstrated higher output which is attributed to higher airflow, more advantageous combustion phasing and lower heat loss.

  2. At the same ignition timing and output, ethanol required lower airflow and boost pressure, and delivered lower exhaust temperature, higher brake efficiency and lower emissions of CO2.

  3. At all speeds and loads tested, ethanol exhibited no tendency to knock and could be operated with MBT (Minimum advance for Best Torque) ignition timing (unless constrained by cylinder peak pressure).

  4. At target torque levels representative of a boosted gasoline engine, ethanol operated with lower boost pressure and MBT ignition timing, with lower exhaust temperature, higher efficiency, and lower emissions of CO2. Also resulting were an increase in cylinder peak pressure and rate of pressure rise.

  5. Engine output at speeds below 2000 rpm was significantly improved through optimization of inlet and exhaust valve timing.

  6. At speeds of 1250 and 1500 rpm, ethanol exhibited output 300 kPa BMEP higher than that of gasoline.

  7. For higher engine speeds typified at 4000 rpm, ethanol may operate at increasing load with minimal requirement for fuelling enrichment, and with ignition timing only constrained by cylinder peak pressure. On the other hand, gasoline operates at a high level of retard and requires significant enrichment to limit exhaust gas temperature, causing a significant loss of efficiency and constraining output.

  8. At a start temperature of 25°C, ethanol and gasoline show no appreciable difference in starting or light-off performance as indicated by exhaust gas temperature.

  9. The design and development of an engine intended for high output operation with ethanol should address requirements for higher compression ratio, higher peak cylinder pressure, faster rate of pressure rise, reduced incidence of pre-ignition and an injection system capable of high fuel flow rate.

Orbital is continuing its work in this area, with plans evaluate the effect of ethanol water content on high load performance; develop low temperature starting capability; and develop a turbo-charger application for transient performance and high specific output.

Resources:

Comments

Rafael Seidl

E100 has a very high octane rating (RON ~115) so it's hardly surprising that you can use the extra knock resistance to get away with higher turbo boost (laggy single or non-laggy dual stage) and a regular intercooler. Sequential turbos are not recommended for four-bangers unless HCCI is also applied in part load; otherwise, stick with banks of three to avoid exhaust manifold crosstalk due to the very small diameter, single-scroll high pressure turbo. Using some variation of DI to support better scavenging at low RPM is also not new for boosted engines.

The hard part with Orbital's concept is getting enough E100 produced and distributed.

Henrik

They could use it as a range extender in a plug-in series hybrid. The high specific power would mean longer all electric driving range since the weight of the range extender is low and cooling waste heat from the battery can be used to heat the range extender so that it will run optimally when it needs to kick in some extra power.

realarms

E100 is quite expensive to produce; typically, bio-generated ethanol is ultimately extracted as 96,4% azeotrope - meaning it can not be refined any further from a watery solution by destillation alone; however, when mixed with hydrocarbons (gasoline, diesel), the water seperates from the mixture and can be removed more easily (molecular filer, or by centrifuging the water droplets out). E100 is also quite hydrophilic, ie. it will draw water from humid air to reach the 96,4% equilibrium again.

Anyway, all the fuel parts of that engine need to be rust-resistant at least, to stand the attack by water for prolonged periods....

HealthyBreeze

Orbital? Aren't they the two-stroke guys? Did they ever find a way to meet emission requirements?

louneson

Intesting a motor that is accually optimized to run on ethanol. I would really like to see a effecientcy comparison of gas vs e100 on a hp vs hp basis. Gas has more btus but e100 is able burn more efficently.

Lad

So, if I read all these posts correctly, it take more processing, money, to produce E100; it doesn't work well as a turbo four, the company may have trouble meeting emissions requirements, you can't find it because there is a distribution problem and if we go with BEVs it might have some use as a genset Interesting! Based on these posting, I would say we have another interesting ICE experiment here with little practical use. But, then again this may be a snap decision on my part.

Roger Pham

I think that Orbital also intends for this to be used in dual fuel situation, in which the E-100 is only intended for hard acceleration, while the gasoline is used for most of the driving. Also, Orbital is working on the effect of water content in the ethanol on engine performance. The engine, of course, would have higher compression ratio than normal for increase in efficiency on par with Diesel, and to prevent engine knock, delay intake valve closure at medium engine power to simulate Atkinson cycle or using cooled EGR, and at high power, use ethanol with varying degrees of boost instead. The engine will not be boosted while on gasoline alone.

I believe that as long as the E-100 is separted from the gasoline, water mixed with the E-100 to bring down the ethanol content to 96% would be okay for engine operation. Just besure that the engine injector and the fuel line will be refilled with gasoline before shutting off the engine to prevent rust formation.

The use of Orbital injectors and dual fuel with E-100 and lower-cost turbocharger due to lower exhaust temperature will mean lower cost premium than with the MIT's approach of using conventional GDI injectors with much higher pressures, for dramatic engine down-sizing.

Of course, if the EPA will make a rule to restrict cars' and trucks' maximum acceleration 0-60mph to slower than 12-14 seconds, we won't need any of this fancy technology. For example, a 1978 Chevy Caprice at 5000 lbs can accelerate from 0-60mph in ~12 seconds using a 5.7 liter V-8 engine with 170-hp output to a 3-speed hydramatic transmission. Now, a mediocre 2-liter I-4 normally-aspirated engine having ~150 hp can do the same job to a 5000-lb car using a 4-5 speed transmission.
For a 3000-lb car, we will need but a mediocre low-tech 1.3-liter engine to do the same job (0-60mph in 12.5 seconds). How many 3000-lb car do we see today with 1.3 liter engine?

The 2888-lb Honda Civic Hybrid almost qualifies, having a 1.3 liter 93-hp engine, giving it a hwy 50-mpg rating. Now, this, with a micro-hybrid system having a puny motor and 0.3 kwh battery for a low purchasing cost, will bring its overall mpg to ~48 or so...a far cry from the typical 27 mpg overall rating that cars of this size will get. Who, then, can say that fuel efficiency has got to be expensive?

rob

If you're not mixing it with petroleum, a "watery" mix of ethanol in your engine isn't a bad thing. The water increases resistance to detonation and provides additional charge cooling.

No need for it to be anhydrous, which cuts the price a lot.

ralph

Surprised to see the E100 piece floating around,it wasn't a press release,it was from a paper presented a month or so ago.
The entire paper is available on Orbitals website if anyone desires.

There will be an interesting follow up paper at the SAE Brazil meeting in NOV.,the abstract is below.

The Effect of E100 Water Content on High Load Performance of a Spray Guide Direct Injection Boosted Engine
Co Autor

Segmento / Segment
Veículos de Passeio
Resumo / Abstract
Gasoline and diesel fuels present issues for security of supply, renewability and environmental impact in respect of greenhouse gas emissions. There is significant need to reduce dependence on liquid fossil fuels by both optimising engine efficiency and identifying suitable alternatives.

A renewable fuel of particular interest is ethanol, established in Brasil as a gasoline diluent and in pure azeotropic form. Operating a vehicle on pure ethanol is attractive due to reduced dependence on fossil fuel and also the enabling of an aggressive engine down-sizing strategy, which will significantly enhance engine operating efficiency.

Whilst anhydrous E100 yields high specific output the addition of water presents challenges and opportunities. On one hand the required mass delivery increases to achieve the same energy input, and the challenge for fuel preparation is greater. On the other hand the charge cooling effect will be higher and charge dilution will be increased.

The current study investigates the effects of water content on high load performance of a spray guided DI turbocharged multicylinder engine. Pure ethanol with varying water content is used to fuel the engine under heavily boosted operation, and results are presented of combustion characteristics, specific output and emissions. The data is explained in terms of the fundamental effects of water content, and conclusions are drawn regarding the potential for high output engines operating on real world E100 fuel

ralph

the list below is for some naysayers when it come to anything or anyone they disagree with or just don't like.
Orbital is a company that has done more for the enviroment(for their own gain)than many others
The papers below have been presented sine the early eighties and they do have numerous products on the market and a licencee list that includes GM on down.
You can also find close to 15(recent) patents generated by Honda protecting their recent work on engines with Orbitals DI.
Not spam,not lies,just facts

or to print copies, where available, at no cost within the constraints shown on the individual papers or the footnotes following the table below.

Year Title Author Company Conference Paper # Paper Pres
2007 Initial Development of a Turbo-charged Direct
Injection E100 Combustion System* S Brewster Orbital 14th Asia Pacific Automotive
Engineering Conference, Hollywood, California 2007-01-3625 PDF
2007 Experimental and Theoretical Study of an Air-Assisted Fuel Injector for a D.I.S.I. Engine* H Carlisle, A Boretti, S Jin, G Zakis, M Brear, W Attard, H Watson, W Bryce Orbital, University of Melbourne, Holden Australia SAE World Congress & Exhibition, Detroit 2007-01-1415 PDF
2006 A Study of Efficiency and Emissions for a 4-Stroke SI and a CAI Engine with EGR and Light Boost* G Cathcart, J Gaynor, R Fleck, R Kee, R Kenny Orbital, Queens University of Belfast SETC, San Antonio 2006-32-0042 PDF
2006 Development of a Natural Gas Spark Ignited Direct Injection Combustion System G Cathcart, D Caley Orbital NGV2006, Cairo
2006 Development of Lightweight 2-Stroke & 4-Stroke Heavy Fuel UAV Engines G Cathcart, J Tubb, G Dickson, B Schmidt Orbital AUVSI, Orlando
2005 The Application of Air-Assist Direct Injection for Spark-ignited Heavy Fuel 2-Stroke and 4-Stroke Engines* G Cathcart, G Dickson, S Ahern Orbital SETC, Bangkok 2005-32-0065 PDF
2005 High Specific Power Output Direct Injection 2-Stroke Engine Applications* R Houston, G Bell, S Ahern Orbital SETC, Bangkok 2005-32-0066 PDF
2004 125cc Small Engine Fuel Injection System with Low Emissions Solutions* D Worth, K Yang, K Hayakawa, S Yamazaki, S Takenaka, H Oshiba Orbital, Mikuni SETC, Graz 2004-32-0094 PDF
2004 The Potential of Gasoline Direct Injection for Small Displacement 4-Stroke Motorcycle Applications G Cathcart, R Houston, S Ahern Orbital SETC, Graz 2004-32-0098 PDF
2003 Fuel Economy Advantages on Indian 2-stroke and 4-stroke Motorcycles fitted with Direct Fuel Injection S Leighton, S Ahern Orbital SIAT, Pune 2003-26-0019 PDF
2002 Air Assisted Direct Injection - Fuel Economy with Global Emissions solutions G Cathcart, K Yang Orbital JSAE, Yokohama 20025359 PDF PDF
2002 Application of Air Assisted Direct Fuel Injection to Pressure Charged Gasoline Engines G Cathcart, J Tubb Orbital SAE International Congress, Detroit 2002-01-0705 PDF PDF
2001 Advanced Electronic Fuel Injection Systems – An Emissions Solution for both 2- and 4-stroke Small Vehicle Engines G Bell, M Archer Synerject SIAT, Pune 2001-01-0010 PDF PDF
2001 Central Injection - The Heart of the Next Generation DI_Gasoline Engine? JG Smyth, DP Sczomak, F Indra General Motors Aachener Kolloquium, Aachen PDF
2001 The Effect of Fuel Composition and Additive Content of Injector Deposits and Performance of an Air Assisted Direct Injection Spark Ignition (DISI) Research Engine H Carlisle, R Frew, J Mills, A Aradi, N Avery Orbital, Synerject, Ethyl Corp, ExxonMobil SAE Spring Fuel and Lubricants Meeting 2001-01-2030 PDF PDF
2001 Improving Robustness of Spray Guided DI Combustion Systems: The Air Assisted Approach G Cathcart, D Railton Orbital JSAE, Yokohama 20015360 PDF PDF
2000 Modeling of Two-Phase Direct Cylinder Injection P De Vos Orbital SAE International Congress, Detroit 2000-01-1393
2000 Fundamental Characteristics of an Air Assisted Direct Injection Combustion System as Applied to Four Stroke Automotive Gasoline Engines G Cathcart, C Zavier Orbital SAE International Congress, Detroit 2000-01-0256 PDF PDF
2000 A New Approach to Meeting Future European Emissions Standards with the Orbital Direct Injection Gasoline Engine D Worth, K Yang, M Brogan, D Swallow, R Brisely Orbital, Johnson Matthey 2000-01-2913 PDF PDF
2000 NVH Charactersitcs of an Air Assisted Direct Injection (DI) Spark Ignition Four Stroke Engine D Bowden, S Derry, J Dixon Orbital, University of Southampton Inst. Of Mech Engineers, European Conference on Cehcile Noise and Vibration, London Vehicle Noise and Vibration pp 65-79 PDF PDF
2000 A Five Million Kilometre, 100 Vehicle Fleet Trial, of an Air Assist Direct Fuel Injection, Automotive Two-stroke Engine D Arnall, C Pumphery, D Shawcross Orbital SAE International Congress, Detroit 2000-01-0898 PDF PDF
1999 Simplification of Air Assisted Direct Injection via Performance Benchmarking N Coplin Orbital SETC, Madison 1999-01-3310 PDF PDF
1999 Specific Engine Control Functions for an Air Assisted Gasoline DI System R Houston, D Worth Orbital Vienna Motorsymposium, Vienna
1999 An OCP Four Stroke Vehicle Application - A Practical Study of the Strategies for Future Fuel Consumption and Emissions Solutions G Cathcart, D Worth, K Yang, L Andersen Orbital Global Powertrain Congress, Stuttgart PDF PDF
1998 Air Assisted Gasoline Direct Injection R Houston, H Stocker Orbital, Siemens Automobile and Engine Technology Conference, Aachen PDF

PDF

1998 Combustion and Emission Characteristics of Orbital's Combustion Process Appied to Multi-Cylinder Automotive Direct Injected 4S Engines R Houston, G Cathcart Orbital SAE International Congress, Detroit 980153 PDF
1997 Design Considerations for the Application of Air Assisted Direct In-Cylinder Injection Systems M Stannard, M McNiff, N Coplin, D Worth Orbital SETC, Yokohama 972074
1997 Direct Injection 4-Stroke Gasoline Engines, the Orbital Combustion Process Solution R Houston, R Newmann Orbital IMechE Euro IV Challenge Future Technologies and Systems Conference, London Future Engine and System Technologies 1998-5 pp157-172
1997 Exhaust System Sensitivities with Direct Injection on a 50 cc Scooter G Bell, C Finucci Orbital SAE International Congress, Detroit 970365
1997 Application of Orbital's Low Pressure, Air Assisted fuel System to Automotive Direct Injection 4-Stroke Engines R Houston, R Newmann Orbital Engineering Foundation Conference - Engines for Automobiles, San Diego
1996 Application of Air Assisted Direct Injection to High Performance Sports Motorcycles N Coplin Orbital Petroleum Authority of Thailand, Bangkok
1996 Development of a Durable Emissions Control System for an Automotive Two-Stroke Engine R Houston, M Archer, M Mckay, R Newmann Orbital SAE International Congress, Detroit 960361 PDF
1995 Durability Development of an Automotive Two Stroke Engine K Eisenhaurer Orbital ATA, Milan 95A6006 PDF
1994 The Low Emission Orbital Combustion Process (OCP) Two Stroke Engines D Smith, S Ahern Orbital ATA, Firenze
1994 The OCP Small Engine Fuel Injection System for Future Two-Stroke Marine Engines M Cebis, M Southern, S Leighton, S Ahern, L Horner Orbital SAE: International Off-Hwy, Milwaukee 941687
1993 The Orbital Combustion Process for Future Small Two-Stroke Engines S Leighton, S Ahern, M Southern, M Cebis Orbital Institut Francais du Petrole International Seminar, Rueil Malmaison
1993 The Orbital Small Engine Fuel Injection System (SEFIS) for Direct Injected Two Stoke Cycle Engines S Ahern, S Leighton Orbital 5th Graz Two-Wheeler Symposium, Graz
1992 An Advanced Control for Orbital Direct Injected Two-Cycle Engines P Simons, M Southern, B Deutsch Orbital SAE International Congress on Transportation Electroincs, Dearborn
1991 Fuel Consumption and Emissions reduction in small disp. Two-stroke engines K Schlunke, S Ahern, S Leighton, M Kitson Orbital 4th Graz Two-Wheeler Symposium, Graz
1989 The Orbital Combustion Process Engine K Schlunke Orbital 10th International Wiener Motosymposium, Vienna
1987 Demonstration of a Flexible-Fuel Car M Southern, P Bando-padhayay, R Johnston, R Mendelsohn Orbital, CSIRO, Victorian Solar Energy Council 871164
1982 The Orbital Engine P Ewing Orbital SAE International Congress, Detroit 820348
1982 Orbital Fuel Injection System M McKay Orbital SAE International Congress, Detroit

Year Title Author Company Conference Paper # Paper Pres
2007 Initial Development of a Turbo-charged Direct
Injection E100 Combustion System* S Brewster Orbital 14th Asia Pacific Automotive
Engineering Conference, Hollywood, California 2007-01-3625 PDF
2007 Experimental and Theoretical Study of an Air-Assisted Fuel Injector for a D.I.S.I. Engine* H Carlisle, A Boretti, S Jin, G Zakis, M Brear, W Attard, H Watson, W Bryce Orbital, University of Melbourne, Holden Australia SAE World Congress & Exhibition, Detroit 2007-01-1415 PDF
2006 A Study of Efficiency and Emissions for a 4-Stroke SI and a CAI Engine with EGR and Light Boost* G Cathcart, J Gaynor, R Fleck, R Kee, R Kenny Orbital, Queens University of Belfast SETC, San Antonio 2006-32-0042 PDF
2006 Development of a Natural Gas Spark Ignited Direct Injection Combustion System G Cathcart, D Caley Orbital NGV2006, Cairo
2006 Development of Lightweight 2-Stroke & 4-Stroke Heavy Fuel UAV Engines G Cathcart, J Tubb, G Dickson, B Schmidt Orbital AUVSI, Orlando
2005 The Application of Air-Assist Direct Injection for Spark-ignited Heavy Fuel 2-Stroke and 4-Stroke Engines* G Cathcart, G Dickson, S Ahern Orbital SETC, Bangkok 2005-32-0065 PDF
2005 High Specific Power Output Direct Injection 2-Stroke Engine Applications* R Houston, G Bell, S Ahern Orbital SETC, Bangkok 2005-32-0066 PDF
2004 125cc Small Engine Fuel Injection System with Low Emissions Solutions* D Worth, K Yang, K Hayakawa, S Yamazaki, S Takenaka, H Oshiba Orbital, Mikuni SETC, Graz 2004-32-0094 PDF
2004 The Potential of Gasoline Direct Injection for Small Displacement 4-Stroke Motorcycle Applications G Cathcart, R Houston, S Ahern Orbital SETC, Graz 2004-32-0098 PDF
2003 Fuel Economy Advantages on Indian 2-stroke and 4-stroke Motorcycles fitted with Direct Fuel Injection S Leighton, S Ahern Orbital SIAT, Pune 2003-26-0019 PDF
2002 Air Assisted Direct Injection - Fuel Economy with Global Emissions solutions G Cathcart, K Yang Orbital JSAE, Yokohama 20025359 PDF PDF
2002 Application of Air Assisted Direct Fuel Injection to Pressure Charged Gasoline Engines G Cathcart, J Tubb Orbital SAE International Congress, Detroit 2002-01-0705 PDF PDF
2001 Advanced Electronic Fuel Injection Systems – An Emissions Solution for both 2- and 4-stroke Small Vehicle Engines G Bell, M Archer Synerject SIAT, Pune 2001-01-0010 PDF PDF
2001 Central Injection - The Heart of the Next Generation DI_Gasoline Engine? JG Smyth, DP Sczomak, F Indra General Motors Aachener Kolloquium, Aachen PDF
2001 The Effect of Fuel Composition and Additive Content of Injector Deposits and Performance of an Air Assisted Direct Injection Spark Ignition (DISI) Research Engine H Carlisle, R Frew, J Mills, A Aradi, N Avery Orbital, Synerject, Ethyl Corp, ExxonMobil SAE Spring Fuel and Lubricants Meeting 2001-01-2030 PDF PDF
2001 Improving Robustness of Spray Guided DI Combustion Systems: The Air Assisted Approach G Cathcart, D Railton Orbital JSAE, Yokohama 20015360 PDF PDF
2000 Modeling of Two-Phase Direct Cylinder Injection P De Vos Orbital SAE International Congress, Detroit 2000-01-1393
2000 Fundamental Characteristics of an Air Assisted Direct Injection Combustion System as Applied to Four Stroke Automotive Gasoline Engines G Cathcart, C Zavier Orbital SAE International Congress, Detroit 2000-01-0256 PDF PDF
2000 A New Approach to Meeting Future European Emissions Standards with the Orbital Direct Injection Gasoline Engine D Worth, K Yang, M Brogan, D Swallow, R Brisely Orbital, Johnson Matthey 2000-01-2913 PDF PDF
2000 NVH Charactersitcs of an Air Assisted Direct Injection (DI) Spark Ignition Four Stroke Engine D Bowden, S Derry, J Dixon Orbital, University of Southampton Inst. Of Mech Engineers, European Conference on Cehcile Noise and Vibration, London Vehicle Noise and Vibration pp 65-79 PDF PDF
2000 A Five Million Kilometre, 100 Vehicle Fleet Trial, of an Air Assist Direct Fuel Injection, Automotive Two-stroke Engine D Arnall, C Pumphery, D Shawcross Orbital SAE International Congress, Detroit 2000-01-0898 PDF PDF
1999 Simplification of Air Assisted Direct Injection via Performance Benchmarking N Coplin Orbital SETC, Madison 1999-01-3310 PDF PDF
1999 Specific Engine Control Functions for an Air Assisted Gasoline DI System R Houston, D Worth Orbital Vienna Motorsymposium, Vienna
1999 An OCP Four Stroke Vehicle Application - A Practical Study of the Strategies for Future Fuel Consumption and Emissions Solutions G Cathcart, D Worth, K Yang, L Andersen Orbital Global Powertrain Congress, Stuttgart PDF PDF
1998 Air Assisted Gasoline Direct Injection R Houston, H Stocker Orbital, Siemens Automobile and Engine Technology Conference, Aachen PDF

PDF

1998 Combustion and Emission Characteristics of Orbital's Combustion Process Appied to Multi-Cylinder Automotive Direct Injected 4S Engines R Houston, G Cathcart Orbital SAE International Congress, Detroit 980153 PDF
1997 Design Considerations for the Application of Air Assisted Direct In-Cylinder Injection Systems M Stannard, M McNiff, N Coplin, D Worth Orbital SETC, Yokohama 972074
1997 Direct Injection 4-Stroke Gasoline Engines, the Orbital Combustion Process Solution R Houston, R Newmann Orbital IMechE Euro IV Challenge Future Technologies and Systems Conference, London Future Engine and System Technologies 1998-5 pp157-172
1997 Exhaust System Sensitivities with Direct Injection on a 50 cc Scooter G Bell, C Finucci Orbital SAE International Congress, Detroit 970365
1997 Application of Orbital's Low Pressure, Air Assisted fuel System to Automotive Direct Injection 4-Stroke Engines R Houston, R Newmann Orbital Engineering Foundation Conference - Engines for Automobiles, San Diego
1996 Application of Air Assisted Direct Injection to High Performance Sports Motorcycles N Coplin Orbital Petroleum Authority of Thailand, Bangkok
1996 Development of a Durable Emissions Control System for an Automotive Two-Stroke Engine R Houston, M Archer, M Mckay, R Newmann Orbital SAE International Congress, Detroit 960361 PDF
1995 Durability Development of an Automotive Two Stroke Engine K Eisenhaurer Orbital ATA, Milan 95A6006 PDF
1994 The Low Emission Orbital Combustion Process (OCP) Two Stroke Engines D Smith, S Ahern Orbital ATA, Firenze
1994 The OCP Small Engine Fuel Injection System for Future Two-Stroke Marine Engines M Cebis, M Southern, S Leighton, S Ahern, L Horner Orbital SAE: International Off-Hwy, Milwaukee 941687
1993 The Orbital Combustion Process for Future Small Two-Stroke Engines S Leighton, S Ahern, M Southern, M Cebis Orbital Institut Francais du Petrole International Seminar, Rueil Malmaison
1993 The Orbital Small Engine Fuel Injection System (SEFIS) for Direct Injected Two Stoke Cycle Engines S Ahern, S Leighton Orbital 5th Graz Two-Wheeler Symposium, Graz
1992 An Advanced Control for Orbital Direct Injected Two-Cycle Engines P Simons, M Southern, B Deutsch Orbital SAE International Congress on Transportation Electroincs, Dearborn
1991 Fuel Consumption and Emissions reduction in small disp. Two-stroke engines K Schlunke, S Ahern, S Leighton, M Kitson Orbital 4th Graz Two-Wheeler Symposium, Graz
1989 The Orbital Combustion Process Engine K Schlunke Orbital 10th International Wiener Motosymposium, Vienna
1987 Demonstration of a Flexible-Fuel Car M Southern, P Bando-padhayay, R Johnston, R Mendelsohn Orbital, CSIRO, Victorian Solar Energy Council 871164
1982 The Orbital Engine P Ewing Orbital SAE International Congress, Detroit 820348
1982 Orbital Fuel Injection System M McKay Orbital SAE International Congress, Detroit

J

"The hard part with Orbital's concept is getting enough E100 produced and distributed."

The U.S. currently has ~440 million acres of cropland. If 100 million were planted into the sorghum(two posts back) of Ceres/Texas A&M. It would produce ~120 billion gallons of ethanol, figuring only 1200(possible +2000) gallons per acre.

http://www.greencarcongress.com/2007/10/ceres-and-texas.html#comments

Look at the emissions of BTL. Ethanol hybrid?

http://www.greencarcongress.com/2007/09/house-hearing-e.html#more

http://www.e3biofuels.com/

Ethanol is the answer.

Lad


@J:
"Ethanol as the answer"

There are some who are concerned that burning ethanol only produces smog of a different nature and I think that is under study. I hope you are right because it would certainly help us toward our goal of not having to import foreign oil.

On the subject of using gasoline and water saturated ethanol in the same engine; I'm not an engine ME but an EE by training; but, seems to me that the characteristic differences between the two fuels would lead one to believe that you would need to design and build for one or the other in order to optimize efficiency. For example: you should be able to run a higher compression ratio with ethanol because of its cooling effect, etc.

Roger Pham

J,
Ethanol is the answer for Brazil, with sugarcane aplenty, but Ethanol is NOT the answer for the USA, with energy-intensive corn crop conversion to ethanol. Cellulosic ethanol currently is still expensive (non-competitive) and still in experimental stages. However, occasional use of Ethanol stored in a separate container for use during engine turbocharge boost phase would be okay for the occasional impromptu traffic-light drag races to satisfy the testosterone surge. No ethanol, no engine boost!

Lad,
With current engine technology, there is no need for a separate engine design for optimization of both gasoline and E-100 in the same engine, as long as you don't try to produce too much power when running in gasoline powered mode. This will give you the highest efficiency in the gasoline mode, and the highest power in the alcohol E-100 mode.

fred schumacher

The key to reducing automotive fuel use, from an overall systems approach, is vehicle size and weight reduction. The essential problem is morphology. We use, on average, 4,000 pounds of vehicle to move a 200 pound payload. The advantage of internal combustion engines over batteries is their high power density. Orbital's research is very promising, especially in engine size reduction potential and cold-start operation with ethanol.
Corn ethanol is a transient phenomenon. When viable cellulosic fuel production is combined with a quadrupling of vehicle fuel efficiency (possible with today's technology if vehicle mass is reduced and aerodynamics improved) sustainability is achievable. The alternative is the burning of a lot of coal to power heavy plug-in hybrids.

Rafael Seidl

@ Fred Schumacher -

quadrupling vehicle fuel efficiency might prove a tad difficult if you keep vehicle size and functionality the same. There is still massive room for improvement, e.g. reduced weight, better aerodynamics and higher well-to-wheels efficiency of the propulsion system - but not a factor of 4.

Additional gains beyond this core engineering should be possible with better driver training and/or ergonomic features that promote the efficient operation of the vehicle.

Example: currently, if you have a manual transmission (standard in Europe) and shift up to a high gear (e.g. 5th) at moderate vehicle speed (e.g. 30mph), you need to depress the pedal severely. High torque at low RPM is good for fuel economy, but your calf will soon tire from having to produce significant force against the pedal at an uncomfortable angle. So, you shift to a lower gear, wasting fuel for the sake of comfort.

If the ECU were to interpret the accelerator position as demand for power, rather than torque, the picture would change. It could determine the most efficient way to deliver the required power, taking into account the need for reserve torque for safety and, hysteresis rules to avoid overly frequent gear changes. The driver, meanwhile, could focus on traffic rather than on operating the vehicle efficiently and suffering because of it.

You would, however, need a transmission that can select the required gear automatically, i.e. a manumatic, DCT, conventional AT or some type of CVT or EVT. In the US and Japan, that's a non-issue because virtually no-one there drives a manual. In Europe, the additional fuel savings might provide enough of an incentive to shell out for a DCT.

Wes

I wonder why they didn't move toward a higher static compression ratio if the engine was designed to run on such a high octane fuel?

Patrick

Are people really so weak that they have trouble depressing the throttle pedal? I could see having to operate the clutch often (especially with higher pressure springs in performance clutches) as tiring someone out.

My car, on anything other than a flat road or decline will not hold 30mph in 5th gear regardless of the throttle until you get into the closed loop operation at which point the ECU makes the air/fuel mixture overly rich. [This is a 2200lb vehicle that runs the 1/4 mile in ~15.0 seconds when I can get a decent 60ft time]

Roger Pham

Rafael,
You're right, quadrupling the fuel efficiency of existing vehicle fleet would be impossilbe.

However, if you would manage to reduce the weight and size from 4500 lbs to 3000 lbs, or from 3000lbs to 2000 lbs, and reduce aerodynamic drag by similar factor, you will have reduce fuel consumption by 1.5 fold.

Now, if you would reduce the engine size, either by accepting a slower acceleration, or by turboboosting while running on ethanol as featured in this article, so that you would boost the engine thermal efficiency from 20% to 35%, with perhaps micro-hybridization also, then you will have increase efficiency by 1.75 fold.
The two combined, and you can achieve 2.62 folds increase in fuel efficiency. This is not too far away from a 4-fold increase in fuel efficiency.

By going the low-tech car size reduction and low-tech engine size reduction by accepting slower acceleration, the car mfg's will have no excuse for not being able to reduce fuel consumption much much more. Up to now, car owners compete with each other by having a faster car than their peer. If the EPA will make all cars having similar acceleration fromm 0-60 in the 12-14 second range, then the speed-and-power arm race will no longer be. Car owners will then have to brag about who will have the most fuel-efficient car instead. This is good for the planet and for the future of humanity.

Wes,
The Prius has a 13:1 compression ratio while running on 87-octane fuel.

donee

Hi Roger,

The Prius has a 13:1 expansion ratio. The effective compression ratio is much less.

The Prius is faster than that 12-14 second 0-60 acceleration too. Its closer to 10.5 seconds.

So, maybe that acceleration limit should apply to cars that get less than 45 mpg EPA?

There are some Volvo guys in Europe who are using E85, converting their older turbo 2.3 liter engines. They just run higher boost to gain better efficiency, and end up with 20 % worse volume mileage (30 % would be indicated by ethanol energy per volume), which is actually a better miles/kroner result there in Sweden.

The ethanol there in Sweden comes from Brazil, I believe, so its a good thing all around. Why can't we grow sugar cane in the US ? Seems like Florida and the Gulf Coast could do it? Oakie Fanokee plantation?

Ethanol in the US is really not a fuel, but an energy transport medium, that is a way to use natural gas and coal to power cars. Hopefully that will be corrected as quickly as possible. Its very dangerous what they are doing. Burning that much coal near crop lands. It could poison the crop lands with Mercury.

Why not just make Fisher Tropf diesel and gas from coal? Probably very little difference between the two. And the coal would be mercury cleansed in the process.


Roger Pham

Hi donee,
Excellent points you've made.

The Prius and the likes have "earned" their faster acceleration priviledge by their higher level of efficiency, so 45 mpg would be a good cutoff point indeed :)

Personally, I found myself accelerating at around 3mph/second, so 0-60 mph would take around 20 seconds, and still keep up okay with traffics. 12 seconds from 0-60 would be fast. Most new cars these days are obscenely overpowered just to be competitive with the rest, and the EPA must step in to stop the arm race at some point.

Indeed, F-T from coal gasification is far cleaner and more efficient than ethanol by fermention.

Engineer-Poet

Quoth J:

The U.S. currently has ~440 million acres of cropland. If 100 million were planted into the sorghum(two posts back) of Ceres/Texas A&M....
The US does not have 100 million acres of cropland to spare.  The record corn crop of 2004 was taken from only ~78 million acres, and today's rush to plant corn for ethanol has already had serious negative effects on the production of soybeans and sunflowers.

Diverting 100 million acres of cropland means NO corn for animal feed (no beef, pork, chicken, eggs or milk) and a serious hit to other crops as well.  If ethanol is the answer, what was the question?

Quoth Fred Schumacher:

The advantage of internal combustion engines over batteries is their high power density.
No, batteries have quite adequate power density; what they have historically lacked is energy (not power) density and lifespan.  Both of these have been radically improved in just the last few years, and we're on track to replace liquid motor fuels for short distances very soon and almost all driving in the next couple of decades.

Electric motors have far higher power density than engines; the motor in the Tesla Roadster gets 250 HP out of just 70 pounds, or 3.5 HP/lb.  A typical piston aircraft engine achieves a mere 0.45-0.50 HP/lb.

Matt

I agree that the E100 (96.4%) is the way to go, but we should not use a typical gasoline I.C.E. for the testing. I've thought long and hard about this, take the typical turbo diesel engine, then tap two injectors per cylinder, one for ethonal, one for water vapor.

To start the engine would require the use of a glow plug (funny most diesels come with them now), then the vaporized water vapor would retard the ignition, allowing the high compression of the diesel engine to get the best bang from the fuel. Top this off with a turbo (typ. diesels can idle at 100 parts air to 1 part fuel with a turbo) and you can see the advantages. In stead of the typical 14:1 ratio of fuel to air in a gasoline design, the possiblity of the 100:1 can really save fuel costs. Top it off with a solar panel to charge the battery (since you don't need it except for the glow plug) and you are set.

Just a thought. Please let me know your thoughts.

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