Browse Topic: Multifuel engines

Items (25)

Data-driven Modeling and Control Framework for Multi-Fuel Compression-Ignition Engines

2025-01-8349

4/1/2025

Controlling the combustion phasing of a multi-fuel compression ignition engine in varying ambient conditions, such as low temperature and pressure, is a challenging problem. Traditionally, engine control is achieved by performing experiments on the engine and building calibration maps. As the number of operating conditions increase, this becomes an arduous task, and model-based controllers have been used to overcome this challenge. While high-fidelity models accurately describe the combustion characteristics of an engine, their complexity limits their direct use for controller development. In recent years, data-driven models have gained much attention due to the available computation power and ease of model development. The accuracy of the developed models, which, in turn, dictates the controller’s performance, depends on the dataset used for building them. Several actuators are required to achieve reliable combustion across different operating conditions, and obtaining extensive experimental datasets across all these conditions can be difficult. This work proposes utilizing a dataset from a high-fidelity model such as CFD to build an approximate Gaussian Process Regression (GPR) model with the Variational free-energy (VFE) methods. The developed model is then used for guided engine testing and controller development. Simulations using experimental and CFD datasets to demonstrate combustion phasing tracking performance were performed. Using the proposed methodology, a root mean square error of less than 1 degCA was obtained across the developed maps.

Govind Raju, Sathya Aswath, Sun, Zongxuan, Kim, Kenneth, Kweon, Chol-Bum

Experimental Investigation of Plastic Pyrolysis Oil in DI Diesel Engine to Analyze Performance and Emission Characteristics

2023-28-0062

11/10/2023

Disposal of non-biodegradable plastic waste is one of the major hindrances for many countries. The research works in area of plastic waste management expands almost like every day. The conversion of waste to energy recovery is one of the promising techniques found to manage the waste plastic. Waste plastics have the dominating factor for fuel production since they have good heat of combustion and also their growing availability. The present work examines the potential of using blends of plastic oil (PO) with diesel in a direct injection diesel engine. The plastic oil is synthesized through pyrolysis process from mixed plastic waste, which has got more potential for scalable implementations. The present work includes the production of PO, characterization of the produced PO, performance and emission testing in a single cylinder four stroke VCR multi fuel engine. The engine is fueled with blends of plastic oil with diesel. Four blends of plastic oil with diesel (5% PO, 10% PO, 15% PO and 20% PO) are prepared on a volumetric basis. The test results show that brake thermal efficiency of blends is lower compared to diesel. Yet 10% PO shows similar performance to that of diesel fueled operation. The regulated emissions are reduced considerably when compared to Diesel fueling. Among all the test compositions, 10% PO shows better emission characteristics. 10% PO shows lower unburned hydrocarbon, CO, CO2 and smoke compared to other test fuels.

Sebastian, Jilse, Jose, Sachin, Vijayakumar, Anandhu

Combustion Regimes in the Chrysler Multi-Air Multi-Fuel Engine, Part 1 - Diesel Assisted Spark Ignited

2023-01-0231

4/11/2023

This paper is the first of three papers stemming from a dual fuel Chrysler prototype engine which uses both diesel and gasoline direct injection running at stoichiometric conditions, as part of a project to explore the viability of incorporating an engine platform which utilizes low temperature combustion regimes into a modern automotive application. The combustion system used high rates of EGR while maintaining combustion stability by using high charge motion intake port and a high energy ignition system. The engine ran highly dilute SI combustion at low loads, Diesel Assisted Spark Ignition at medium loads and a transition to Diesel Micro Pilot ignition at medium to high load. This paper explores diesel assisted spark ignited combustion at medium loads 6.5 bar to 12.7 bar BMEP. The second paper will explore the use of diesel micro-pilot ignition at high loads 10.6 bar to 14.5 bar BMEP and the third paper to be published in 2024 will explore fuel property effects (mainly Cetane and Octane) through the use of alternative fuels. In the diesel assisted spark ignited combustion regime combustion is initiated via a spark while using a diesel injection to provide a low octane fuel source early in combustion. Results were obtained at speed/load points ranging from 1500 to 3200 RPM and boost levels ranging from 95 to 200 kPa. Spark timing, diesel injection timing, and exhaust gas recirculation percentage were crucial variables affecting the performance of the engine. Brake thermal efficiency levels above 39% were possible at numerous operating conditions.

Church, William, McConnell, Steven

Combustion Regimes in the Chrysler Multi-Air Multi-Fuel Engine, Part 2 - Diesel Micro-Pilot Combustion

2023-01-0222

4/11/2023

This paper is the second of three papers stemming from a dual fuel Chrysler prototype engine which uses both diesel and gasoline direct injection running at near-stoichiometric conditions, as part of a project to explore the viability of incorporating an engine platform which utilizes low temperature combustion regimes into a modern automotive application. The combustion system was designed to tolerate high rates of EGR while maintaining combustion stability by using high charge motion intake port and a high energy ignition system. The engine ran on highly dilute SI combustion at low loads, Diesel Assisted Spark Ignition at medium loads and a transition to Diesel Micro Pilot ignition at medium to high load. The first paper explored the use of Diesel Assisted Spark Ignited at moderate loads 6.5 bar to 12.7 bar BMEP and the third paper to be published in 2024 will explore fuel property effects (mainly Cetane and Octane) through the use of alternative fuels. This paper explores the use of DMP at high loads 10.6 to 14.5 bar BMEP. In the Diesel Micro-Pilot mode, a small quantity diesel injection is used to initiate the combustion of a gasoline-air mixture. Testing was accomplished for engine speeds of 2000 RPM and 2400 RPM with boost levels of 180 kPa to 220 kPa. The engine was optimized to operating points using diesel injection timing and diesel percentage of total fuel mass. Results are presented for both brake thermal efficiency and emissions data. The engine produced brake thermal efficiency levels of 40%.

Church, William, McConnell, Steven

Q&A

21AUTP04_124/1/2021

Achates Power's 2-stroke, opposed-piston, compression-ignition, multi-fuel engine marches toward multiple applications - and series production in 2024. Larry Fromm explains. Global demand for cleaner, more power-dense internal combustion engines (ICE) is expected to continue into the middle of this century, for a variety of vehicle applications and markets. San Diego-based Achates Power has been developing its solution - an advanced 2-stroke, opposed-piston, multi-fuel, compression-ignition engine - since 2004, the year computer engineer Larry Fromm joined the start-up to lead business development. Automotive Engineering recently caught up with him to learn about Achates' progress in moving its innovative OP power unit toward series production in 2024. Highlights of our interview are below.

Automotive Direct-Injection Stratified-Charge Engine Development in the 1970-1980’s

2016-01-0175

4/5/2016

Spark-ignition direct-injection technology existed since about 1930 for the primary purpose to give multifuel capability over what the compression-ignited diesel engine could provide. In subsequent decades development of multifuel engines continued both as higher-compression-ratio “spark-ignited diesel” and moderate-compressionratio stratified-charge engines. Global events in the 1960-1970’s, namely the oil embargo, oil-supply crises, and the passage of the U.S. Clean Air Act intensified interest in such engines. The military and large commercial fleet operators were particularly focused on efficiency and multifuel capability over concerns for fuel supplies. Automobile manufacturers were focused on gasoline-fueled efficiency and the potential to reduce engine-out legislated NOx emissions with the stratified-charged combustion systems. In this paper the major direct-injection spark-ignited stratified-charge concepts pursued during the 1970-1980’s are reviewed at a high level, and relevant references are cited. Examination of this development history should be of interest to those working on modern gasoline direct-injected engines, as a variety of concepts were pursued, with the physics of those combustion processes being pertinent to today’s systems in production and under development. In many cases advances in fuel-injection hardware, enabled by modern manufacturing methods, and control technologies, enabled by modern computers and sensors, have allowed design objectives of the past to be implemented successfully today.

Groff, Edward G.

FUEL COMPENSATION SOLUTION FOR A MULTI-FUEL CAPABLE DIESEL ENGINE

2024-01-3534

8/4/2015

ABSTRACT This paper describes the approach used to improve the fuel flexibility of a high power density diesel engine intended for tactical combat applications. The objective of this work was to demonstrate a technically feasible solution that mitigated the negative performance impacts encountered when commercial and military-grade aviation fuels are used in diesel engines that were calibrated with standard Type 2 diesel fuel. To accomplish this objective, modifications to the engine calibration and the implementation of a fuel compensation algorithm, which used cylinder pressure feedback, resulted in successful demonstration of meeting the program requirements of maintaining acceptable combustion quality and maximum power output to within ± 2 percent of the rated power target regardless of the fuel type supplied to the engine.

Neely, Gary, Ng, Cheuk, Reinhart, Thomas, Coppersmith, Robert, Combi, Anthony

Chrysler sees the ICE future

13AEID1001_01

10/1/2013

The three-year, $30 million Multi-fuel MultiAir R&D program with the U.S. DOE is nearing completion. Here's what Chrysler Powertrain engineers have learned as they try to achieve a 25% fuel-efficiency gain. Chrysler's ambitious program to demonstrate a 25% combined city/highway FTP fuel-efficiency improvement in a production minivan has entered the final and most critical phase of development. With dyno testing of the advanced 2.4-L dual-fuel inline four successfully completed, the powertrain next must prove itself under real-world operating conditions. “So far, we're very happy with this program,” Chris Cowland, Chrysler's Director of Advanced Engineering and SRT Performance, told AEI. “But now comes the biggest challenge-making the engine fully drivable in a car, while meeting Tier 2 Bin 2 emissions levels and feeling like a normal engine to the end customer. And we have to do it by April.”

Brooke, Lindsay

A NEW TECHNIQUE TO ENABLE DIESEL ENGINES TO AUTONOMOUSLY OPERATE ON DIFFERENT MILITARY FUELS

2024-01-3416

8/20/2013

SUMMARY Autonomous operation of diesel engines using different military fuels faces many challenges. Engines should be able to use Jet Propellant-8 (JP-8) fuel, as well as alternate and renewable fuels intended to replace petroleum-derived jet or diesel fuels. These fuels can have wide ranges of physical and chemical properties. In addition, diesel engines that power military ground vehicles are originally manufactured for commercial applications which are equipped with additional after treatment devices needed to the meet emission standards. Such devices are not needed in military vehicles. However, commercial engines and after treatment devices are calibrated as one system to meet the emission targets, causing some penalty in fuel economy and peak power. These engines should be recalibrated to produce the highest power density and the best fuel economy required in military vehicles. Furthermore, commercial engines are optimized to operate on ULSD (Ultra Low Sulfur Diesel) fuel, which has narrow specifications. This is not the case in military engines which should be able to operate on JP-8 and other approved alternate fuels which have wide ranges of Cetane Numbers (CN), density, and volatility. It should be noted that all these challenges are related to the combustion process. This paper presents a new technique developed to sense and control the combustion process for different fuels. This technique is based on the ionization in hydrocarbon-air flames. The measured ion current is analyzed in detail to determine the autoignition and combustion characteristic of the fuel used in the engine. This is followed by the development of a control strategy to phase the combustion process of different fuels in order to achieve the targets of improved fuel economy, high power density and reduced soot emissions in military vehicles.

Henein, Naeim. A., Bryzik, Walter, Badawy, Tamer, Muzzell, Pat., Schihl, Pete, Sattler, Eric, Johnson, Nick

Multifuel Engine Performance, Emissions and Combustion Using Anhydrous and Hydrous Ethanol

2012-36-047510/2/2012

The increasing ethanol participation in Brazilian fuel market and its supply and price oscillations, motivate studies on multifuel engines behavior with the two specified types of ethanol in Brazil, the anhydrous and the hydrous fuels. The present work includes a comparative engine test bed performance study of a multi-fuel engine equipped with a programmable electronic central unit (ECU), fueled with anhydrous and hydrous ethanol. Fuel properties, engine performance, emissions and combustion parameters are reported using these two fuels for maximum power operating point. The programmable ECU was installed in order to make possible the setting of some parameters that are not accessible in engines operating with commercial ECU. This way, torque was optimized regarding spark timing and air fuel ratio, for all selected fuels and engine conditions tested. Test results presented the effects of anhydrous and hydrous ethanol on a multi-fuel engine performance, emissions and combustion. Additionally, some performance and emissions correlations with combustion parameters are presented.

Villela, Antonio Carlos Scardini, Machado, Guilherme Bastos

Top technology stories of 2010

10AEID1207_01

12/7/2010

The editors compiled this top 10 of the past year's most significant automotive-engineering articles based on the online activity of our readers. Managerial responsibility is key to earning a fat paycheck, according to the results of a first-of-its-kind global survey of automotive, aerospace, off-highway, commercial vehicle, and other mobility engineers. “The biggest impact on an engineer's compensation is how many people you supervise, and the differential between managing five to 10 persons or managing 10 or more engineers was as much as $20,000. That's a real eye-opener,” said Bill Cariello, Manager of Web Strategy/Operations for SAE International, during an SAE Convergence 2010 press conference on the survey Oct. 19. SAE's mobility engineering salary survey of SAE members and nonmembers was compiled from online questionnaires completed by 5288 engineers working across the globe. “There is quite a substantial pay difference between an engineer having a bachelor's degree and a master's degree. Having a master's degree can bump an engineer's annual salary by approximately 21%. But the difference between an engineer with a master's degree and an engineer with a Ph.D. is 5% or less,” Cariello said. Read full story at www.sae.org/mags/aei/9005

Individual Cylinder Fuel Control Application with a Switching Oxygen Sensor

2010-36-0028

10/6/2010

In this paper we discuss in detail an algorithm that addresses cylinder-to-cylinder imbalance issues. Maintaining even equivalence-ratio (θ) control across all the cylinders of an engine is confounded by imbalances which include fuel-injector flow variations, fresh-air intake maldistribution and uneven distribution of Exhaust Gas Recirculation (EGR). Moreover, in markets that are growing increasingly cost conscious, with ever tightening emissions regulations, correcting for such mismatches must not only be done, but done with no additional cost. To address this challenge, we developed an Individual Cylinder Fuel Control (ICFC) algorithm that estimates each cylinder's individual θ and then compensates to correct for any imbalance using only existing production hardware. In our production-bound algorithm, modeling and control of the cylinders' dynamic θ was performed using a single switching oxygen sensor. Our ICFC algorithm was developed on a 2.4-l four-cylinder DOHC engine and it is in production at 2010 Multifuel engines 1.0, 1.4 and 1.8L four-cylinders SOHC selling a volume of 90 k/year. It meets internally defined performance requirements and NLEV emissions. Other important contributions in this work include an analysis of exhaust gas transport and mixing phenomenon, and an analysis of digitally acquiring and post processing oxygen sensor data.

Krenus, Roberto G., Costa, Herbert L.

DEVELOPMENT OF A LIGHTWEIGHT, MULTI FUEL-CAPABLE, 30-kWe APU FOR NON-PRIMARY POWER

2024-01-3098

8/18/2009

ABSTRACT A methodology for rapid development of purpose-built, heavy-fueled engines is being created. The methodology leverages best-in-class computational tools, component supplier expertise, user-programmable ECUs, and rapid prototyping to quickly provide custom engines for demanding military applications. . First-tier automotive suppliers are being used extensively on non-complex standard components to reduce the development time. Our design methodology aggressively eliminates unnecessary components and incorporates various other weight-saving features to minimize system weight. The anticipated total development time to a working prototype is less than 15 months for this first iteration of the methodology, and will be further reduced for any subsequent design iterations.

Sykes, David M., Ratowski, Jeffrey

ADVANCED LIGHTWEIGHT TURBOCHARGED 2-STROKE MULTI-FUEL VARIABLE VALVE TIMING AND VARIABLE COMPRESSION RATIO MILITARY ENGINE

2024-01-3103

8/18/2009

ABSTRACT The latest advancements in common rail fuel injection system, material science, engine control strategies, and manufacturing technologies have challenged and allowed engine designers to create a high power density, fuel efficient, reliable, and environmental friendly multi-fuel engine. To increase power density a novel high-speed 2-stroke turbocharged compression ignition engine will feed the pressurized air directly into the combustion chamber without going through the crankcase. Thus, only pressurized clean air will be used for combustion and oil consumption will be dramatically reduced. To further improve volumetric efficiency and reduce emissions, a computer controlled dynamic variable valve timing system can be incorporated such that the optimum amount of pressurized air will be available for combustion at various loads and conditions. Combustion efficiency at different loads can be optimized by adjusting the compression ratio dynamically through computer control. By controlling the fuel injection strategies through advanced engine calibration one can optimize engine horsepower, fuel economy, and emissions with multiple fuels. Parasitic losses can be minimized by reducing friction and pumping losses. Lightweight metal alloys and composite materials that have been well proven in the motorsports and aerospace industries can be used to replace a variety of engine components that are currently made of steel, iron, and aluminum to reduce the weight-to-power ratio to be close to 1. The result is a versatile, lightweight, high power density, reliable, fuel efficient, and “green” multifuel engine that will enable soldiers to move faster, go farther, have maximum fuel flexibility, and be safer in the battle field and other operating conditions.

Chue, Stephen