Browse Topic: External combustion engines

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The impacts of Diesel cycle engines on the operating costs of the Cessna 172 Skyhawk and JT-A aircraft.2019-36-03211/13/2020
Diesel engines have been used on the aeronautical market for a long time. Despite this fact, there are few studies showing the potential cost savings of using this type of technology. In this way, the goal of this paper is to find out whether or not it is advantageous to use an Otto or Diesel cycle engine on general aviation light aircraft. It is well known that both of them have pros and cons, however, the possibility of using Jet A-1 (kerosene) as fuel gives the Diesel engine a clear advantage in a market like Brazil, where the price of the regular piston fuel (AvGas) keeps rising to astonishing values. Throughout this paper, a detailed study of the fixed and variable costs of two similar aircraft, both Cessnas 172 equipped with Otto and Diesel cycle engines is conducted, comparing fuel consumption, performance levels, and other factors. Even though the latter engine has a higher fixed operating cost, the advantages found in this study makes the Diesel motor a step forward of its competitor, whether concerning the flight hour cost or performance.
Diniz, Samuel Cunha, Henrique de Assis Coelho, Eduardo, Rodrigues de Oliveira, Gabriel, de Cardoso Oliveira, Lucas, Morais, Samuel Renan Costa, Vasques, Victor Britto, Jorge Machado, Luiz Henrique
Detecting Chemical Weapons Using Fourier Transform Infrared SpectroscopyTBMG-351659/1/2019
Chemical Warfare Agents (CWA) are a class of Weapons of Mass Destruction (WMD) designed to kill and injure humans through exposure to extremely toxic chemicals. In addition to CWA many chemicals used by industry, often referred to as Toxic Industrial Chemicals (TICS) can potentially be used by terrorists as weapons.
Fuel Consumption Saving Potential of Stirling Machine on Series Parallel Hybrid Electric Vehicle: Case of the Toyota Prius2018-01-04214/3/2018
Investigations on alternative fuels and new hybrid powertrain architectures have recently undergone significant efforts in the automotive industry, in attempt to reduce carbon emissions from passenger cars. The use of these fuels presents a potential for re-emerging the deployment of external combustion non-conventional engines in automotive applications, such as the Stirling engines, especially under the current development context of powertrain electrification. This paper investigates the potential of fuel consumption savings of a series-parallel hybrid electric vehicle (SPHEV) using a Stirling machine as fuel converter. An exergo-technological explicit analysis is conducted to identify the Stirling system configuration presenting the best compromise between high efficiency and automotive implementation constraints. The Stirling engine with combustion chamber preheater is prioritized. A SPHEV model is developed based on the Prius power-split hybrid electric architecture. Energy consumption simulations are performed on the worldwide-harmonized light vehicles test cycle (WLTC) using dynamic programing as global optimal energy management strategy. Results show improved fuel consumption performance of the Stirling machine compared to the ICE. In addition, the Stirling offers other intrinsic advantages such as low noise and vibration operation and mainly multi-fuel use capability. Consequently, the studied Stirling presents a potential for implementation on SPHEVs.
Bou Nader, Wissam, Mansour, Charbel, Nemer, Maroun, Dumand, Clement
SolidSense: Gas Analyzer on a ChipTBMG-283132/1/2018
The SolidSense sensor platform measures all EPA-regulated gas emissions (nitrogen oxides, carbon monoxide, and hydrocarbons), in addition to ammonia, with high accuracy and sensitivity. The chip-scale gas analyzer provides real-time diagnostics, and is suitable for monitoring emissions from diesel and gasoline engines, turbines, steam power plants, and other combustion technologies.
Alpha-STREAM ConvertorTBMG-271987/1/2017
Innovators at NASA’s Glenn Research Center have developed two novel technologies that make Stirling engines more efficient and less costly. First, Glenn’s thermoacoustic power converter uses sound to turn heat into electric power. Utilizing heat-driven pressures and volume oscillations from thermoacoustic sources to power piezoelectric alternators or other power-converter technologies, this device can generate electricity with unprecedented efficiencies. Unlike conventional Stirling-based devices, this thermoacoustic engine achieves high thermal-to-electrical efficiencies with no moving parts. Glenn’s second advancement for Stirling engines replaces the conventional linear alternator with a magnetostrictive alternator that converts the oscillating pressure wave into electric power (see figure). These innovations offer a reliable and efficient way to generate power from any heat source, benefiting applications such as combined heat and power (CHP) systems, distributed generation, solar power generation, and heating and cooling systems.
Mechanisms for Achieving Non-Sinusoidal Waveforms on Stirling EnginesTBMG-261491/1/2017
The current state-of-the-art Stirling engines use sinusoidal piston and displacer motion to drive the thermodynamic cycle and produce power. Research performed at NASA Glenn has shown that non-sinusoidal waveforms have the potential to increase Stirling engine power density, and could possibly be used to tailor engine performance to the needs of a specific application. However, the state-of-the-art Stirling engine design uses gas springs or planar springs that are very nearly linear, resulting in a system that resonates at a single frequency. This means that imposing non-sinusoidal waveforms, consisting of multiple frequencies, requires large forces from the drive mechanism (either the alternator or the crank shaft). These large forces increase losses, and increase the size and requirements of the control system. This innovation aims to reduce the external forcing requirements by introducing internal mechanical components that provide the forces necessary to achieve the desired waveforms.
Improving Stirling Engine Performance Through Optimized Piston and Displacer MotionTBMG-261521/1/2017
Stirling engines typically achieve high efficiency, but lack power density. Low power density prevents them from being used in many applications where internal combustion engines are viable competitors, and increases system costs in applications that require Stirling engines. This limits their operating envelope in both terrestrial and space applications. Sinusoidal piston and displacer motion is one of the causes of low power density. Previous work proposed solving this problem by replacing sinusoidal waveforms with waveforms that more closely approximate those of the ideal Stirling cycle. However, when working with real engines, imposing ideal waveforms has been shown to reduce power density and efficiency due to increased pressure drop through the regenerator and heat exchangers.
Internal Combustion Engine Handbook, 2nd English EditionR-4343/7/2016
More than 120 authors from science and industry have documented this essential resource for students, practitioners, and professionals. Comprehensively covering the development of the internal combustion engine (ICE), the information presented captures expert knowledge and serves as an essential resource that illustrates the latest level of knowledge about engine development. Particular attention is paid toward the most up-to-date theory and practice addressing thermodynamic principles, engine components, fuels, and emissions. Details and data cover classification and characteristics of reciprocating engines, along with fundamentals about diesel and spark ignition internal combustion engines, including insightful perspectives about the history, components, and complexities of the present-day and future IC engines. Chapter highlights include: • Classification of reciprocating engines • Friction and Lubrication • Power, efficiency, fuel consumption • Sensors, actuators, and electronics • Cooling and emissions • Hybrid drive systems Nearly 1,800 illustrations and more than 1,300 bibliographic references provide added value to this extensive study. “Although a large number of technical books deal with certain aspects of the internal combustion engine, there has been no publication until now that covers all of the major aspects of diesel and SI engines.” Dr.-Ing. E. h. Richard van Basshuysen and Professor Dr.-Ing. Fred Schäfer, the editors, “Internal Combustion Engines Handbook: Basics, Components, Systems, and Perpsectives”
Van Basshuysen, Richard, Schaefer, Fred
The Evolution of Automotive Technology: A HandbookR-43511/24/2014
This book covers one and a quarter century of the automobile, conceived as a cultural history of its technology, aimed at engineering students and all those who wish to have a concise introduction into the basics of automotive technology and its long-term development . Its approach is systemic and includes the behavior of drivers, producers, nonusers, victims, and other "stakeholders" as well as the discourse around mobility. Nowadays, students of innovation prefer the term co-evolution, emphasizing the parallel and mutually dependent development of technology and society. This acknowledges the importance of contingency and of the impact of the past upon the present, the very reason why The Evolution of Automotive Technology: A Handbook looks at car technology from a long-term perspective. Often we will conclude that the innovation was in the (re)arrangement of existing technologies. Since its beginnings, car manufacturers have brought a total of 1 billion automobiles to the market. We are currently witnessing an explosion toward the second billion. Looking back, we can see this history evolve through five distinctive phases: • Emergence (1880–1917) • Persistence (1917–1940) • Exuberance (1945–1973) • Doom (1973–2000) • Confusion (2001–present) The Evolution of Automotive Technology: A Handbook helps us understand how these phases impacted society and, in turn, shows us how car technology was influenced by car users themselves.
Mom, Gijs
Numerical Computational Optimization Applied To The Dynamic Behavior of an Articulated Cursor, Connecting Rod and Crank Mechanism - Case Studies for Implementing a Beta Stirling Engine2014-36-02829/30/2014
The Stirling engine is a device that has great potential for being used in applications where energy (heat) is available in the system. As an example, a Stirling motor can use the energy available in the gases from the combustion process of an automotive engine by using exhaust manifold as hot source. The Stirling motor consists of a piston that can move along a cylinder that is fulfilled by a working fluid and a displacer installed between the hot and cold chambers. Due to the large temperature difference between the chambers, it becomes feasible to use the corresponding energy to drive the Stirling engine. For design purposes, a multi-objective problem is formulated so that the maximization of thermodynamic efficiency, the minimization of energetic loss associated with the movement of the displacer set, and the minimization of energetic loss related to the fluid displacement between the two chambers is obtained for the optimal configuration of the system. To solve this optimal design problem, the Non- dominated Sorting Genetic Algorithm is used. The preliminary results demonstrated that the methodology proposed represents a promising approach for the design of Stirling engines. The theoretical results were used to construct a prototype of a Stirling engine for evaluating the whole design process.
de Paula Brito, Gelcino, Borges, José Antônio Ferreira
Automotive Fuels Reference Book, Third EditionR-2973/5/2014
The first two editions of this title, published by SAE International in 1990 and 1995, have been best-selling definitive references for those needing technical information about automotive fuels. This long-awaited new edition has been thoroughly revised and updated, yet retains the original fundamental fuels information that readers find so useful. This book is written for those with an interest in or a need to understand automotive fuels. Because automotive fuels can no longer be developed in isolation from the engines that will convert the fuel into the power necessary to drive our automobiles, knowledge of automotive fuels will also be essential to those working with automotive engines. Small quantities of fuel additives increasingly play an important role in bridging the gap that often exists between fuel that can easily be produced and fuel that is needed by the ever-more sophisticated automotive engine. This book pulls together in a single, extensively referenced volume, the three different but related topics of automotive fuels, fuel additives, and engines, and shows how all three areas work together. It includes a brief history of automotive fuels development, followed by chapters on automotive fuels manufacture from crude oil and other fossil sources. One chapter is dedicated to the manufacture of automotive fuels and fuel blending components from renewable sources. The safe handling, transport, and storage of fuels, from all sources, are covered. New combustion systems to achieve reduced emissions and increased efficiency are discussed, and the way in which the fuels’ physical and chemical characteristics affect these combustion processes and the emissions produced are included. There is also discussion on engine fuel system development and how these different systems affect the corresponding fuel requirements. Because the book is for a global market, fuel system technologies that only exist in the legacy fleet in some markets are included. The way in which fuel requirements are developed and specified is discussed. This covers test methods from simple laboratory bench tests, through engine testing, and long-term test procedures.
Richards, Paul
Evaluation of Performance and Emission Characteristics of an Unmodified Naturally Aspirated Compression Ignition Engine on Blends of Diethyl Ether and Diesel2013-01-288811/27/2013
The world today is majorly dependent upon fossil fuels for power generation, of which diesel forms an integral part. Diesel engines, having the highest thermal efficiency of any regular internal or external combustion engine, are widely used in almost all walks of life and cannot be dispensed with in the near future. However, the limited availability of diesel and the adverse effects of diesel engine emissions like nitrogen oxide (NOx) and soot particles raise serious concerns. Hence, their performance and emission improvement continues to be an avenue of great research activity. In this research work, the effects of blending Diethyl Ether with diesel in various proportions (5%, 10%, 15% and 20% by volume) were evaluated on engine performance and emissions of an industrial internal combustion engine. Several properties of DEE such as its low viscosity, high volatility, high cetane number, low auto ignition temperature and high solubility in diesel make it favorable for use in compression ignition engines. The data obtained from experimentation were carefully studied and a detailed theoretical analysis was carried out for each of the blends by comparing with baseline diesel performance data. The results were promising. The DEE blends showed a simultaneous decrease in carbon monoxide, unburned hydrocarbon, smoke emissions and brake thermal efficiency whereas the brake specific fuel consumption and the NOx emissions showed an increase. It was concluded that the 5% DEE-Diesel blend is the most effective combination from the performance and emission point of view.
Ahlawat, Vaibhav, Gupta, Mayank, Anand, Shaswat, Bansal, Vismit, Jain, Vibhor, Kumar, Naveen
Magnetostrictive AlternatorTBMG-1767411/1/2013
This innovation replaces the linear alternator presently used in Stirling engines with a continuous-gradient, impedance-matched, oscillating magnetostrictive transducer that eliminates all moving parts via compression, maintains high efficiency, costs less to manufacture, reduces mass, and eliminates the need for a bearing system.
The Inovar-Auto Program and its Influences on the Dual Fuel Engines Concepts based in Diesel Cycle2013-36-030210/7/2013
Brazilian government has started an incentive program for innovation and consolidation of the vehicles productive chain called INOVAR-AUTO. Many companies in the automobile industry are engaged in meeting the program targets that has a main scope in supporting the OEM's technology development, innovation, safety, environmental protection, energy efficiency and quality by providing taxes benefits for industrialized products. Considering this scenario, this paper will address the technological innovations applied in commercial vehicles segment focusing on dual fuel engines, a system operated by the injection of gas and diesel.
de Sousa Lourenço, Cléliomiro, de Sousa, Tiago, Pereira, André Luiz
Cascading Tesla Oscillating Flow Diode for Stirling Engine Gas BearingsTBMG-1484810/1/2012
Replacing the mechanical check-valve in a Stirling engine with a micromachined, non-moving-part flow diode eliminates moving parts and reduces the risk of microparticle clogging.
Temperature Controlled Exhaust Heat Thermoelectric Generation2012-01-12144/16/2012
The amount of energy wasted through the exhaust of an Internal Combustion Engine (ICE) vehicle is roughly the same as the mechanical power output of the engine. The high temperature of these gases (up to 1000°C) makes them intrinsically apt for energy recovery. The gains in efficiency for the vehicle could be relevant, even if a small percentage of this waste energy could be regenerated into electric power and used to charge the battery pack of a Hybrid or Extended Range Electric Vehicle, or prevent the actuation of a conventional vehicle's alternator. This may be achieved by the use of thermodynamic cycles, such as Stirling engines or Organic Rankine Cycles (ORC). However, these systems are difficult to downsize to the power levels typical of light-vehicle exhaust systems and are usually bulky. The direct conversion of thermal energy into electricity, using Thermoelectric Generators (TEG) is very attractive in terms of minimal complexity. However, current commercial thermoelectric modules based on Seebeck effect are temperature-limited, so they are unable to be in direct contact with the exhaust gases. A way to downgrade the temperature levels without significantly reducing the regeneration potential is to interpose Heat Pipes (HP) between the exhaust gas and the Seebeck modules in a controlled way. This control of maximum permissible temperature at the modules is achieved by regulating the pressure of phase change of the service fluid of the HP. In this way the system will be failsafe against overheating and will be able to operate efficiently under both low and high thermal loads. Such is the case of the range extender unit being developed by the team, which has a low (15 kW) and a high (40 kW) power mode of operation. Various designs concepts were evaluated by simulation, design and test. Although efficiencies were still moderate, it was possible to demonstrate the potential of this system for optimizing the output of commercially available temperature-limited TEGs.
P. Brito, Francisco, Martins, Jorge, Goncalves, L.M., Sousa, Rui
Novel Range Extender Concepts for 2025 with Regard to Small Engine Technologies2011-32-059611/8/2011
Energy politics and environmental circumstances demand novel strategies for private transport. Several studies have shown that one of these possibilities can be an electric vehicle with a range extender - REX. Today these REX engines are under way as derivation from modern internal combustion engines. As the need for an optimized usage of energy will further increase in the future, alternative energy converter systems have to be investigated. For DENSO, as supplier of components, it is of strong interest how the basic layout of these concepts could look like. This is necessary in order to be prepared for the specific needs of these concepts in terms of auxiliaries, electric / electronic components as well as for the cabin climate & various control strategies. In these REX-concepts all energies have to be considered. A sophisticated usage of energy inside a REX vehicle is required which leads to the investigation of a combined heat and power usage on-board. Using know-how and experience from small engine research and manufacturing, the range extender solutions can be treated in a very efficient and target-oriented way. Within this study alternative concepts using fossil energy as on-board power plants are being researched for the application in a range extender vehicle after 2025. Based on an analysis and derivation of requirements for upcoming scenarios high potential range extender solutions are investigated. As possible application mechanical energy generation as well as a combined heat-power generation is considered. In the following, a detailed examination of these high potential solutions is performed. This covers simulations and calculations of the necessary and relevant sections in order to generate know-how, identify crucial points, main issues and possible solutions.
Trattner, A., Pertl, P., Schmidt, St. P., Sato, Takaaki
A Liquid-Piston Steam Engine2011-28-013710/6/2011
Recently, waste heat recovery system from automobile exhaust gas has attracted a lot of attention as one of the promising technology to improve fuel efficiency and to reduce carbon dioxide emission. In order to put this system into practice, we developed a novel liquid-piston steam engine which has large potential of high efficiency, high reliability and low cost. Thermal efficiency of 12.7 % is achieved at temperatures of Th = 270 °C and l = 80 °C. Finally, electrical output of waste heat recovery system with the liquid-piston steam engine is estimated to be 44 or 79Wh under NEDC or HWFET modes, respectively.
Yatsuzuka, Shinichi, Oda, Shuzo, Niiyama, Yasunori, Fukuda, Kentaro, Nishizawa, Kazutoshi, Shikazono, Naoki
Review on the Fatigue Mechanisms in Automotive Valve Springs2011-36-000310/4/2011
This paper presents a review on the fatigue mechanisms in automotive valve springs manufactured on high-strength steel, as well as in other similar parts, like as helical suspension spring. The review was conducted with a phenomenological focus to support new developments in material for use in Otto and Diesel engines. Mechanical fatigue is a common process of damage that occurs in components subjected to cyclic loads, but in the particular case of valve springs, this problem is controlled through the project restriction, usually with the limitation of higher levels prescription of shear stress. In an attempt to increase this limit, allowing greater efforts at the elastic region the Material Engineering designs materials with higher toughness and the Manufacturing Engineering plays in the prevention or defects minimization, often inherent to the material. Considering this scenario, the proposal of austempered valve springs instead of the traditional quenched and tempered might assist in this challenge. Thus, this review presents a brief discussion about this theme, with the goal of supporting a search in progress using the austempered valve spring.
Serbino, Edison Marcelo, Tschiptschin, André Paulo
High Efficiency Internal Combustion Stirling Engine Development2011-01-04104/12/2011
A unique engine, based on the regenerative principle, is being developed with the goal of achieving high brake efficiency over a wide power range. It can be characterized as an internal combustion Stirling engine (ICSE). The engine is a split-cycle configuration with a regenerator between the intake/compression cylinder and the power/exhaust cylinder. The regenerator acts as a counter-flow heat exchanger. During exhaust, the hot gases are cooled by the regenerator. The regenerator stores this heat. On the next cycle, compressed gases flow in the opposite direction and are heated by the regenerator. The gases coming from the regenerator into the power cylinder are very hot (~900°C), which provides the necessary gas temperature for auto-ignition of diesel and other fuels. A simplified Air Cycle analysis of the ICS engine is presented to validate the concept thermodynamics and to show the inherent difference between the ICS and conventional internal combustion engine (ICE) indicated efficiency. The ICE engine indicated efficiency increases with increasing compression ratio and is insensitive to peak temperatures, whereas in the ICS engine indicated efficiency increases with decreasing compression ratio and increasing peak temperature. This engine concept is a candidate for application of adiabatic engine technology which has been explored for many years. With materials that can withstand high temperatures, brake efficiencies of 60-70% are possible. Low heat transfer is important to the proper operation of the engine. A multi-step cycle computer indicated thermodynamic and fluid flow model of the ICS engine of increasing detail was used during the engine development. Finally, detailed perturbation studies were conducted to fully understand the ICS design sensitivities. An engine friction model was added to the computer model to be able to compare estimates of ICSE BSFC and BMEP with ICE engines. Important ICS engine innovations include elimination of throttling losses, low friction due to low compression ratio, and very high air cycle efficiencies (~80%) combined with low compression ratio. The engine is designed for the highest possible efficiencies. In addition to these advantages, the engine has nearly constant pressure combustion, which should help reduce NOx formation. The major findings were: the ICS engine is more efficient than either gasoline or diesel engines over the entire operating range especially at part power. At wide open throttle, an ICS engine is more efficient than either a gasoline or a diesel engine. This advantage increases at part power. On the negative side, the ICS engine has inherent low power density (volumetric efficiency) because of low compression ratio, late air intake and late combustion. A prototype engine and a modest engine test dynamometer and instrumentation are nearing completion to demonstrate the P&B Enterprises, Inc. (PBEI), ICSE concept. The prototype is a retrofitted two-cylinder diesel engine. The prototype uses the existing engine block, and the crankshaft and camshaft fit into existing spaces in the block. Anticipated problems to be addressed with the prototype engine are starting, combustion characteristics, regenerator temperature control and high turbocharging ratios to achieve reasonable power density.
Patton, Richard, Bennett, George
Microfabricated Segmented-Involute-Foil Regenerator for Stirling EnginesTBMG-870511/1/2010
An involute-foil regenerator was designed, microfabricated, and tested in an oscillating-flow test rig. The concept consists of stacked involute-foil nickel disks (see figure) microfabricated via a lithographic process. Test results yielded a performance of about twice that of the 90-percent random-fiber currently used in small Stirling converters.
Feasibility Study of a Novel Combustion Cycle Involving Oxygen and Water2009-01-280811/2/2009
A novel combustion cycle which operates in 2-stroke operation and utilizes a novel exhaust valve timing and lift strategy is proposed to potentially replace the existing Otto and Diesel cycles. Air is replaced with oxygen to maximize the combustion efficiency and to enable broader range of fuels to be used. Water is injected into the combustion chamber to enhance the combustion heat absorption, gas expansion and to function as an energy carrier. Engine secondary heat that will otherwise be wasted to the environment is recovered and reused by the engine. Engine theoretical efficiency and out emissions are predicted to be improved.
Osman, Azmi
A Novel Concept for Combined Hydrogen Production and Power Generation2009-01-19466/15/2009
A novel concept of combined hydrogen production and power generation system based on the combustion of aluminum in water is explored. The energy conversion system proposed is potentially able to provide four different energy sources, such us pressurized hydrogen, high temperature steam, heat, and work at the crankshaft on demand, as well as to fully comply with the environment sustainability requirements. Once aluminum oxide layer is removed, the pure aluminum can react with water producing alumina and hydrogen while releasing a significant amount of energy. Thus, the hydrogen can be stored for further use and the steam can be employed for energy generation or work production in a supplementary power system. The process is proved to be self-sustained and to provide a remarkable amount of energy available as work or hydrogen. Furthermore, since the aluminum oxidation is completely GHG free and the alumina produced by the reaction can be recycled back to aluminum, the process has a sustainable environmental management. A preliminary design of the combined hydrogen production and power generation unit based on the aluminum combustion in water is proposed and the efficiency of the process is discussed in terms of both hydrogen production and power generation.
Franzoni, Federica, Milani, Massimo, Montorsi, Luca, Golovitchev, Valeri
New Reversible Air-conditioning Magnetocaloric System, Environmentally Friendly and Highly Energy Efficient2009-01-03134/20/2009
This paper presents a new system, environmentally friendly and energy efficient, based on a recent technological breakthrough: “magnetocaloric cooling around room temperature.” This new system is intended for “Automotive” applications to serve as reversible air conditioning and/or for keeping the pack-battery at desired temperature. This system replaces the classical compressor. The expected benefits are: increased energy efficiency (the coefficient of performance “COP” is increased), reduced consumption of fuel or electricity (electro-chemical battery, fuel cells), reduction of corresponding pollutant emissions and of any direct emission of pollutants. This cooling, heating and air conditioning system presents also a better protection of the atmosphere by removing all refrigerant gases. In this paper the magnetocaloric effect which is the scientific base of this new technology will be presented as well as magnetocaloric materials and magnetic systems. The specific magnetothermal heat exchange cycles used in automotive applications will also describe. The performance: the range of ambient temperatures and the temperature span between the “Hot” sink and the “Cold” sink, as well as the useful power (Cooling & Heating), the energy performance (COP) and the availability of components will also be presented and explained. Furthermore, a magnetocaloric demonstrator will be exposed and its first performance described.
Muller, Christian
Development of a Single-Fluid Consumable Infrastructure for Life Support Systems2007-01-32467/9/2007
Decomposition of high-grade hydrogen peroxide (H2O2) generates water vapor, oxygen, and heat. By converting heat to electrical energy with a Stirling engine, a spacesuit portable life support system can be maintained exclusively with H2O2; however, incorporation of additional cooling water may reduce the overall system mass. System components comprising the hydrogen peroxide portable life support system (HyPerPLSS) are discussed and analyzed. Component considerations and thermodynamic relations indicate an optimal hydrogen peroxide concentration of 95%. Life support requirements for eight hours of extravehicular activity are satisfied with 10.9 kg of liquid H2O2.
Lewandowski, Craig M., Akin, David L.
Design Concept for a Nuclear Reactor-Powered Mars RoverTBMG-17965/1/2007
A report presents a design concept for an instrumented robotic vehicle (rover) to be used on a future mission of exploration of the planet Mars. The design incorporates a nuclear fission power system to provide long range, long life, and high power capabilities unachievable through the use of alternative solar or radioisotope power systems. The concept described in the report draws on previous rover designs developed for the 2009 Mars Science laboratory (MSL) mission to minimize the need for new technology developments.
Study on Maximizing Exergy in Automotive Engines2007-01-02574/16/2007
The use of waste heat for automobile engine that applied Rankine cycle from the viewpoint of exergy (available energy) was researched. In order to recover heat to high quality energy, a heat-management engine whose exhaust port was replaced with an innovative evaporation device was developed. With this engine, high temperature and high pressure steam (400 degree C, 8MPa) could be generated from a large amount of the exhaust loss. In addition, high temperature water (189 degree C) was obtained from cooling loss. Consequently, the system that recovered more exergy from waste heat was established. To verify the system, the Rankine cycle system was installed in a hybrid vehicle and the automatic control system to change steam temperature and pressure according to the load variation was constructed. As the result of vehicle testing, thermal efficiency was increased from 28.9% to 32.7% (by 13.2% increase) at 100km/h constant vehicle speed. In this paper, it is concluded that Rankine cycle using waste heat was very effective to maximize exergy in automotive engine.
Endo, T., Kawajiri, S., Kojima, Y., Takahashi, K., Baba, T., Ibaraki, S., Takahashi, T., Shinohara, M.
Introduction to Engine ValvetrainsR-33910/27/2006
Many books have been written about the design, construction, and maintenance of valvetrains, but until now, information has been scattered and difficult to find. This comprehensive book will serve as your single resource providing a systematic introduction to valvetrain systems and components. Focusing on the fundamental concepts, this book enables you to appreciate design and material considerations, while at the same time understanding the difficulties in designing valvetrains to satisfy functional requirements and manufacturing challenges.
Wang, Yushu
Microscale Regenerative Heat ExchangerTBMG-618/1/2006
The device illustrated in Figure 1 is designed primarily for use as a regenerative heat exchanger in a miniature Stirling engine or Stirling-cycle heat pump. A regenerative heat exchanger (sometimes called, simply, a “regenerator” in the Stirling-engine art) is basically a thermal capacitor: Its role in the Stirling cycle is to alternately accept heat from, then deliver heat to, an oscillating flow of a working fluid between compression and expansion volumes, without introducing an excessive pressure drop. These volumes are at different temperatures, and conduction of heat between these volumes is undesirable because it reduces the energy-conversion efficiency of the Stirling cycle. Hence, among the desired characteristics of a regenerative heat exchanger are low pressure drop and low thermal conductivity along the flow axis.
AEI 2006 Tech AwardsAUTOAPR06_114/1/2006
The editors of Automotive Engineering International highlight some of the more innovative new products and technologies on display at the SAE 2006 World Congress, based on the latest information provided by exhibiting companies. The TurboDISI engine from FEV is a 1.8-L turbocharged gasoline direct-injection engine that offers impressive low-end torque and a fuel economy typically associated only with diesel engines. The engine, which can replace larger, heavier naturally aspirated engines, also promises reduced emissions compared to naturally aspirated and port-fuel-injected turbocharged engines. Compared to the larger 2.6-L naturally aspirated engine that it replaces, the TurboDISI engine produces the same peak torque and power, but reaches peak torque more quickly while offering better specific fuel consumption throughout the engine map. It minimizes the traditional turbo-lag drawback experienced by conventional turbocharged engines, which is characterized by a delay in the torque rise during acceleration, and applies technologies such as variable valve timing, an integrated charge air cooler in the intake manifold, and advanced charge air devices.
Thermoelectric Air/Soil Energy-Harvesting DeviceTBMG-52210/1/2005
A proposed thermoelectric device would exploit natural temperature differences between air and soil to harvest small amounts of electric energy. Because the air/soil temperature difference fluctuates between nighttime and daytime, it is almost never zero, and so there is almost always some energy available for harvesting. Unlike photovoltaic cells, the proposed device could operate in the absence of sunlight. Unlike a Stirling engine, which could be designed to extract energy from the air/soil temperature difference, the proposed device would contain no moving parts. The main attractive feature of the proposed device would be high reliability. In a typical application, this device would be used for low-power charging of a battery that would, in turn, supply high power at brief, infrequent intervals for operating an instrumentation package containing sensors and communication circuits.
The Linear Engine in 20042005-01-21405/11/2005
This study summarizes the work that has been done on the linear engine since it's invention. It attempts to highlight some of the major technologies, designs, and old and recent developments in the long history of the linear engine. In this paper, linear engines are grouped and studied from different standpoints such as internal or external combustion, 2-stroke vs. 4-stroke, number and arrangement of pistons, fuel type, the type of the machine the linear engine drives, depth of investigation, and the complexity of modeling the linear engine. This paper concludes that although simulation of the linear engine has been done with varying complexity and accuracy by several research groups and prototypes have run showing experimental results that predict higher efficiency for the linear engine than that of conventional engines, much work has to be done before the linear engine becomes commercially available.
Tóth-Nagy, Csaba, Clark, Nigel N.
Engine electronics come of ageOFHMAR05_013/1/2005
Changes in global standards, combined with engineering know-how, have resulted in a new generation of clean, quiet, and efficient engines. Engine electronics have been around for some time. So has the driving force behind their development, according to Ed Handley, Manager of Engine Electronics, International Truck and Engine. Handley and another coworker “actually started engine electronics here at International Engine back in the ‘80s,” he said. “We began by introducing electronics to a 6.9-L V8 engine for Ford. Emissions was a big driver, but we were also interested in features and performance.” Emissions? The EPA didn't start regulating diesel emissions until it crafted Tier 1 requirements in 1994. The phase-in of those standards began in 1996. “Back in the ‘80s it wasn't so much NOx levels,” said Handley. “It was the smoke that comes out of the tailpipe. It just doesn't look good when you take off and there's a plume of smoke. So we were generally trying to resolve those kinds of issues.” It was, he said, as much a matter of PR as EPA.
Ries, Richard
Internal Combustion Engine HandbookR-34512/6/2004
Thorough in its presentation, this essential resource illustrates the latest level of knowledge in engine development, paying particular attention to the presentation of theory and practice in a balanced ratio. Almost 950 pages in length - with 1,250 illustrations and nearly 700 bibliographical references - the Internal Combustion Engine Handbook covers all of this component's complexities, including an insightful look into the internal combustion engine's future viability.
Schaefer, Fred, Van Basshuysen, Richard
Potential of Rapeseed Oil as Diesel Engine Fuel2004-01-18586/8/2004
In order to achieve a sustainable society, vegetable oil derived from solar energy is a major topic of interest. Vegetable oils are can potentially be utilized as fuel in applications such as engines, gas turbines, furnaces, boilers and steam power plants. In this paper, rapeseed oil as a fuel for diesel engine was studied. There are seven refinement processes that improve the quality of the oil because the rapeseed oil is mainly produced for food. Rapeseed oil is produced from the raw material through compression, solvent extraction, degumming, deoxidation, bleaching, deodorization and a final-refinement process. However, all of these refinement processes are not necessary if the oil is to be used for diesel fuel. The performance of the engines operated by the tested fuels, which were extracted at the end of each of the seven refinement stages, was investigated. The major findings of this study are as follows. The brake thermal efficiency is unrelated to the refinement process and is almost equal to the performance with diesel fuel. Therefore, it is obvious that the tendency of CO2 emission is the same as that of the brake thermal efficiency. The THC emission, the NOx emission and the smoke density do not depend on the refinement processes of the rapeseed oil. The NOx emission and the smoke density level are almost equal to the situation when diesel fuel is used. In THC emission, all the tested fuels were lower than for the diesel fuel. The problem of deposits built-up in the combustion chamber is one which should be solved. Our overall conclusion is that all refinement processes can be omitted when the rapeseed oil is used as fuel in diesel engines.
Nishi, Kensuke, Korematsu, Koji, Tanaka, Junya
A Strategic Study - The Green and E-Commerce Impacts to Future Automotive Engine System R&D2003-01-23156/23/2003
IC engines have been the dominant automotive powertrain in the 20th century because of their advantages in power density, thermal efficiency, simplicity, durability and mobility. Condensing 100 years of information on automotive engine system technology evolution shows five different development stages: “bone and muscle”, “instinct”, “nerve and brain”, “intelligence”, and “system optimization”. Currently, the last step is facing the pressure of the “clean revolution” plus the “e-commerce revolution”. To meet future emission requirements and reduce CO2 emissions, the conventional engine system will be pushed to new physical limits, leading to higher cost and reduced durability. Therefore, the automobile industry should consider re-engineering or system optimization of the engines, including configuring the system architecture to be as transparent as possible to suit the fast changing environment of e-commerce. A hybrid powertrain is an ideal solution to meeting future fuel economy and emission regulations because it reduces much of the burden on the engine. From a system standpoint, the most important feature of a hybrid powertrain is the primary power unit, either IC engine or fuel cell, can be partially decoupled from the vehicle driving dynamic demands, yielding benefits such as zero-emission driving mode, no idling, no cold start emissions, no transient fuel compensation, easy control, simple engine calibration, etc. Furthermore, since heat engines and fuel cells cannot restore energy, a secondary energy system should be considered to recover braking energy. Finally, if the transient energy demand, including the initial launching, is taken care of by the electrical subsystem where no mass transfer problems exist, the overall system behaves more like a linear system and its control can be transparent and open. Implementation of all the new hybridization features that increase the likelihood of the system achieving the lowest emissions and highest fuel economy will lead many engine technologies to become obsolete. Correspondingly, the capital investment and engineering focus will be shifted, and the new system's open architecture will provide many opportunities for engine suppliers to improve the technology and cut costs quickly. This transparent system structure and its fast R&D response will change the engine product nature to more e-commerce styling.
Tang, Xiaoguo, Oltmans, Bret A., Natkin, Robert J.
Experimental Investigation on Emission Control in C.I.Engines Using Shrouded Inlet Valve2003-01-03503/3/2003
In today's modern world the internal combustion engine has a predominant role in stationary low power generation and a virtual monopoly in mobile applications. Concentrations emitted from the internal combustion engines thus build up to levels sufficient to have adverse effects on plants and animals. In Compression Ignition (CI) Engines turbulence of the charge plays a vital role in combustion process. The generation of suction swirl using a shrouded inlet valve is one way to achieve the desired level of turbulence. The shrouded inlet valve is capable of modifying the droplet size distribution of the fuel spray as well as producing a more ignitable and burnable mixture, which contributes to the reduction in the NOx content in the exhaust. The experimental part of the paper involves the fabrication of shrouded valves of different length of shroud. Load test and emission tests were carried out on a stationary four stroke C.I.Engine. The test results are analyzed and it is concluded that lower levels of emissions are achieved by shrouding. Even though there is a slight decrease in power output from the engine, the advantages of lowering the emission levels achieved through shrouding provides the basis for the trade off between power and emission.
Udayakumar, R., Valan Arasu, P., Sriram, S.
Fuel For Tomorrows Cars - Do We Have To Leave The Hydrocarbons?2001-01-324910/1/2001
The goal of all energy supply schemes for vehicles is to provide mechanical energy. Practical and economical reasons have made internal combustion engines the most sensible choice for many decades. Now the concern about adverse effects of the liberation of fossil carbon into earth's atmosphere gives the critics of IC-engines a new argument for their demand to switch to alternative fuels. It is shown, that all alternatives suffer from drawbacks. Hydrocarbons should be retained as the prominent energy carrier. In order to solve the CO2-problem, the carbon in these fuels should be of non-fossil origin. This requires the synthesis of hydrocarbons. It is possible to move gradually from a fossil supply base to a non-fossil one without taking the risk of any abrupt change.
Schindler, Volker
Very Advanced Automotive Powertrains with the Crankless Prime Movers2001-01-342110/1/2001
Comprehensive background and feasibility studies have been performed that show a novel very advanced automotive crankless prime mover, that is, a 2-, 4- or even 5-stroke thermodynamic cycle, twin-opposed-piston, crankless internal combustion engine (ICE), called the Fijalkowski engine-generator/motor (FE-G/M), has a great deal of potential in meeting and exceeding requirements for ride-by-wire (RBW) or x-by-wire (XBW) automotive mechatronic control system, comprizing drive-by-wire (DBW) all-wheel-drive-able (AWD) propulsion as well as brake-by-wire (BBW) all-wheel-brakeable (AWB) dispulsion mechatronic control hypo-systems for smart automotive vehicles (AV), most of all, for hybrid electric vehicles (HEV). The paper is focusing on main innovations and trends for a ride-by-wire (RBW) or x-by-wire (XBW) automotive mechatronic control system, comprising drive-by-wire (DBW) all-wheel-driveable (AWD) propulsion as well as brake-by-wire (BBW) all-wheel-brakeable (AWB) dispulsion mechatronic control hyposystems, and magneto-rheological fluid (MRF) mechatronic translational-motion-to-rotary-motion (TM-RM) & rotary-motion-to-rotary-motion (RM-RM) commutator prime mover, that is, the FE-G/M.
Fijalkowski, Bogdan
Using Artificial Neural Networks To Monitor Stirling EnginesTBMG-73084/1/2001
An important secondary topic addressed in the research and development effort described in the preceding article is the use of artificial neural networks to improve the monitoring and thus the control and safety of multiple free-piston Stirling engines. Information collected by monitoring subsystems constitutes essential feedback for use by control and safety subsystems. This information includes such externally measurable quantities as heater-head temperatures, motions of engine housings, and output currents and voltages.
Dynamic Balancing of Multiple Independent Stirling EnginesTBMG-73074/1/2001
Experiments have shown that an assembly of multiple free-piston Stirling engines can be designed and constructed in such a way as to both (1) make the vibrations of the engines balance each other to minimize the overall level of vibration, and (2) enable the engines to operate independently of each other, so that if one fails, the other(s) can continue to provide power. Prior to these experiments and to the research and development effort that preceded them, it was not possible to achieve both redundancy and suppression of vibrations: The only previously demonstrated method to balance out vibrations of multiple Stirling engines was by use of counter-oscillating pistons coupled to each other via a common thermodynamic hot space, with the engines driving linear alternators connected electrically in series. This older scheme precludes redundancy because the common thermodynamic interaction and the series electrical connection causes both engines to fail when one fails.
IAV's Steam Engine A Unique Approach to Fulfill Emission Levels from SULEV to ZEV2001-01-03663/5/2001
Fulfillment of SULEV standards without catalyst - this is a target engineers at IAV have been working on since the middle of the 1990s. The core of this development is an advanced steam engine with a high performance burner. This burner features extremely low raw pollutant emission. This paper describes new solutions that were found to solve the challenging tasks in the development of such an engine concept.
Buschmann, G., Haas, T., Hoetger, M., Mayr, B.
Contribution Feedstock and Fuel Transportation to Total Fuel-Cycle Energy Use and Emissions2000-01-297610/16/2000
In recent years, various alternative fuels have been proposed and studied for application in motor vehicles. Consequently, fuel-cycle analyses have been conducted to evaluate their energy and emissions effects. In a typical fuel-cycle analysis, feedstock recovery; feedstock transportation and storage; fuel production; and fuel transportation, distribution, and storage are examined. The general belief is that transportation and storage of feedstocks and fuels have small impacts on fuel-cycle results. However, no thorough studies have been conducted to confirm or disprove this belief. Transportation of feedstocks and fuels via different transportation modes requires use of various fuels and generates air pollutant emissions. Storage of liquid and gaseous fuels is subject to fuel losses, which also lead to air pollutant emissions. In fuel-cycle analyses, while feedstock recovery and fuel production have been studied carefully, transportation and storage of feedstocks and fuels are often not studied in detail. As part of a comprehensive fuel-cycle analysis at Argonne National Laboratory, we recently began to characterize transportation modes for different feedstock types, fuel types, production locations, and consumption locations. We collected data on the energy intensities of various transportation modes and the distances traveled for given feedstocks and fuels. We included five transportation modes - ocean tanker, barge, truck, rail, and pipeline - for various feedstocks and fuels. On the basis of the collected data, we estimated energy use and emissions associated with transportation and storage of gasoline, diesel, compressed natural gas, liquefied natural gas, liquefied petroleum gas, methanol, ethanol, gaseous and liquid hydrogen, and Fischer-Tropsch diesel. Our assessment indicates that, in some cases, transportation, storage, and distribution (T&S&D) can make a significant contribution to total fuel-cycle energy use and emissions for transportation fuels. For example, nitrogen oxide (NOx) emissions from T&S&D of gasoline, diesel, liquefied petroleum gas, dimethyl ether, Fischer-Tropsch diesel, and ethanol can comprise over 50% of total upstream emissions. Moreover, when fuel losses are taken into account, T&S&D can contribute over 60% of upstream VOC emissions for gasoline, diesel, liquefied petroleum gas, dimethyl ether, Fischer-Tropsch diesel, and methanol.
He, Dongquan, Wang, Michael
The Engine: a Perspective on Human Life and Environments2000-05-00106/3/2000
In the 17th century, Christiaan Huygens invented the first engine to save the labor, which is humanism. Nowadays, both gasoline (SI) and diesel (CI) engines hold the definite position as the prime mover of the current surface transport vehicles due to their superior power, energy density, and fuel economy. Although these engines give exceeding convenience to human life, they also have become the vanguard of environmental disruption. From this viewpoint, the author has tried to give a historical review and perspective on engine developments. Although it is said that further emission controls in CI engines are quite difficult, recent research work and prediction for both lower emissions and better fuel economy are discussed. It is concluded that CI engines will co-exist with SI engines in the future, part of which will be used in hybrid systems. Fuel cells will be widely utilized, and hydrogen internal combustion engines would be expected as well. The prime mover for the 21st century should be assessed in terms of resource depletion, human health impacts, and ecological impacts by using the LCA (Life Cycle Assessment) procedure. Future technology as well as the engine depends largely on politics and economics besides education and the information explosion.
Suzuki, Takashi
An Analysis of the Parallel Combustion Two-Stroke Engine2000-01-10223/6/2000
The Parallel Combustion Two-Stroke is an internal combustion engine utilizing a hypocycloid gear mechanism and parallel combustion chambers. The hypocycloid mechanism provides mechanical balance and linear rod motion which eliminates piston sidewall forces and creates two chambers in the working cylinder. These two chambers are connected to combustion chambers external to the working cylinder. The resulting engine operates on a two-stroke cycle with many of the advantages of a four-stroke engine. It operates as an internal combustion engine with many of the advantages of an external combustion engine. And it operates as a reciprocating engine with the dynamic balance of a rotary engine.
Rucker, Richard D.
Analytical Solution of Piston Ring Pack Lubrication for Truck Air Brake Compressor1999-01-376911/15/1999
This paper presents an analytical solution of piston ring pack lubrication for two-cylinder truck air brake compressor. A system of nonlinear equations with seven variables was developed to describe lubrication phenomena of the piston ring pack for both fully flooded and starvation conditions. The full mass conservation boundary conditions defined by JFO ([14],[15]) theory were employed for complete description of the cavitation algorithm with enclosed and open cavitation patterns. Impact of the piston ring design parameters such as offset, crown height, and tension on the oil transport, lubrication conditions and friction losses of the compressor were discussed in details.
Yu, B., Sawicki, J.T., Dunaevsky, V.
The Two-Stroke Rotary Diesel Engine1999-01-28888/17/1999
An innovative rotary engine uses a rotor that executes pendulum-like oscillatory rotation. This is converted into uniform rotation of the drive shaft by a simple mechanism. The new design is compact, lightweight and powerful. Simpler and cheaper fabrication, lower levels of noise and vibration, easier maintenance are among its advantages over the Wankel rotary engine and the Otto piston engine.
Shapovalov, Vladimir
A Study on Temperature Distribution of Stirling Engine Regenerator1999-01-25068/2/1999
The performance of Stirling engines depends on the performance of regenerators. Regenerators are primarily expected to have good temperature efficiency. In addition, the flow losses and dead space must be minimized. These factors, however, are in opposition to each other. Although a considerable amount of research has focused on these three factors, few studies have analyzed them in actual reciprocating flows. Moreover, it has not been possible to measure the temperature efficiency by using a working gas due to the rapid change of the gas temperature. Therefore, in this study, we measured the transition of the temperature in the reciprocating flows in a regenerator by using water instead of a gas and then examined the characteristics of the regenerator. Here, we report the observed transition of temperature, which almost coincided with results previously obtained by computer simulation.
Watanabe, Hiroichi, Fujisawa, Yuichi, Yoshida, Munenobu, Moriya, Shinji
Optimized Design of Stirling-Driven Vapor-Compression System1999-01-24538/2/1999
Stirling engines have many unique advantages including higher thermal efficiencies, preferable exhaust gas characteristics, multi-fuel usage, and low noise and vibration. On the other hand, heat pump systems are very attractive for space heating and cooling and industrial usage. There are several environmental merits of Stirling-driven vapor-compression (SDVC) systems. A design method for the SDVC, which is based on mathematical methods for Stirling and Rankine cycles, has been developed. The model treats a kinematic Stirling engine and a scroll compressor which are coupled by a belt. The measured performance of an actual system well agreed with the calculated results. The attractive SDVC performance using conventional and alternative refrigerants was shown. From the calculated Total Equivalent Warming Impact, TEWI and operating costs, it became clear that the SDVC system with the alternative refrigerant has a higher potential as the future air-conditioning system.
Kagawa, Noboru
Hydrogen Permeation Issue for Gas Fired AMTEC Systems1999-01-25578/2/1999
Diffusion of hydrogen in solids is an intriguing intellectual problem. Permeation of hydrogen generated in combustion into gas fired Alkali Metal Thermal to Electric Converter (AMTEC) systems can be detrimental to AMTEC performance for various reasons. Potential effects include depriming of the AMTEC cell arteries, blockage of the condenser and hydride formation. Numerous papers and reports have been published concerning hydrogen diffusion in solids (Birnbaum and Wert, 1972; Garber, 1975; Strehlow and Savage, 1974). Many of these papers concern the embrittling effects of hydrogen and many concern the diffusion process itself. Hydrogen permeation and permeation resisting strategies have been examined extensively in connection with other energy conversion technologies such as Stirling engines (Alger, 1988; Khalili etal., 1989) and high temperature heat pipes (Anderson et al., 1995; North and Anderson, 1997). Due to the different boundary conditions and materials involved, it was necessary to conduct experiments specifically designed for AMTEC to evaluate hydrogen permeation rates into AMTEC cells, to understand the effect of this permeation on AMTEC performance and finally, if hydrogen permeation turns out to be a cause for concern, to identify strategies to reduce permeation, and to design an AMTEC cell which will perform with adequate lifetime. This paper describes experiments and their results for AMTEC cells operated in a partial pressure of hydrogen. Experiments in which the hydrogen permeation rate across different thickness cell walls were measured with and without barrier coatings are also described. Due to greater sensitivity, the change in pressure on the vacuum side of the specimen was observed as hydrogen permeated the metal. Depending on the operating conditions and the operating life requirements of specific AMTEC systems, hydrogen permeation barriers may need to be included in the cell design. Some of the solution approaches that were implemented and their effectiveness in minimizing AMTEC degradation are also elucidated.
Mital, R., Butkiewicz, D. A., Childs, K. F., Hayes, D. D., Svedberg, R. C., Hunt, T. K.
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