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Viewing 1 to 30 of 39975
2015-01-01
Technical Paper
2014-01-9053
Tobias Breuninger, Jürgen Schmidt, Helmut Tschoeke, Martin Hese, Andreas Kufferath, Frank Altenschmidt
The spray-guided combustion process offers a high potential for fuel savings in gasoline engines in the part load range. In this connection, the injector and spark plug are arranged in close proximity to one another, as a result of which mixture formation is primarily shaped by the dynamics of the fuel spray. The mixture formation time is very short, so that at the time of ignition the velocity of flow is high and the fuel is still largely present in liquid form. The quality of mixture formation thus constitutes a key aspect of reliable ignition. In this article, the spray characteristics of an outward-opening piezo injector are examined using optical testing methods under pressure chamber conditions and the results obtained are correlated with ignition behaviour in-engine. The global spray formation is examined using high-speed visualisation methods, particularly with regard to cyclical fluctuations. In order to characterise the recirculation zone of the hollow cone spray that is relevant to the ignition behaviour, laser-optical measuring methods were used.
2014-11-11
Technical Paper
2014-32-0063
Daniela Siano, Fabio Bozza, Danilo D'Agostino, Maria Antonietta Panza
In the present work, an Auto Regressive (AR) model and a Discrete Wavelet Transform (DWT) are applied on vibrational signals, acquired by an accelerometer placed on the cylinder block of an internal combustion engine, for knock detection purposes. To this aim, vibrational signals are acquired on a four cylinder Spark Ignition engine for different engine speeds and spark advances. The same analysis is executed by also using the traditional MAPO (Maximum Amplitude of Pressure Oscillations) index, applied on the in-cylinder pressure waveforms. The results of the three methods are compared and in depth discussed to the aim of highlighting the pros and cons of each methodology. In particular, the problem of fixing a constant threshold level for each running condition is afforded and solved. The examples presented show the capability of the vibration based detection algorithms in accurately monitor the presence of heavy or soft knock phenomena, and to determine its intensity. Therefore, the possibility of implementation in modern on-board control units is foreseen, as well.
2014-11-11
Technical Paper
2014-32-0073
Horizon Walker Gitano, Ray Chim, Jian Loh
Recent concern over air quality has lead to increasingly stringent emissions regulations on ever smaller displacement engines, resulting in the application of Electronic Fuel Injection to the 100cc-200cc class 2-wheelers in many countries. In the pursuit of ever smaller and less expensive EFI systems, a number of unique technologies are being explored, including resistive type oxygen sensors. In this paper we investigate the application of a small resistive oxygen sensor to a small motorcycle EFI system. Measurements of the exhaust system temperatures, and Air/Fuel Ratio ranges are carried out, and compared to the sensors response over this range to create an estimate of the sensors in-use performance. Actual sensor and temperature measurements are then compared to both a standard zirconia switching type oxygen sensor, and a wide-band oxygen sensor. Results are analyzed and indicate that the resistive type oxygen sensor should be capable of allowing the EFI controller to successfully control the vehicles AFR in all operating modes with a faster “light off” time, and lower overall current draw when compared to the standard heated zirconia sensor.
2014-11-11
Technical Paper
2014-32-0072
Kenta Sugimoto
Cost reduction is an important development goal for small motorcycles (1). As a way to reduce costs, we have developed an electronically controlled fuel injection (hereafter FI) system without a throttle position sensor (hereafter TPS). Ordinarily, the high throttle range is controlled and computed by TPS, and the low throttle range by manifold pressure sensor (hereafter MPS). The intake airflow is estimated with consistent high precision regardless of the engine load, and the basic fuel injection is executed accordingly. Also, transient correction monitors the size of TPS changes, to inject fuel immediately when a TPS change equal to or greater than a threshold value is detected. In our development, we replaced these functions with control by MPS. For calculation of basic fuel injection quantity by MPS, we carried on the conventional method. However, MPS transient correction control had some aspects with poor tracking. Thus, we constructed a new form of transient correction control, securing the following points. - To estimate changed intake airflow, we calculated the size of MPS value changes between the previous cycle and the current cycle in the crank intake stroke, securing precision. - We distributed the locations for transient correction into three before the completion of the intake stroke, making it possible to supply the calculated transient correction values to the current intake stroke regardless of the throttle input or engine state. - We subtracted the manifold pressure change due to engine speed fluctuation from the MPS change calculated at the transient correction execution positions, preventing unintended injection while lowering the threshold value for transient correction.
2014-11-11
Technical Paper
2014-32-0075
Kazuyoshi Shimatani
Various sensors including throttle position sensors (TPS), manifold pressure sensors (MPS), crank angle sensors, engine temperature sensors, and oxygen sensors are mounted in electronically controlled fuel injection (FI) systems to accurately regulate the air-fuel ratio according to the operating state and operating environment. Among these vehicle-mounted sensors, TPS has functions for detecting a fully-closed throttle and estimating intake air volume by the amount of throttle opening. Currently, we have conducted a study on transferring TPS functions into the MPS (manifold pressure sensor) in order to eliminate the TPS. Here we report on detecting a fully-closed throttle for achieving fuel cut control (FCC) and idle speed control (ISC) in fuel injection systems. We contrived a means for fully-closed throttle detection during ISC and controlling changes in the bypass opening during FCC in order to accurately judge each fully-closed throttle state via the manifold pressure. A factor in causing fluctuations in manifold pressure in a fully-closed throttle state are changes in the engine RPM (also referred to as engine speed) and changes in the degree of opening of the bypass (hereafter simply bypass opening).
2014-11-11
Technical Paper
2014-32-0079
Yuta Kugimachi, Yusuke Nakamura, Norimasa Iida
Homogeneous Charge Compression Ignition (HCCI) engine has several advantages of high thermal efficiency and low emission over the conventional Spark Ignition (SI) engine and Compression Ignition (CI) engine. Although one way to achieve higher loads without knocking in HCCI engine is the combustion phasing retard, it is difficult to control a combustion-phasing since there is no external combustion trigger for controlling ignition like spark ignition and diesel fuel injection. Futhermore, recent researches show that too much combustion-phasing retard leads to unacceptable cycle-to-cycle variation of Pressure Rise Rate (PRR) and Indicated Mean Effective Pressure (IMEP). Therefore, it is necessary to construct a HCCI combustion control system to control a combustion-phasing at constant phasing in the expansion stroke accurately to get the high load without knocking. This study investigates the HCCI combustion control system and the algorithm as a means of extending the limit of IMEP of HCCI combustion at high load for realize HCCI engine fuelled with Dimethyl Ether (DME).
2014-11-11
Technical Paper
2014-32-0078
Bo-Chiuan Chen, Yuh-Yih Wu, Wen-Han Tsai, Hsien-Chi Tsai, Huang-Min Lin, Yao-Chung Liang
Fuel film dynamics in the intake manifold are considered to develop air fuel ratio (AFR) control strategy with on-line system identification for a V2 engine in this paper. A1000 cc four-stroke two-cylinder, water-cooled port injection SI engine is used as the target engine to develop the engine model in Matlab/Simulink. The model which consists of charging, fueling, combustion, friction, and engine rotational dynamics is used to verify the proposed AFR control. Since the fuel film dynamics changes with different engine operating conditions, the fuel film parameters are often listed as look-up tables for fuel film dynamics calculation in the conventional AFR control. However, those parameters might be inaccurate during transient engine operation. Different intake port temperature will affect the accuracy of those fuel film parameters as well. In order to solve this problem, recursive least square (RLS) is used to identify those parameters on-line. Kalman filter is utilized to estimate the AFR using a narrow-band oxygen sensor.
2014-11-11
Technical Paper
2014-32-0099
Ken Naitoh, Daiki Ikoma, Hiroki Sagara, Taro Tamura, Taiki Hashimoto, Yoshiyuki Nojima, Masato Tanaka, Kentaro Kojima, Kenya Hasegawa, Takuya Nakai, Shouhei Nonaka, Tomoaki Kubota
In our previous reports based on computational experiments and fluid dynamic theory, we proposed a new compressive combustion principle for an inexpensive, lightweight, and relatively quiet engine reactor that has the potential to achieve thermal efficiency over 50% even for small combustion chambers having less than 100 cc. This level of efficiency can be achieved with colliding supermulti-jets that create complete air insulation to encase burned gas around the chamber center. The P-V diagram for this engine concept is between the Otto and Lenoir cycles. We originally developed two small prototype engine systems for gasoline. First one having one rotary valve for pulsating the intake flow and also sixteen nozzles of jets colliding is for examining combustion occurrence. As this prototype has no pistons, the bore size can be varied easily between about 50mm and 15mm. Experimental data basically indicates combustion occurrence. Next, we developed the second one having a strongly-asymmetric double piston system with the supermulti-jets colliding, although there are no poppet valves.
2014-11-11
Technical Paper
2014-32-0125
Mohd Al-Hafiz Mohd Nawi, Yoshiyuki Kidoguchi, Misato Nakagiri, Naoya Uwa, Yuzuru Nada, Seiji Miyashiro
High boosting technology is commonly applied to diesel engines in recent years. One the other hand, the study of spray behavior at ignition delay period is still an important role in diesel combustion. This study is focused on effect of ambient condition on diesel spray during ignition delay period. The study investigates both macro-scale and micro-scale dynamic behaviors of diesel spray affected by ambient density and temperature at early stage of injection. The experiment uses dual nano-spark shadowgraph method and rapid compression machine with constant volume chamber to understand dynamic behavior of evaporation diesel spray. This technique enables to capture images of both macro- and micro-scale structure of diesel spray using a still camera. Further, this system has two sparks that send high intensity light toward spray. When the sparks produce the luminescence at short time interval, images of the same diesel spray at different timing can be captured on separated films. The images show droplets formation, atomization and evaporation at spray boundary.
2014-11-11
Technical Paper
2014-32-0129
Giancarlo Chiatti, Erasmo Recco, Ornella Chiavola, Silvia Conforto
In the last years environmental issues of IC engines have promoted the need to assess new strategies in order to obtain a reduction not only of pollutants emission in atmosphere, but also of noise radiation. Engine noise can be classified into aerodynamic noise of intake and exhaust systems and surface radiated noise. Sources identification and analysis is essential to evaluate the individual contribution (injection, combustion, piston slap, turbocharger, oil pump, valves) to the overall engine noise with the aim of selecting appropriate noise reduction strategies. In previous papers, the attention was addressed towards the combustion related noise emission. The research activity was aimed at selecting the optimal placement for the microphone in which the signal was characterized by a strong correlation with the in-cylinder pressure development during the combustion process. The analysis and the processing of the sound emission allowed to isolate the acoustic contribution mainly due to the combustion event.
2014-11-11
Technical Paper
2014-32-0127
Hideyuki Ogawa, Gen Shibata, Yuhei Noguchi, Mutsumi Numata
Simultaneous reductions of NOx and particulate emissions as well as the improvements in the thermal efficiency and the engine performance with emulsified blends of water and diesel fuel are reported. A reduction in combustion temperature and promotion of premixing with larger ignition delays due to vaporization of the water in the fuel has been suggested as the mechanism. However, details of the combustion process and the mechanism of the emission reduction is not fully elucidated. In this research diesel like combustion of emulsified blend of water and diesel fuel in a constant volume chamber vessel was visualized with high speed color video and analyzed with a 2-D two color method. The shadowgraph images were also recorded and the rate of heat release was obtained from pressure data in the combustion chamber. An emulsified blend of water and diesel fuel (JIS. No. 2) with 26 vol% water and 4 vol% surfactant was used as the test fuel, and the diesel fuel in the emulsion without water and the surfactant was used as a reference.
2014-11-11
Technical Paper
2014-32-0135
Silvana Di Iorio, Agnese Magno, Ezio Mancaruso, Bianca Maria Vaglieco, Luigi Arnone, Lorenzo Dal Bello
The present paper describes the results of an experimental activity performed on a small diesel engine for quadricycles, a category of vehicles that is widespreading in Europe and is recently spreading over Indian countries. The engine is a prototype three-cylinder with 1000 cc of displacement and it is equipped with a direct common-rail injection system that reaches a maximum pressure of 1400 bar. The engine was designed to comply with Euro 4 emission standard that is a future regulation for these vehicles. It is worth underline that the engine can meet emission limits just with EGR system and an oxidation catalyst, without DPF. Various blends of biodiesels, 50%volume with diesel fuel, were tested; pure biofuels were also used. The investigation was performed at several engine speeds, at medium and full load, respectively. Combustion characteristics of biofuels were analysed by means of in-cylinder pressure and rate of heat release. Gaseous emissions were measured at the exhaust. A smoke meter was used to measure the particulate matter concentration.
2014-11-11
Technical Paper
2014-32-0134
Giovanni Bonandrini, Rita Di Gioia, Luca Venturoli, Domenico Papaleo, Lucio Postrioti, Leonardo Zappalà
Diesel engine technology is continuously focused on higher performances and lower fuel consumption. Reduced costs and lower emission levels are key factors in engine development too, in particular for small diesel engine, both for on-road and non-road application. Nowadays, common rail injection systems with electronic actuation of the injector are widely used in diesel engines, due to the high flexibility in terms of calibration and the possibility to use advanced injection strategies. In fact, in order to fulfill emission legislation requirements, to improve engine performance and to reduce fuel consumption, the amount and timing of the injected fuel have to be controlled with high precision. Nevertheless, conventional common rail systems are quite complicated mainly due to the complex indirect actuation of the injector, and the engine fuel consumption can be penalized in low and medium load conditions due to the recirculation of significant quantities of pumped fuel at high pressure.
2014-11-11
Technical Paper
2014-32-0132
Hiroki Ikeda, Norimasa Iida, Hiroshi Kuzuyama, Tsutomu Umehara, Takayuki Fuyuto
A combustion method called Noise Cancelling Spike (NC-Spike) Combustion has been reported in the co-author’s previous paper, which reduces combustion noise in pre-mixed charge compression ignition (PCCI) with split injection. This NC-Spike Combustion uses interference of the following “spike” of pressure rise (heat release) on the preceding peak of pressure rise. The overall combustion noise was reduced by lowering the maximum frequency component of the noise spectrum. The period of this frequency is two times of the time interval between the two peaks of the pressure rise rate. This maximum load range of conventional PCCI combustion is limited by the combustion noise, since the maximum pressure rise rate increases as the amount of injected fuel increases. The NC-Spike Combustion has a potential to extend of the operating range of PCCI combustion. In this paper, we investigates feasibility and controllability of the two-peak heat release rate during high temperature heat release by adding fuel in the adiabatic compression process of pre-mixed gas.
2014-11-11
Technical Paper
2014-32-0143
Ken Fosaaen
Global concerns over pollution have led to increasingly strict emissions legislation targeting small engines, which currently pollute at a much greater level than modern multi-cylinder automotive engines. Closed-loop control may be required to meet many future legislation requirements; however, such systems can be impractical due to high added component costs. A necessary component for closed-loop engine control is an oxygen sensor. Existing automotive oxygen sensors are too large, require too much power, and far too expensive to be suitable for the vast majority of the global small engine applications; therefore, some manufacturers have developed smaller and/or unheated versions based on their existing sensors to meet this emerging need. The ability to miniaturize resistive based sensors well below that of traditional Nernst (zirconia based) oxygen sensors affords the opportunity to meet future emissions standards with less of an impact on cost. The performance of a novel low-cost, low-power narrow-band oxygen sensor was compared with several automotive as well as newer oxygen sensors developed for the small engine market.
2014-11-11
Technical Paper
2014-32-0137
Ken Fosaaen
Global concerns over pollution have led to increasingly strict emissions legislation targeting small engines, which currently pollute at a much greater level than modern multi-cylinder automotive engines. Closed-loop control may be required to meet many future legislation requirements; however, such systems can be impractical due to high added component costs. A necessary component for closed-loop engine control is an oxygen sensor. Existing automotive oxygen sensors are too large, require too much power, and far too expensive to be suitable for the vast majority of the global small engine applications; therefore, some manufacturers have developed smaller and/or unheated versions based on their existing sensors to meet this emerging need. The ability to miniaturize resistive based sensors well below that of traditional Nernst (zirconia based) oxygen sensors affords the opportunity to meet future emissions standards with less of an impact on cost. In this study, a sub-miniature resistance-based narrowband oxygen sensor was developed and its response to various exhaust lambda values was characterized at various temperatures.
2014-11-11
Technical Paper
2014-32-0138
Tetsuya Osakabe
As gasoline prices have crept up in recent years, demand for higher fuel efficiency has increased also for motorcycles. Growing attention has been paid to how we can comprehensively improve fuel efficiency by raising the efficiency of the generator and other auxiliary equipment. This paper describes how we improved the power generation efficiency of a single-phase motorcycle generator of outer-rotor type by reducing electric losses (i.e. iron loss and copper loss) and improving magnetic flux through electromagnetic field analysis. Through electromagnetic field analysis, we first distinguished iron loss and copper loss. Then, focusing on the iron loss that we found inferiority, we modified the thickness and material of the stator core and improved power generation efficiency. Another source of iron loss was the non-magnetic protection cover of the magnets in the rotor. We reduced iron loss by drilling holes of that cover into where the magnet and the stator core faced each other and the magnetic flux passed through.
2014-11-11
Technical Paper
2014-32-0139
Ryutaro Shinohara
We have tentatively manufactured the prototype model of exhaust heat recovery heat exchanger and carried out the heat transfer and pressure drop performance tests on it. This prototype (P.T.) is characterized that the overall heat transfer coefficient is less affected by the change of the hot air mass flow rate than that of the mass-produced model (M.P.) and overall heat transfer coefficient of the prototype exceeds that of the mass-produced under the Rel range of 1500. We have found that the changes of overall heat transfer coefficient are caused by the variation of the thermal resistance of hot air side and the thermal resistance consists of the fin effective heat transfer coefficient and the tube hot air side heat transfer coefficient from equation of the thermal conductance. We have calculated the fin effective heat transfer coefficient using Pohlhausen equation and fin efficiency, and obtained the tube hot air side heat transfer coefficient from the test results. We have compared these coefficients and found that the fin effective heat transfer coefficient of the prototype is much lower, but the tube hot air side heat transfer coefficient of the prototype is much higher than that of the mass-produced.
2014-11-11
Technical Paper
2014-32-0048
Stefania Falfari, Claudio Forte, Federico Brusiani, Gian Marco Bianchi, Giulio Cazzoli, Cristian Catellani
Faster combustion and lower cycle-to-cycle variability are the two mandatory tasks in the naturally aspirated engines for lowering the emission levels and for increasing the efficiency. Generally speaking the promotion of a stable and coherent tumble structure is largely believed in literature to enhance the in-cylinder turbulence accelerating combustion process. In small PFI engine layout and weight constraints limit the adoption of more advanced concepts. The turbulence generation process is strictly related to the tumble vortex deformation process: during the compression stroke the tumble vortex is deformed, accelerated and its breakdown in smaller eddies leads to the turbulence enhancement process. The prediction of the final level of turbulence for a particular engine operating point is crucial during the engine design process because it represents a practical comparative means for different engine solutions. The tumble ratio parameter value represents a first step toward the evaluation of the turbulence level at ignition time, but it has an intrinsic limit.
2014-11-11
Technical Paper
2014-32-0041
Luigi Allocca, Alessandro Montanaro, Rita Di Gioia, Giovanni Bonandrini
In the next future, improvements of direct injection systems for spark-ignited engines are necessary for the potential reductions in fuel consumptions and exhaust emissions. The admission and spread of the fuel in the combustion chamber is strictly related to the injector design and performances, such as to the fuel and environmental pressure and temperature conditions. In this paper the spray characterization of a GDI injector under normal and flash-boiling injection conditions has been investigated. A customized sensing of the injector nose permitted the temperature control of the nozzle up to 90 °C while a remote-controlled thermostatic device allowed the fuel heating from ambient to 120 °C. An axially-disposed, 0.200 mm in diameter, single-hole injector has been used with l/d ratio equal to 1 and static flow@100 bar: 2.45 g/s, using iso-octane as mono-component fluid. A 1.0 ms duration single pulse strategy has been adopted at the injection pressure of 10 MPa. The spray evolved in a quiescent optically-accessible vessel pressurize at 0.05, 0.1 and 0.3 MPa at ambient temperature of the gas (N2).
2014-11-11
Technical Paper
2014-32-0042
Bernard Alsteens
Automotive design is going through one of its most profound changes. Fuel prices and growing environmental concerns have made efficiency the biggest prerogative in vehicle design. Manufacturers of hybrid, electric and conventionally-powered vehicles are experimenting with new designs and materials to decrease weight, or mass, and improve economy. In fact reducing mass is where today’s efficiency battle is being fought. Composite materials can bring significant weight saving in the design. These materials are one of the solutions offered to the designers to achieve new fuel efficiency regulation. New challenge arises in term of design optimization and manufacturing. Shifting from a metal to composite paradigm requires a dedicated tool for composite design in order to take into account the specific composite behavior. Material performance varies widely over the entire part mainly due to the process and the corresponding microstructure. Classical design tools are not able to describe accurately the local composite material behavior, leading to introduction of safety factors and lack of confidence in the design.
2014-11-11
Technical Paper
2014-32-0012
Yoshimoto Matsuda
As for electric automobile, the mass production period has begun by the rapid progress of the battery performance. But for the electric motor cycle(MC), it is limited for the venture companies’ releases. To study the feasibility of the electric MC, we developed the prototypes in the present technical and suppliers’ environments and evaluated them by the practical view points. The developed electric MC has the equivalent driving performance of the 250cc inner combustion engine(ICE) MC and a cruising range of 100km in normal use. In the prototype development, the reliability and the ability of protection design of the battery in the whole vehicle against the environmental loads are mainly studied, especially, fever and cold, water, shock, and the accident impact. In addition, it is carried out the performance improvement by the heat management design of the motor to meet the practical use condition. From the usage points as MC, we developed the function of the 4-speeds dog gear MT and its electric control, reward ride function, the regenerative brake control, and the quick charge.
2014-11-11
Technical Paper
2014-32-0013
Stefano Frigo, Gianluca Pasini, Silvia Marelli, Giovanni Lutzemberger, Massimo Capobianco, Paolo Bolognesi, Roberto Gentili, Massimo Ceraolo
As a result of growing environmental concerns, in the last years more stringent regulations for vehicle fuel consumption and exhaust emissions have been developed. Car manufacturers have focused their attention on developments of hybrid configurations of their conventional vehicles. To this aim, advanced powertrains for efficient utilization of energy are adopted in order to recover energy release during braking and, as well, to enable the ICE to operate within its highest efficiency region. Additionally, depending on the hybrid powertrain architecture (i.e., series hybrid, parallel hybrid, range extended, etc.), the ICE can also be significantly downsized thus reducing fuel consumption. The application of a turbocharging system allows to further downsize the ICE, still keeping a reasonable power level. Besides, the possibility to couple an electric drive to the turbocharger (electric turbo compound) to recover the residual energy of the exhaust gases is becoming more and more attractive, as demonstrated by several studies in the open literature and by the current application in the F1 Championship.
2014-11-11
Technical Paper
2014-32-0071
Christian Schweikert, David Witt, Dirk Schweitzer, Marco Nicolo, Liu Chen
Abstract The market potential for products such as scooters and small motorcycles is already self-sustaining. However, other applications for small engines can be more fragmented with a wide variety of requirements for the engine control unit. Consequently, the engine control unit can be designed to accommodate more features than are necessary for a given application to cover a broader market. The flip side of this approach is to design the engine control unit for a limited application reducing the market size. Neither approach creates a cost efficient product for the producer. It either supplies the market with an electronic control unit that has features not being utilized (wasted costs) or a unit that has limited capabilities reducing the economies of scale (higher costs). When these designs are developed using discrete components these inefficiencies are exacerbated. Integration of these functions at the semiconductor level can mitigate these costs, improve the thermal performance and expand the functional capabilities to include additional vehicular control aspects in the electronic control unit.
2014-11-11
Technical Paper
2014-32-0084
Eiji Kinoshita, Akira Itakura, Takeshi Otaka, Kenta Koide, Yasufumi Yoshimoto, Thet Myo
Abstract In order to improve the cold flow properties of coconut oil biodiesel and to reduce the lifecycle CO2 emission by using bio-alcohol at biodiesel manufacturing, varying the types of alcohol used at transesterification was examined. The pour point of coconut oil ester decreases as the carbon number of alcohol increases. Among 5 ester fuels, the pour point of coconut oil isobutyl ester (CiBE) made from isobutanol is lowest, −12.5 °C, compared to that of coconut oil methyl ester (CME), highest, −5 °C. The pour point of coconut oil 1-butyl ester (CBE) is −10 °C, second lowest. Furthermore, CBE, CiBE, CME and JIS No.2 diesel fuel (gas oil) were tested using a DI diesel engine. CBE and CiBE have shorter ignition delay compared to the gas oil although slightly longer than CME. CBE and CiBE have the same thermal efficiency and NOx emissions compared to the gas oil. HC, CO and Smoke emissions of coconut oil ester fuels slightly increase when the ester molecule carbon number increases. However, these exhaust emissions are lower than that of the gas oil.
2014-11-11
Technical Paper
2014-32-0086
Yasufumi Yoshimoto, Eiji Kinoshita, Kazuyo Fushimi, Masayuki Yamada
Abstract This paper describes the influence of different kinds of FAME (fatty acid methyl ester) on the smoke emissions of a small single cylinder DI diesel engine and the soot formation characteristics in suspended single droplet combustion. The study used eight kinds of commercial FAME and diesel fuel blends. The tested FAMEs are saturated fatty acids with 8 to 18 carbon molecule chains, and with three different double bonds with C18. The results show that with all the FAME mixtures here, the brake thermal efficiencies with the FAME-diesel fuel blends were similar to neat diesel fuel operation while the smoke emissions with all of the tested FAME-diesel fuel blends were lower. To examine the differences in the soot formation characteristics, measurements of the formed soot mass were also performed with a basic experimental technique with suspended single droplet combustion. The soot was trapped on a glass fiber filter, and the mass of the filter was measured with an electronic microbalance.
2014-11-11
Technical Paper
2014-32-0090
Jeffrey Blair, Glenn Bower
Abstract Operation of snowmobiles in national parks is restricted to vehicles meeting the Best Available Technology standard for exhaust and noise emissions as established by the National Parks Service. An engine exceeding these standards while operating on a blend of gasoline and bio-isobutanol has been developed based on a production four-stroke snowmobile engine. Miller cycle operation was achieved via late intake valve closing and turbocharging. The production Rotax ACE 600cc 2 cylinder engine was modeled using Ricardo WAVE. After this model was validated with physical testing, different valve lift profiles were evaluated for brake specific fuel consumption and brake power. The results from this analysis were used to determine a camshaft profile for Miller cycle operation. This was done to reduce part load pumping losses and increase engine efficiency while maintaining production power density. A catalytic converter was added to reduce exhaust gas emissions, as measured by the EPA 40 CFR Part 1051 5-mode emissions test cycle.
2014-11-11
Technical Paper
2014-32-0114
Enrico Mattarelli, Carlo Alberto Rinaldini, Giuseppe Cantore, Enrico Agostinelli
The paper compares two different design concepts for a range extender engine rated at 30 kW at 4500 rpm. The first project is a conventional 4-Stroke SI engine, 2-cylinder, equipped with port injection and a 3-way catalyst. The second is a new type of 2-Stroke loop scavenged SI engine, featuring a direct gasoline injection and a patented rotary valve for enhancing the induction and scavenging process. Air is delivered to the 2-stroke engine by means of a piston pump, arranged as a second cylinder, with its axis at 90° from the main one. In this way, the crankcase and the crankshaft of both analyzed engines may be almost identical, despite the different operating cycle. The combustion system of the 4-Stroke engine is a conventional 4-valve pentroof design, while the 2-Stroke engine has got a hemispheric dome, with close-spaced spark plug and injector. The only valve installed on the 2-Stroke engine is the patented rotary valve, revving at the same speed of the engine. Both power units have been virtually designed with the help of CFD simulation.
2014-11-11
Technical Paper
2014-32-0112
Christian Zinner, Reinhard Stelzl, Stephan Schmidt, Stefan Leiber, Thomas Schabetsberger
There are several reasons for equipping an internal combustion engine with a turbo charger. The most important motivation for motorcycle use is to increase the power to weight ratio. Additionally, the importance of reducing CO2-emissions is increasing even for power sport applications. These two motives, the CO2 reduction on the one hand and the increase of the power to weight ratio on the other hand, were the main drivers for the presented investigation. Focusing on the special boundary conditions of motorcycles, like the wide engine speed range or the extraordinarily high demands on response behavior, automotive downsizing technologies cannot be transferred directly to this field of application. This led to the main question: Is it possible to design a turbo charged motorcycle engine with satisfactory drivability and response behavior? The layout of a charged motorcycle engine, as presented in two previous papers, was derived by simulation and had to be verified by experimental investigations.
2014-11-11
Technical Paper
2014-32-0004
Yuma Ishizawa, Munehiro Matsuishi, Yasuhide Abe, Go Emori, Akira Iijima, Hideo Shoji, Kazuhito Misawa, Hiraku Kojima, Kenjiro Nakama
Abstract One issue of Homogeneous Charge Compression Ignition (HCCI) engines that should be addressed is to suppress rapid combustion in the high-load region. Supercharging the intake air so as to form a leaner mixture is one way of moderating HCCI combustion. However, the specific effect of supercharging on moderating HCCI combustion and the mechanism involved are not fully understood yet. Therefore, experiments were conducted in this study that were designed to moderate rapid combustion in a test HCCI engine by supercharging the air inducted into the cylinder. The engine was operated under high-load levels in a supercharged state in order to make clear the effect of supercharging on expanding the stable operating region in the high-load range. HCCI combustion was investigated under these conditions by making in-cylinder spectroscopic measurements and by analyzing the exhaust gas using Fourier transform infrared (FT-IR) spectroscopy. The results revealed that cool flame reactions were induced by increasing boost pressure when gasoline with a Research Octane Number of approximately 91 was used as the test fuel.
Viewing 1 to 30 of 39975