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Technical Paper
2014-04-01
Maki Kawakoshi, Takanobu Kaneko, Toru Nameki
Abstract Controllability (C) is the parameter that determines the Automotive Safety Integrity Level (ASIL) of each hazardous event based on an international standard of electrical and/or electronic systems within road vehicles (ISO 26262). C is classified qualitatively in ISO 26262. However, no specific method for classifying C is described. It is useful for C classification to define a specific classification based on objective data. This study assumed that C was classified using the percentage of drivers who could reduce Severity (S) in one or more classes compared with the S class in which the driver did not react to a hazardous event. An experiment simulated a situation with increased risk of collision with a leading vehicle due to insufficient brake force because of brake-assist failure when the experiment vehicle decelerated from 50 km/h on a straight road. First, the relationship between the S class and the difference of speed at the moment of collision obtained in the experiment was classified according to ISO/DIS 26262 Part 3 Annex B.
Technical Paper
2014-04-01
Yohsuke Tamura, Masayuki Takeuchi, Kiyotaka Maeda, Noriaki Ohtsuka, Kenji Sato
The localized fire test provided in the Global Technical Regulation for Hydrogen Fuel Cell Vehicles gives two separate test methods: the ‘generic installation test - Method 1′ and the ‘specific vehicle installation test - Method 2′. Vehicle manufacturers are required to apply either of the two methods. Focused on Method 2, the present study was conducted to determine the characteristics and validity of Method 2. Test results under identical burner flame temperature conditions and the effects of cylinder protection covers made of different materials were compared between Method 1 and Method 2. The following results were obtained: (1) Methods 1 and 2 produced nearly identical results when the minimum temperature profile in the GTR test procedure was followed in both cases. (2) A steel protection cover on the cylinder significantly lowered cylinder surface temperatures during the fire test until activation of the thermal pressure relief device (TPRD). (3) A thermoplastic cover on the cylinder melted during the fire test and produced an engulfing pool fire during the localized fire portion of the test that accelerated activation of the TPRD.
Technical Paper
2014-04-01
Masashi Takahashi, Masayuki Takeuchi, Kiyotaka Maeda, Shouma Nakagawa
Electric vehicles have become more popular and may be involved in fires due to accidents. However, characteristics of fires in electric vehicles are not yet fully understood. The electrolytic solution of lithium-battery vehicles is inflammable, so combustion characteristics and gases generated may differ from those of gasoline cars. Therefore, we conducted fire tests on lithium-ion battery vehicles and gasoline vehicles and investigated the differences in combustion characteristics and gases generated. The fire tests revealed some differences in combustion characteristics. For example, in lithium-ion battery vehicles, the battery temperature remained high after combustion of the body. However, there was almost no difference in the maximum CO concentration measured 0.5 to 1 m above the roof and 1 m from the side of the body. Furthermore, HF was not detected in either type of vehicle when measured at the same positions as for CO. The experiment results did not reveal any reason to treat vehicles with lithium-ion batteries differently from gasoline vehicles with regard to safety measures against harmful gases that may be generated around the burning vehicle.
Technical Paper
2013-04-08
Yohsuke Tamura, Takeuchi Masayuki, Kenji Sato
Appropriate emergency response information is required for first responder before hydrogen fuel cell vehicles will become widespread. This paper investigates experimentally the hydrogen dispersion in the vicinity of a vehicle which accidentally releases hydrogen horizontally with a single volumetric flow of 2000 NL/min in the under-floor section while varying cross and frontal wind effects. This hydrogen flow rate represents normally a full throttle power condition. Forced wind was about maximum 2 m/s. The results indicated that the windward side of the vehicle was safe but that there were chiefly two areas posing risks of fire by hydrogen ignition. One was the leeward side of the vehicle's underbody where a larger region of flammable hydrogen dispersion existed in light wind than in windless conditions. The other was the area around the hydrogen leakage point where most of the leaked hydrogen remained undiffused in an environment with a wind of no stronger than 2 m/s.
Technical Paper
2013-04-08
Masashi Takahashi, Masaru Takabayashi, Hiroyuki Mitsuishi
ISO 12405-1,2 specifies international testing standards for lithium-ion batteries for vehicles. In the mechanical shock test is used to determine if the battery is damaged due to the shock imposed when the vehicle runs over a curb or similar minor accidents. Therefore, we conducted minor collision tests against a curb using an actual vehicle and compared the test results with the conditions specified in ISO 12405-1,2. The results confirmed that the impulse wave obtained using an actual vehicle within the range of the test in this study differs from the shape of the impulse wave specified in ISO 12405-1,2.
Technical Paper
2013-03-25
Hironori Suzuki, Tsuyoshi Katayama
In this study, a scheme for controlling the deceleration rate required to alleviate shockwave propagation in a vehicle platoon is proposed. Assuming a three-vehicle platoon, the deceleration rates of the 2nd and the 3rd vehicles were modeled so as to minimize the speed of the shockwave that propagates through the platoon. The effect of the decelerating two vehicles on a 4th following vehicle was also evaluated. Numerical analysis showed that an earlier and slightly more rapid deceleration rate significantly decreased the speed of the shockwave propagated by the first three vehicles. Furthermore, even though the shockwave was amplified through the 2nd to 4th vehicles, this negative effect could be eliminated by applying the same control strategy to the 3rd and 4th vehicles.
Technical Paper
2012-04-16
Motoyuki Akamatsu, HIroshi Hashimoto, Shinji Shimaoka
Seat belts for rear passengers are not commonly used, even though they can significantly reduce fatalities. A passenger seat belt reminder (PSBR) is installed in order to encourage seat belt use, but the effectiveness of PSBRs on the rear seat passenger has not yet been proven. We have developed a methodology to assess PSBR effectiveness. There are two pathways to encourage seat belt use. The first is that PSBR directly facilitates the passenger's use. The second is to motivate the driver request passengers to use seat belts. In the experiment, we asked participants sitting in the driver's seat to select one of five ranks of likelihood to encourage the passenger when a PSBR was presented. We also asked participants sitting in the rear passenger seat to select the rank of likelihood to use the belt voluntarily with PSBR and that to use the belt when the driver requested. The degree of likelihood was quantified by averaging the assigned percentage values to the ranks. The effectiveness of PSBR was estimated by summing the estimated percentage of passengers who used the seat belt voluntarily and the estimated percentage who had not used them voluntarily but did use them when the driver requested.
Technical Paper
2012-04-16
Yohsuke Tamura, Masaru Takabayashi, Masayuki Takeuchi, Nobuaki Ohtuka, Takashi Nakajima, Kenji Sato
We have developed a new propane burner that satisfies the requirements of localized fire test which was presented in SAE technical paper 2011-01-0251. This paper introduces the specifications of this burner and reports its characteristics as determined from various fire exposure tests that we conducted in order to gather data. These tests included temperature and heat flux distribution on cylinder surfaces, which would be useful for the design of automotive compressed fuel cylinders. Our fire exposure tests included localized and engulfing fire tests to compare TPRD activation time, cylinder burst pressure and other parameters between different flame configurations and tests to identify the effects of an automotive compressed fuel cylinder on localized fire test results.
Technical Paper
2011-08-30
Toshiyuki Hirose, Osamu Nakamura, Nobuhiro Okabe, Yukihiro Tsukasaki, Keiichi Koseki, Hiroshi Tsuda, Masashi Iizuka, Tadahide Sone, Hideaki Ando, Atsushi Kameoka, Hideki Komada, Makoto Hasegawa, Tatsuya Murakami, Mamoru Miyazaki
The study of 10% ethanol blended gasoline (E10 gasoline) utilization has been conducted in the Japan Auto-Oil Program (JATOP). In order to clarify the impact of E10 gasoline on vehicle performances, exhaust emissions, evaporative emissions, driveability and material compatibility have been investigated by using domestic gasoline vehicles including mini motor vehicles which are particular to Japan. The test results reveal that E10 gasoline has no impact on exhaust emissions, engine startup time and acceleration period under the hot start condition, but a slight deterioration is observed in some test cases under the cold start condition using E10 gasolines with 50% distillation temperature (T50) level set to the upper limit of Japanese Industrial Standards (JIS) K 2202. Regarding evaporative emissions, the tested vehicles shows no remarkable increase in the hot soak loss (HSL), diurnal breathing loss (DBL) and running loss (RL) testing with E10 gasolines.
Technical Paper
2011-08-30
Ken-ichi Okamoto, Takashi Kaneko, Tomoaki Kakihara, Keiichi Tsuchihashi, Masanori Okada, Kiminobu Hirata, Tsutomu Hasegawa, Yoshiro Egashira, Masahiko Shibuya, Keiichi Koseki, Toru Kawatani, Ken Matsuura, Kyouji Hosono, Mamoru Miyazaki
In Biodiesel Fuel Research Working Group(WG) of Japan Auto-Oil Program(JATOP), some impacts of high biodiesel blends have been investigated from the viewpoints of fuel properties, stability, emissions, exhaust aftertreatment systems, cold driveability, mixing in engine oils, durability/reliability and so on. This report is designed to determine how high biodiesel blends affect oil quality through testing on 2005 regulations engines with DPFs. When blends of 10-20% rapeseed methyl ester (RME) with diesel fuel are employed with 10W-30 engine oil, the oil change interval is reduced to about a half due to a drop in oil pressure. The oil pressure drop occurs because of the reduced kinematic viscosity of engine oil, which resulting from dilution of poorly evaporated RME with engine oil and its accumulation, however, leading to increased wear of piston top rings and cylinder liners. When a blend of 10% hydrogenated biodiesel (HBD) with diesel fuel is employed with 10W-30 engine oil, the pressure drop is smaller than that of 10-20% RME blends, because HBD has less heavy fraction compared to RME, and thus, even when diluting with engine oil, HBD can evaporate and is not apt to accumulate.
Technical Paper
2011-08-30
Tomoya Nakajo, Kenji Tsuchiya, Mitsuru Konno
The demands of application of dual-axis chassis dynamometers (4WD-CHDY) have increased recently due to the improvement of performance of 4WD-CHDY and an increase in the number of 4WD vehicles which are difficult to convert to 2WD. However, there are few evaluations of any differences between fuel economy and exhaust emission levels in the case of 2WD-CHDY with conversion from 4WD to 2WD (2WD-mode) and 4WD-CHDY without conversion to 2WD (4WD-mode). Fuel economy and exhaust emission tests of 4WD vehicle equipped with a typical 4WD mechanism were performed to investigate any differences between the case of the 2WD-mode and the 4WD-mode. In these tests, we measured ‘work at wheel’ (wheel-work) using wheel torque meters. A comparison of the 2WD-mode and the 4WD-mode reveals a difference of fuel economy (2WD-mode is 1.5% better than that of 4WD-mode) and wheel-work (2WD-mode is 3.9% less than that of 4WD-mode). However, there are almost no differences of exhaust emission levels. We found the difference of work of loss at tire (tire-loss-work) between the 2WD-mode and the 4WD-mode affects the difference of fuel economy.
Technical Paper
2011-05-17
Tetsuya Suzuki, Kazuki Shimamura, Yasumasa Maeda
It is becoming more and more necessary to achieve a sustainable low-carbon society by mobility not depending on oil. Electric vehicles are appropriate for such a society, but expensive battery cost and long charging time prohibit the promotion of EVs. One of the solutions is minimizing battery usage by ultra-low fuel efficiency, so we developed an ultrahigh-efficient electric commuter concept car “C-ta”, which requires as small a battery as possible. We assumed that drivers would use the car as a second car for short-distance daily use, such as commuting, shopping, transportation of family, etc. In order to improve fuel efficiency, we mainly considered an ultra-light weight body and chassis, to which CFRP (carbon fiber reinforced plastic) greatly contributes, ultra-low rolling resistance tires, and highly accurate vehicle control technology with four in-wheel motors. At last, the C-ta achieved ultra-low fuel efficiency of 25.3 km/kWh and a cruising distance of 125 km even if battery capacity is as little as 5 kWh.
Technical Paper
2011-04-12
Glenn W. Scheffler, Matt McClory, Michael Veenstra, Naoki Kinoshita, Hajime Fukumoto, Tommy Wei-Lii Chang, Marcel L. Halberstadt, Livio Gambone, Gini Sage
The SAE Fuel Cell Vehicle (FCV) Safety Working Group has been addressing FCV safety for over 11 years. In the past couple of years, significant attention has been directed toward a revision to the standard for vehicular hydrogen systems, SAE J2579(1). In addition to streamlining test methodologies for verification of Compressed Hydrogen Storage Systems (CHSSs) as discussed last year,(2) the working group has been considering the effect of vehicle fires, with the major focus on a small or localized fire that could damage the container in the CHSS and allow a burst before the Pressure Relief Device (PRD) can activate and safely vent the compressed hydrogen stored from the container. Even though there have been no incidents of localized fire causing failure of CHSS in FCVs or hydrogen vehicles, a few incidents of localized fire and subsequent container burst have occurred in Compressed Natural Gas (CNG) vehicles.(3,4) Given the potential severity of such an event, the Safety Working Group decided to address this potential failure mode by developing a new systems level test to demonstrate the performance of the CHSS in the specified fire conditions.
Technical Paper
2011-04-12
Yohsuke Tamura, MASARU TAKABAYASHI, Jinji Suzuki, Takashi Nohmi, Maya Maekawa, Kenji Sato
Hydrogen concentration during combustion in a confined space with a ceiling was investigated. The results indicated that steady-state hydrogen concentration was highest at the ceiling surface for all hydrogen flow rates. When hydrogen concentration was 10-20%, weak flame propagation occurred at the ceiling surface, with the most easily burnable spots being dented areas such as seams, pores and creases on the ceiling surface. The unstable and limited nature of flame propagation at the ceiling surface was attributed to the relationship between temperature and hydrogen concentration in a confined space.
Technical Paper
2010-11-03
David Lessley, Greg Shaw, Daniel Parent, Carlos Arregui-Dalmases, Matthew Kindig, Patrick Riley, Sergey Purtsezov, Mark Sochor, Thomas Gochenour, James Bolton, Damien Subit, Jeff Crandall, Shinichi Takayama, Koshiro Ono, Koichi Kamiji, Tsuyoshi Yasuki
The objective of the current study was to provide a comprehensive characterization of human biomechanical response to whole-body, lateral impact. Three approximately 50th-percentile adult male PMHS were subjected to right-side pure lateral impacts at 4.3 ± 0.1 m/s using a rigid wall mounted to a rail-mounted sled. Each subject was positioned on a rigid seat and held stationary by a system of tethers until immediately prior to being impacted by the moving wall with 100 mm pelvic offset. Displacement data were obtained using an optoelectronic stereophotogrammetric system that was used to track the 3D motions of the impacting wall sled; seat sled, and reflective targets secured to the head, spine, extremities, ribcage, and shoulder complex of each subject. Kinematic data were also recorded using 3-axis accelerometer cubes secured to the head, pelvis, and spine at the levels of T1, T6, T11, and L3. Chest deformation in the transverse plane was recorded using a single chestband. Following the impact the subject was captured in an energy-absorbing net that provided a controlled non-injurious deceleration.
Technical Paper
2010-10-25
Kenichi Akiyama, Akemi Nakayama
Aldehydes and ketones are known as one of the hazardous air pollutants. Usually, acidified 2,4-dinitrophenylhydrazine (DNPH) solution, or DNPH-impregnated cartridges are used for automotive exhaust carbonyls collection. Then, aldehydes and ketones combined with DNPH are analyzed by HPLC/UV (High Performance Liquid Chromatography/ Ultra Violet Detection). DNPH cartridge is used widely for a good point of the handling although handling of DNPH solution is not so convienient. However, the analytical result of acrolein using DNPH cartridge was known as the low reliability. Acrolein-DNPH is changed to acrolein-DNPH-DNPH in the cartridge with acid atmosphere before extraction. And then, acrorein-DNPH-DNPH is changed to acrorein-DNPH-DNPH-DNPH with an acid atmosphere. As a result of such chemical reaction before extraction, the acrolein-DNPH is detected to low concentration. We found that at the low temperature condition, acrolein-DNPH concentration decrease speed is held down. Then, we developed new automotive exhaust aldehydes and ketones collection method using conventional DNPH cartridge.
Technical Paper
2010-04-12
Kenichi Okamoto, Masaru Kohakura, Takashi Kaneko, Kazuki Fukuda, Katsuro Furui, Masanori Okada, Keiichi Tsuchihashi, Kiminobu Hirata, Hiromitsu Baba, Tsutomu Hasegawa, Akira Hozumi, Masahiko Shibuya, Kei-ichi Koseki, Toru Kawatani, Atsushi Kameoka, Kyouji Hosono
In Biodiesel Fuel Research Working Group(WG) of Japan Auto-Oil Program(JATOP), some impacts of high biodiesel blends have been investigated from the viewpoints of fuel properties, stability, emissions, exhaust aftertreatment systems, cold driveability, mixing in engine oils, durability/reliability and so on. In the impact on exhaust emissions, the impact of high biodiesel blends into diesel fuel on diesel emissions was evaluated. The wide variety of biodiesel blendstock, which included not only some kinds of fatty acid methyl esters(FAME) but also hydrofined biodiesel(HBD) and Fischer-Tropsch diesel fuel(FTD), were selected to evaluate. The main blend level evaluated was 5, 10 and 20% and the higher blend level over 20% was also evaluated in some tests. The main advanced technologies for exhaust aftertreatment systems were diesel particulate filter(DPF), Urea selective catalytic reduction (Urea-SCR) and the combination of DPF and NOx storage reduction catalyst(NSR). The analysis items were regulated exhaust gases such as CO, HC, NOx, PM, fuel consumption rate and unregulated exhaust emissions.
Technical Paper
2010-04-12
Yohsuke Tamura, Masaru Takabayashi, Jun-ichi Tomioka, Jinji Suzuki, Kenji Sato
To investigate the events that could arise when fighting fires in vehicles with carbon fiber reinforced plastic (CFRP) hydrogen storage cylinders, we conducted experiments to examine whether a hydrogen jet diffusion flame caused by activation of the pressure relief device (PRD) can be extinguished and how spraying water influences the cylinder and PRD. The experiments clarified that the hydrogen jet flame cannot be extinguished easily with water or dry powder extinguishers and that spraying water during activation of the PRD may result in closure of the PRD, but is useful for maintaining the strength of CFRP composite cylinders for vehicles.
Technical Paper
2010-04-12
Takashi Tagawa, Nobuyuki Uchida, Maki Kawakoshi, Masami Aga
Naturalistic driving data has been accumulated by driving data recorders to understand factors that contribute to collisions. Among the rear end conflicts at signalized intersections in the data, conflict data between the following vehicles and suddenly stopping lead vehicles were frequently observed just after their start. To investigate the following drivers' behavior in a realistic driving situation without collision danger, an instrumented vehicle equipped with a liquid-crystal display ahead of the windshield was developed, and an experiment reproducing such conflict on the display was conducted. It was found that a lead vehicle's rapid start (2.8 m/s₂ on average) before quitting its right turn caused the following vehicle's brake reaction time to be longer than a slow start (0.8 m/s₂ on average) did. This result suggests that a following driver's premature decision to start rapidly increases the risk of rear end collisions.
Technical Paper
2010-04-12
Glenn W. Scheffler, Michael Veenstra, Tommy Chang, Naoki Kinoshita, Matt McClory, Hajime Fukumoto, Jesse Schneider, Marcel Halberstadt
The SAE Fuel Cell Vehicle (FCV) Safety Working Group has been addressing FCV safety for over 10 years. The initial document, SAE J2578, was published in 2002. SAE J2578 has been valuable as a Recommended Practice for FCV development with regard to the identification of hazards associated with the integration of hydrogen and electrical systems onto the vehicle and the definition of countermeasures to mitigate these hazards such that FCVs can be operated in the same manner as conventional gasoline internal combustion engine (ICE)-powered vehicles. An update to SAE J1766 for post-crash electrical safety was also published in 2008 to reflect unique aspects of FCVs and to harmonize electrical requirements with international standards. In addition to SAE J2578 and J1766, the SAE FCV Safety Working Group also developed a Technical Information Report (TIR) for vehicular hydrogen systems (SAE J2579). The objective of this document was to define systems-level, performance-based requirements for vehicular hydrogen storage systems, particularly compressed hydrogen storage systems as most FCVs currently use this form of storage.
Technical Paper
2010-04-12
Takaaki Kitamura, Takayuki Ito
This paper proposes a new mixing-controlled, low temperature combustion (LTC) approach for high-speed direct injection (HSDI) diesel engines. The purpose of this approach is to avoid the excessively high pressure-rise rate (PRR) of premixed, kinetics-controlled LTC and to enable the low nitrogen oxides (NOx) combustion to operate over the wide speed and load range of the engine. To address the soot/noise trade-off at high load LTC operating conditions, the pressure modulated multiple-injection coupled with swirl control was applied. This injection strategy enables the injection of high pressure (HP) main spray into the local high temperature region of the already burning low pressure (LP) pilot spray injected from the neighboring injection hole. By employing this injection strategy, the equivalence ratio (φ) distribution of mixture is drastically varied during main combustion processes. The experimental results showed that by combining LP close-pilot injection, HP main injection near top dead center (TDC), and moderate swirl, the mixing-controlled LTC successfully achieve low engine-out NOx and soot emissions even at 13.7 bar IMEP while retaining high efficiency and low PRR.
Technical Paper
2009-04-20
Makoto Tsubokura, Takuji Nakashima, Kozo Kitoh, Yoshihiro Sasaki, Nobuyuki Oshima, Toshio Kobayashi
A numerical method specially designed to predict unsteady aerodynamics of road vehicle was developed based on unstructured Large-Eddy Simulation (LES) technique. The code was intensively optimized for the Earth Simulator in Japan to deal with the excessive computational resources required for LES, and could treat numerical meshes of up to around 120 million elements. Moving boundary methods such as the Arbitrary Lagrangian-Eulerian (ALE) or the sliding method were implemented to handle dynamic motion of a vehicle body during aerodynamic assessment. The method can also model a gusty crosswind condition. The method was applied to three cases in which unsteady aerodynamics are expected to be crucial.
Technical Paper
2009-04-20
Glenn W. Scheffler, Jake DeVaal, Gery J. Kissel, Michael Veenstra, Tommy Chang, Naoki Kinoshita, Matt McClory, Hajime Fukumoto, Marcel Halberstadt, Jesse Schneider
The SAE Fuel Cell Vehicle (FCV) Safety Working Group has been addressing FCV safety for over 9 years. The initial document, SAE J2578, was published in 2002. SAE J2578 has been valuable as a Recommended Practice for FCV development with regard to the identification of hazards and the definition of countermeasures to mitigate these hazards such that FCVs can be operated in the same manner as conventional gasoline internal combustion engine (ICE)-powered vehicles. SAE J2578 is currently being revised so that it will continue to be relevant as FCV development moves forward. For example, test methods were refined to verify the acceptability of hydrogen discharges when parking in residential garages and commercial structures and after crash tests prescribed by government regulation, and electrical requirements were updated to reflect the complexities of modern electrical circuits which interconnect both AC and DC circuits to improve efficiency and reduce cost. An update to SAE J1766 for post-crash electrical safety was also published in 2008 to reflect unique aspects of FCVs and to harmonize electrical requirements with international standards.
Technical Paper
2009-04-20
Nicholas A. White, Paul C. Begeman, Warren N. Hardy, King H. Yang, Koshiro Ono, Fusako Sato, Koichi Kamiji, Tsuyoshi Yasuki, Michael J. Bey
A total of eight low-speed, rear-end impact tests using two Post Mortem Human Subjects (PMHS) in a seated posture are reported. These tests were conducted using a HYGE-style mini-sled. Two test conditions were employed: 8 kph without a headrestraint or 16 kph with a headrestraint. Upper-body kinematics were captured for each test using a combination of transducers and high-speed video. A 3-2-2-2-accelerometer package was used to measure the generalized 3D kinematics of both the head and pelvis. An angular rate sensor and two single-axis linear accelerometers were used to measure angular speed, angular acceleration, and linear acceleration of T1 in the sagittal plane. Two high-speed video cameras were used to track targets rigidly attached to the head, T1, and pelvis. The cervical spine kinematics were captured with a high-speed, biplane x-ray system by tracking radiopaque markers implanted into each cervical vertebra. Vertebral angle time histories are reported for each biplane x-ray test.
Technical Paper
2008-10-06
Kazuki Fukuda, Masaru Kohakura, Takashi Kaneko, Katsuro Furui, Keiichi Tsuchihashi, Tsutomu Hasegawa, Kazuhisa Saitou, Hiromitsu Baba, Masahiko Shibuya, Osamu Nakamura, Masanori Okada, Kyouji Hosono, Kiminobu Hirata, Toru Kawatani, Gen Sugiyama
Biodiesel Fuel (BDF) Research Work Group works on identifying technological issues on the use of high biodiesel blends (over 5 mass%) in conventional diesel vehicles under the Japan Auto-Oil Program started in 2007. The Work Group conducts an analytical study on the issues to develop measures to be taken by fuel products and vehicle manufacturers, and to produce new technological findings that could contribute to the study of its introduction in Japan, including establishment of a national fuel quality standard covering high biodiesel blends. For evaluation of the impacts of high biodiesel blends on performance of diesel particulate filter system, a wide variety of biodiesel blendstocks were prepared, ranging from some kinds of fatty acid methyl esters (FAME) to another type of BDF such as hydrotreated biodiesel (HBD). Evaluation was mainly conducted on blend levels of 20% and 50%, but also conducted on 10% blends and neat FAME in some tests. The evaluation test items include balance point temperature (BPT), DPF regeneration rate, active regeneration control of DPF system, PM composition analysis, and so on.
Technical Paper
2008-04-14
Toshihiro Terada, Hiroshi Yoshimura, Yohsuke Tamura, Hiroyuki Mitsuishi, Shogo Watanabe
If a compressed hydrogen tank for vehicles is filled with hydrogen gas more quickly, the gas temperature in the tank will increase. In this study, we conducted hydrogen gas filling tests using the TYPE 3 and TYPE 4 tanks. During the tests, we measured the temperature of the internal liner surface and investigated its relationship with the gas temperature in the tank. We found that the gas temperature in the upper portion of the TYPE 4 tank rose locally during filling and that the temperature of the internal liner surface near that area also rose, resulting in a temperature higher than the gas temperature at the center of the tank. To keep the maximum temperature in the tank below the designed temperature (85°C) during filling and examine the representative tank internal temperatures, it is important to examine filling methods that can suppress local rises of tank internal temperature. First, we focused on the method for jetting hydrogen gas into the tank and conducted filling tests while varying the jet nozzle diameter of the TYPE 4 tank.
Technical Paper
2008-04-14
Eiji Kuroda, Noboru Yoshimura, Hisao Tagami, Masaru Yano, Shogo Watanabe, Masafumi Sasaki
The hydrogen consumption of fuel cell vehicles (FCV) can be measured by the gravimetric, pressure and flow methods within a ±1% error. These are the methods acknowledged by ISO and SAE [1, 2], but require the test vehicles to be modified in order to supply hydrogen from an external, rather than the onboard tank. Consequently, technical assistance of the vehicle manufacturer is necessary for this modification, while various components in the test vehicle must be readjusted. For these reasons, a measurement method free of vehicle modification is in great demand. The present study therefore developed an “oxygen balance method” which determines the amount of hydrogen that has reacted with oxygen in the fuel cell stack by measuring the oxygen concentration in exhaust gas. The results of evaluation tests indicated a good possibility of the oxygen balance method to achieve measurement of FCV fuel consumption while at the same time promising the simplicity of testing equipment and procedure comparable with the carbon balance method that is applied to the measurement of fuel consumption for internal combustion engine vehicles (ICEV).
Technical Paper
2008-04-14
Glenn W. Scheffler, Jake DeVaal, Gery J. Kissel, Jesse Schneider, Michael Veenstra, Tommy Chang, Naoki Kinoshita, George Nicols, Hajime Fukumoto
The SAE FCV Safety Working Group has been addressing fuel cell vehicle (FCV) safety for over 8 years. The initial document, SAE J2578, was published in 2002. SAE J2578 has been valuable to FCV development with regard to the identification of hazards and the definition of countermeasures to mitigate these hazards such that FCVs can be operated in the same manner as conventional gasoline internal combustion engine (ICE)-powered vehicles. J2578 is currently being updated to clarify and update requirements so that it will continue to be relevant and useful in the future. An update to SAE J1766 for post-crash electrical safety was also published to reflect unique aspects of FCVs and to harmonize electrical requirements with international standards. In addition to revising SAE J2578 and J1766, the Working Group is also developing a new Technical Information Report (TIR) for vehicular hydrogen systems (SAE J2579). The initial focus of this document is compressed hydrogen, as most FCVs currently use this form of storage.
Technical Paper
2007-10-29
Yoshio Tonegawa, Toru Nakajima, Nobuhiro Yanagisawa, Mitsuru Hosoya, Takeshi Shoji, Yasunori Iwakiri, Tetsuya Yamashita, Tomoaki Ikeda, Shigeyuki Tanaka, Ko Takahashi, Teruo Suzuki, Yasunori Sogawa, Hisaya Hattori
Crosscheck tests of fast electrical mobility spectrometers, Differential Mobility Spectroscopy (DMS) and Engine Exhaust Particle Sizer(EEPS), were conducted to evaluate the accuracy of fine particle measurement. Two kinds of particles were used as test particles for the crosscheck test of instruments: particles emitted from diesel vehicles and diluted in a full dilution tunnel, and particles generated by CAST. In the steady state tests, it was confirmed that the average concentration of each instrument was within the range of ±2σ from the average concentration of all the same type of instruments. In the transient tests, it is verified that the instruments have almost equal sensitivity. For application of the fast electrical mobility spectrometers to evaluation of particle number and size distributions, it is essential to develop a calibration method using reference particle counters and sizers (CPC, SMPS, etc.) and maintenance methods appropriate for each model. Furthermore, the accuracy of the instruments should be controlled using the methods developed on a daily basis.
Technical Paper
2007-10-29
Yasunori Sogawa, Hisaya Hattori, Nobuhiro Yanagisawa, Mitsuru Hosoya, Takeshi Shoji, Yasunori Iwakiri, Tetsuya Yamashita, Tomoaki Ikeda, Shigeyuki Tanaka, Ko Takahashi, Teruo Suzuki, Toru Nakajima, Yoshio Tonegawa
Newly designed laboratory measurement system, which reproduces particle number size distributions of both nuclei and accumulation mode particles in exhaust emissions, was developed. It enables continuous measurement of nano particle emissions in the size range between 5 and 1000 nm. Evaluations of particle number size distributions were conducted for diesel vehicles with a variety of emission aftertreatment devices and for gasoline vehicles with different combustion systems. For diesel vehicles, Diesel Oxidation Catalyst (DOC), urea-Selective Catalytic Reduction (urea-SCR) system and catalyzed Diesel Particulate Filter (DPF) were evaluated. For gasoline vehicles, Lean-burn Direct Injection Spark Ignition (DISI), Stoichiometric DISI and Multi Point Injection (MPI) were evaluated. Japanese latest transient test cycles were used for the evaluation: JE05 mode driving cycle for heavy duty vehicles and JC08 mode driving cycle for light duty vehicles. The results well indicated the particle number size distribution characteristics of each diesel aftertreatment technology and gasoline combustion system.
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