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Technical Paper

Thermal Behavior in Hydrogen Storage Tank for FCV on Fast Filling (2nd Report)

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.
Technical Paper

Study on Reliable Automotive Exhaust Acrolein Collection Method

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.
Technical Paper

Safety Evaluation on Fuel Cell Stacks Fire and Toxicity Evaluation of Material Combustion Gas for FCV

Fuel cell vehicles represent a new system, and their safety has not yet been fully proved comparing with present automobile. Thorough safety evaluation is especially needed for the fuel system, which uses hydrogen as fuel, and the electric system, which uses a lot of electricity. The fuel cell stacks that are to be loaded on fuel cell vehicles generate electricity by reacting hydrogen and oxygen through electrolytic polymer membranes which is very thin. The safety of the fuel and electric systems should also be assessed for any abnormality that may be caused by electrolytic polymer membranes for any reasons. The purpose of our tests is to collect basic data to ultimately establish safety standards for fuel cell stacks. Methanol pool flame exposure tests were conducted on stationary use fuel cell stacks of two 200W to evaluate safety in the event of a fire.
Technical Paper

Regional Trade and Emission Gas in Asian Automobile Industry

This paper is an attempt to estimate the traffic demand of private vehicles in the Philippines and Thailand toward 2030. Estimation of road traffic volume is one of the most important elements for determining fuel consumption and emission gas levels. The level of passenger car ownership is still low, but there has been a distinct shift toward passenger cars due to the lack of mass transport. In Asian countries, inspection and maintenance and emission standards are the most important policy measures. The projections of car stock are evaluated as the emissions of PM, CO and NOx by applying these policy measures in the case of Thailand.
Journal Article

Prediction of Spray Behavior in Injected by Urea SCR Injector and the Reaction Products

In the urea SCR system, urea solution is injected by injector installed in the front stage of the SCR catalyst, and NOx can be purified on the SCR catalyst by using NH3 generated by the chemical reaction of urea. NH3 is produced by thermolysis of urea and hydrolysis of isocyanic acid after evaporation of water in the urea solution. But, biuret and cyanuric acid which may cause deposit are sometimes generated by the chemical reactions without generating NH3. Spray behavior and chemical reaction of urea solution injected into the tail-pipe are complicated. The purpose of this study is to reveal the spray behavior and NH3 generation process in the tail-pipe, and to construct the model capable of predicting those accurately. In this report, the impingement spray behavior is clarified by scattered light method in high temperature flow field. Liquid film adhering to the wall and deposit generated after evaporation of water from the liquid film are photographed by the digital camera.
Technical Paper

Potential of Nanoparticle Formation by Vehicles

For the better understanding of nanoparticles observed on the rode side, adding to the emission test on the chassis dynamometer and engine dynamometer test, possible factors for formation of nanoparticles are investigated. As other possible factors, cold starting of transient test cycle, blow-by gas from heavy duty diesel engine without a positive crankcase ventilation, exhaust braking, and plume mixing of vehicle exhausts were investigated. Nuclei mode particles under the transient test cycles formed during fuel cut period, fuel enrichment period and idling period. Concentration of nuclei mode particles during the idling period are depends on exhaust temperature. The higher exhaust temperature courses the lower number concentration but variation range is within twice. Emission rate of nanoparticles from blow-by gas is one thousandth of tail pipe emissions rate and was found to be negligible.
Technical Paper

Oxidation Degradation and Acid Generation in Diesel Fuel Containing 5% FAME

Compared with diesel fuel, FAME is relatively unstable and readily generates acids such as acetic acid and propionic acid. When FAME-blended diesel fuel is used in existing diesel vehicles, it is important to maintain the concentration of FAME-origin acid in the fuel at an appropriately low level to assure vehicle safety. In the present study, the oxidation of diesel fuel containing 5% FAME is investigated. Several kinds of FAMEs were examined, including reagents such as methyl linoleate and methyl linolenate, as well as commercially available products. The level of acid, peroxide, water, and methanol and the pressure of the testing vessel were measured. The result shows that unsaturated FAMEs that have two or more double bonds are unstable. Also, water is generated by oxidation of FAME blended diesel fuel, accelerating corrosion of the terne sheet.
Technical Paper

Optimal Specifications for the Advanced Pedestrian Legform Impactor

This study addresses the virtual optimization of the technical specifications for a recently developed Advanced Pedestrian Legform Impactor (aPLI). The aPLI incorporates a number of enhancements for improved lower limb injury predictability with respect to its predecessor, the FlexPLI. It also incorporates an attached Simplified Upper Body Part (SUBP) that enables the impactor’s applicability to evaluate pedestrian’s lower limb injury risk also with high-bumper cars. The response surface methodology was applied to optimize both the aPLI’s lower limb and SUBP specifications, while imposing a total mass upper limit of 25 kg that complies with international standards for maximum weight lifting allowed for a single operator in the laboratory setting. All parameters were virtually optimized considering variable interaction, which proved critical to avoid misleading specifications.
Technical Paper

Lubricity of Liquefied Gas Assessment of Multi-Pressure/Temperature High-Frequency Reciprocating Rig (MPT-HFRR) -DME Fuel for Diesel

In this study, a MPT-HFRR (Multi-Pressure/Temperature High-Frequency Reciprocating Rig) was manufactured based on a diesel fuel lubricity test apparatus. The MPT-HFRR was designed to be used for conventional test methods as well as for liquefied gas fuel tests. Lubricity tests performed on a calibration standard sample under both atmospheric pressure and high pressure produced essentially constant values, so it was determined that this apparatus could be used for assessing the lubricity of fuel. Using this apparatus, the improvement of lubricity due to the addition of a DME (Dimethyl Ether) fuel additive was investigated. It was found that when 50ppm or more of a fatty acid lubricity improver was added, the wear scar diameter converged to 400μm or less, and a value close to the measured result for Diesel fuel was obtained. The lubricity obtained was considered to be generally satisfactory.
Technical Paper

Kinetic Measurements of HNCO Hydrolysis over SCR Catalyst

To meet the strict emission regulations for diesel engines, an advanced processing device such as a Urea-SCR (selective catalytic reduction) system is used to reduce NOx emissions. The Real Driving Emissions (RDE) test, which is implemented in the European Union, will expand the range of conditions under which the engine has to operate [1], which will lead to the construction of a Urea-SCR system capable of reducing NOx emissions at lower and higher temperature conditions, and at higher space velocity conditions than existing systems. Simulations are useful in improving the performance of the urea-SCR system. However, it is necessary to construct a reliable NOx reduction model to use for system design, which covers the expanded engine operation conditions. In the urea-SCR system, the mechanism of ammonia (NH3) formation from injected aqueous urea solution is not clear. Thus, it is important to clarify this mechanism to improve the NOx reduction model.
Technical Paper

Japanese Standards for Diesel Fuel Containing 5% FAME: Investigation of Acid Generation in FAME Blended Diesel Fuels and Its Impact on Corrosion

The Agency of Natural Resources and Energy, Ministry of Economy, Trade and Industry has conducted conformity tests of diesel fuel containing Fatty Acid Methyl Ester (FAME) to amend diesel fuel standards in Japan. The objective of the tests is to examine appropriate specifications of diesel fuel containing FAME for automotive use for existing vehicles in the Japanese market. The conformity testing includes verification of fuel system component compatibility, tail pipe emissions, and characterization of the reliability and durability of the engine system, including the fuel injection system. In designing the conformity tests, the maximum FAME concentration was 5%. Most of the new standards are essentially equivalent to EN14214, but the total acid number (TAN) of specific acids, and oxidation stability of the new standards for diesel fuel containing FAME, are different from EN14214.
Technical Paper

JCAPII Cross Check Tests of Fast Electrical Mobility Spectrometers for Evaluation of Accuracy

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.
Technical Paper

Influence of Ferrocene on Engine and Vehicle Performance

Ferrocene is used as an antiknock additive to replace lead alkyls. To clarify the influence of one metal additive, ferrocene, on engine, following experiments were carried out. The insulation resistance of spark plugs was measured, deposits in the engine were analyzed, and an exhaust emission and fuel economy tests were conducted using gasoline containing ferrocene. The deposit, which contained iron oxides, adhered to the combustion chamber, spark plugs, and exhaust pipe when the engine operated with gasoline containing ferrocene. When vehicles operated with gasoline containing ferrocene, fuel consumption increased and the exhaust temperature rose. In addition, an abnormal electrical discharge pattern was observed in spark plugs operating at high temperatures. Iron-oxide of Fe3O4 is changed into Fe2O3 under high temperatures. Discharge current flows in iron oxides including Fe2O3 because the conductivity of Fe2O3 increases at high temperatures.
Technical Paper

Ignition Process of Intermittent Short-Circuit on Modeled Automobile Wires

Our study was conducted to demonstrate the primary factors involved in fires which result from an automobile's electrical wire harness system with fuses. In our experiments we used modeled automobile wire harnesses to study the processes of ignition and the resultant fires. Current was passed through blade type fuses to a portion of the harness and was intermittently short-circuited by a grounded metal plate. The nominal current ratings of the fuses we used were lower than or equal to 30 amperes [A], and the operating current was 30A at 12 Volts. Current flowed to the harness specimens through a DC power source. We found that electrical tracking with scintillation, caused by a weak electric flow through carbonized wire insulation, rarely generated flames in the wire harnesses without blowing the fuse. Ignition was never observed on the insulation near the areas shorted by the arc and/or overloaded currents going to the wire elements.
Technical Paper

Feasibility Study of Urea SCR Systems on Heavy Duty Commercial Vehicles

Four urea SCR systems were developed and evaluated on a C/D and on the road to investigate their potential for Japanese emission regulations in 2005 and beyond. Test results showed that NOx conversion ratios were 50 to 70% during the Japanese D13 mode cycle, and the ratios under the transient driving cycle were lower than those tested during a steady state. Unregulated emissions, such as benzene, aldehyde and benzo[a]pyrene, existed either at a trace level using the oxidation catalyst, or lower than a base diesel engine, when no oxidation catalyst was used. The health effects of particulate matter emitted from the SCR system were almost the same as those from conventional diesel engines, as evaluated by the Ames test and in vitro micronucleus test. Thermal degradation products, such as cyanuric acid and melamine, were two to four figures lower compared with the toxicological information of Safety Information Resources Inc. (SIRI).
Technical Paper

Energy Absorption Properties of FRP tube under Commission Load

Tapered FRP tubes have high-energy absorption performance under axial compressive load. FRP will be useful for structural material of a shock absorber in the various industries. And in order to simulate the behavior of this material, several experimental tests and numerical simulations using FEM have been carried out recently. However, it is still difficult to simulate the behavior of tapered FRP tubes involving so called “Progressive Crushing” with FEM properly, because the fracture mechanism contains various kinds of fractures such as delamination, fiber fracture and so on. In this study, we proposed a specially designed FEM model based that is useful for the crush-worthiness analysis of FRP tube.
Technical Paper

Effect of Alcohol Fuels on Fuel-Line Materials of Gasoline Vehicles

In 1999, some Japanese fuel suppliers sold highly concentrated alcohol fuels, which are mixtures of gasoline and oxygenates, such as alcohol or ether, in amounts of 50% or more. In August 2001, it was reported that some vehicle models using the highly concentrated alcohol fuels encountered fuel leakage and vehicle fires due to corrosion of the aluminum used for the fuel-system parts. The Ministry of Economy, Trade and Industry (METI) and the Ministry of Land, Infrastructure and Transport Government of Japan (MLIT) jointly established the committee on safety for highly concentrated alcohol fuels in September 2001. The committee consisted of automotive technology and metal corrosion experts knowledgeable about preventing such accidents and ensuring user safety. Immersion tests were conducted on metals and other materials used for the fuel-supply system parts to determine the corrosion resistance to each alcohol component contained in the highly concentrated alcohol fuels.
Technical Paper

Development of an FE Flexible Pedestrian Leg-form Impactor (Flex-PLI 2003R) Model and Evaluation of its Biofidelity

A biofidelic flexible pedestrian leg-form impactor, called Flex-PLI, was developed by the Japan Automobile Manufactures Association, Inc. (JAMA) and the Japan Automobile Research Institute (JARI). Its latest version is called Flex-PLI 2003. The Flex-PLI 2003 responses have been validated at the component level (thigh, leg, and knee independently) but not at the assembly level (thigh-knee-leg complex). Furthermore, there was no FE Flex-PLI model. This research developed a FE Flex-PLI 2003R model (Flex-PLI 2003R means that the thigh and leg mass of Flex-PLI 2003 is adjusted to AM 50). The FE Flex-PLI 2003R model biofidelity has been evaluated at both the component level and the assembly level, where it demonstrated high biofidelity.
Technical Paper

Development of a Biofidelic Flexible Pedestrian Leg-form Impactor (Flex-PLI 2004) and Evaluation of its Biofidelity at the Component Level and at the Assembly Level

JAMA-JARI has developed a biofidelic flexible pedestrian leg-form impactor (Flex-PLI 2004) by making several modifications to the Flex-PLI 2003 to improve usability, durability and biofidelity. Biofidelity evaluation for the Flex-PLI 2004 was estimated at the component level (thigh, knee, and leg individually) as well as at the assembly level (thigh-knee-leg complex), using an objective impactor biofidelity evaluation system based on a method developed by Rhule et al. to eliminate any subjective prejudice in an impactor biofidelity evaluation. Applying the biofidelity evaluation system to the Flex-PLI 2004, the average impactor biofidelity rank (IBR) score became 1.22 at the component level and 1.26 at the assembly level. These IBR scores mean that the Flex-PLI 2004 has good biofidelity at the component level as well as at the assembly level.
Technical Paper

Data Processing Method of Finger Blood Pulse for Estimating Human Internal States

It was found that the finger blood pulse shows various fluctuations in different driving conditions. The nature of the finger blood pulse fluctuations was used for estimating a driver's internal state. Indexes suitable for expressing the fluctuations were moment and density; these indexes were calculated by using a return-map. However these results were measured by an off-line system and were calculated after the experiment. So, an on-line (real-time) system was needed in order to construct a driver's internal state monitoring system. As a first step, an online system for estimating the human internal state was developed. This system is available for estimating the human internal state every 30 seconds.