Three dimensional numerical analysis of engine compartment flow

Abstracts result, increasing sulfur content of gasoline significantly raised exhaust CO, THC and NOx emissions from the vehicle equipped with a fresh catalyst or an aged catalyst. The sulfur affected performance of catalyst, and influenced paraffins conversion more than olefins and aromatics conversions. The sulfur effect on benzene conversion was greatest in aromatics. Investigation of the Relation between Fuel Components 9535224 and Exhaust HC Emissions (I) Toshiaki Tanaka, Yasunori Takei, Toshifumi Takaoka (Toyota Motor Corporation), Shuichi Kubo (Toyota Central R&D Labs., Inc.) Satoshi lguchi, Masahiko Nakada (Toyota Motor Corporation) The effects of gasoline fuel HC components on individual exhaust HC emissions have been investigated. It is found that aromatics are easily emitted into exhaust gases. Consequently total HC emissions increase as aromatic components increase. Particularly, heavy aromatics (i.e. C8 - 1 are highly emitted into exhaust gases. It seems that heavy aromatics tend to be absorbed into the oil films on the cylinder wall and desorbed during expansion stroke compared to other fuel components including light aromatics (C6, C7). On the other hand, increase of light paraffins and olefins shows decrease of total HC emissions. 9535233 Effects of Diesel Fuel Composition on Exhaust Emissions from DI Diesel Engine - Study of The Use of Light Cycle Oil as A Component of Diesel Fuel Masataka Morinaga, Haruhisa Yoshida, Haruo Takizawa, Shigehisa Yamada, Yasuo Iwamiya (COSMO Research Institute) An emission test was performed in a DI diesel engine to evaluate the use of light cycle oil (LCO) as a component of diesel fuel. Most test fuels contained a kind of some LCOs which had varied ranges of the distillation and their performances compared with that of conventional diesel fuel. In this test, although the total aromatic hydrocarbons had no effect on particulate emissions, the poly-aromatic hydrocarbons significantly affected on SOF in the emissions. Furthermore, to keep the cetane number, the gaseous emissions became same level on any fuels. 9535242 A Study on Combustion and Emission Characteristics of Natural Gas Engines. Toru Sekiba, Yasunari Hanaki, Mitsunori Ishii, Eiji Inada, Akihide Okada, Shizuo Ishizawa (Nissan Motor Co. Ltd.,) In this study of the conversion characteristics of three-way catalysts, it was found that the conversion efficiency of total hydrocarbons was much lower in the lean-mixture region. The reduced efficiency was traced to lower conversion and poor reactivity of low-end hydrocarbons and to a higher concentration of H20. In addition, the ratio of methane in the exhausted THC was virtually identical to its ratio in the fuel. This indicates that the ratio of each component of exhaust THC can be estimated from its constituent ratio in the fuel. 9535251 Fuel Property Detection Using Fuel Density Susumu Sakagami, Manabu Iwasaki, Masahiko Shimamura (Unisiajecs) By recent improvement in lean-burn technology and catalyzer, vehicle emission at driving has been decreased. At engine start, however, the emission is increased because the oxygen-sensor and the catalyzer are not in an activated state and also because the fuel control for certain engine control at engine start supplies needless fuel. The fuel amount injected according to the control can be minimized to decrease emission, if the fuel property is sensed before engine start. As fuel property is correlated with fuel density, we have developed a fuel density detecting sensor. This report describes its structure and the results of experiments. A Mechanism for the Needle Crystal Formation from 9535260 Magnesium Detergents in Engine Oils Noriyuki Naganuma, Gen Ogino (Japan Energy Corp.), Takashi Kikuchi, Kenyu Akiyama (Toyota Motor Corp.1 Engine oils are always formulated with overbased metallic detergents to neutralize acid, and to prevent the deposition of degraded products.

319 Among the detergents, overabased magnesium detergents sometimes form the needle crystals. From the research on mechanism of the needle crystal formation, we found the great effect of water content and carbonic acid gas content in an oil, and the type of the magnesium detergents. Gasoline Engine Oil Durability on Fuel Economy Improve9535279 ment Performance Kenyu Akiyama, Takashi Kikuchi, Shinichi Sugiyama, Tsuyoshi Ashida, Isao Tanaka (Toyota Motor Corporation) Fuel economy improvement of engine oil can be achieved by lowering oil viscosity and formulating friction modifiers. This improvement is measured with ASTM Seq. VI test under a short mileage accumulation condition. However, the accumulation in Seq. VI may be too short to know oil durability on fuel economy improvement up to oil drain in cars. The improvement may be lowered in cars. Authors studied the fuel economy durability with vehicle tests measuring viscosity and friction coefficient changes of used oils and determining the amount of friction modifier (MoDTC) remained in used oils. 9535288 Study of The Effect of Viscosity Index Improver on Engine Friction Hirohiko Ohtsu, Koichi Kubo (Showa Shell Sekiyu), Kenyu Akiyama, Tsuyoshi Ashida (Toyota Motor Corp.) The effect of viscosity index improver on engine friction torque were studied using a motored engine friction rig. In addition, the friction reduction of the test oil was assessed in comparison with an ASTM reference oil, HR (SAE2OW-30), under various engine reduction resulting from change in the type of viscosity index improver was estimated. A predictions of torque reduction based on the viscometrics of different molecular weight DPMA viscosity index improvers was established. 9535297 Effect of Lubricating Oils on Flaking of a Wet Clutch Tohm Matsuoka, Noboru Fujiwara, Akihiro Ohashi, Takeo Nakayama (Mitsubishi Oil Co., Ltd.) As a study of the flaking mechanism of a wet clutch composed of paper-based facings, the flaking mechanism is classified into two types. One is carbonization of facings by friction heating, the other is cleavage of cellulose fiber by pressure. And further, the effect of additives against facings was investigated on a simple simulation test, in which an additive was found to inhibit degradation of cellulose fiber. It enabled to maintain the strength of cellulose fiber. Consequently a wet clutch has become longer-lived. 9535305 A Study on Transient Performance of Supercharged Engine - Analysis of Primary Factors Affecting Transient Charging Effkiency Yasuhide Yano, Tadashi Nakagawa, Masanobu Kotoku (Mazda Motor Corporation) A one-dimensional numerical analysis program has been developed in order to study the transient performance of supercharged engine. Studying theoretically, the factors affecting charging efficiency were initially narrowed down to the volumetric efficiency and the volume of intake system. Their influence to the rate of increase of charging efficiency was made clear using the program. Conditions that the engine specification must be satisfied from the viewpoint of transient performance were also established. 9535314 Three Dimensional Numerical Analysis of Engine Compartment Flow Shizuo Abe, Makoto Suzuki (Toyota Motor Corporation) Three dimensional numerical simulation was employed for analyses of engine compartment flow. Analytical mesh was generated by a new method applying STAR-CD. This method make it possible to accurately define the object shape easier than conventional multi-block method. Fan model was developed by measuring the axial and rotational component of flow velocity behind fan blades. As the results, it was found that fan rotation has large effect on the engine compartment flow especially ,under low vehicle speed condition, and reversing the fan rotational direction significantly charges the flow pattern and ambient temperature in engine compartment.