Showing papers in "Jsae Review in 1981"

Study of the methanol-reformed gas engine

Abstract: Methanol reacts in the presence of a catalyst and decomposes into a gas made up of hydrogen, carbon monoxide, etc. This is an endothermic reaction, hence the calorific value of the fuel increases. An experiment was conducted on the characteristics of an Otto cycle engine using reformed gas and methanol as fuels. As a result, it was confirmed that the engine provided high thermal efficiency and clean exhaust characteristics at a compression ratio of 14.0 and an excess air ratio of 1.7.

State of the art and future trend of hydrogen-fueled engines

Abstract: The article compares hydrogen with liquefied natural gas (lng), or methane, and also alcohols as alternative engine fuels. Although it is shown that hydrogen is a promising fuel for the future, a difficult problem is that of storage with metal hydride and liquid hydrogen tanks considered to be the most feasible. The advantages of these methods are considered in detail. The author discusses the basic properties of hydrogen as an automobile fuel and also examples of hydrogen-fueled cars. (TRRL)

Electro-pneumatically operated proportional clutch for semi-automatic power transmission

Abstract: The design concept of this semi-automatic power transmission is to provide a conventional mechanical transmission with a simple clutch servomechanism. For this purpose, we have developed a new type of electro-pneumatically operated proportional mechanism which controls the clutch pedal position in proportion to the electronic signal of engine revolution and carries out the vehicle starting procedure automatically. In this paper, we show the test results of the clutch control mechanism applied to a passenger car mechanical transmission and examine the vehicle starting characteristics theoretically.(a) (TRRL)

Ignitability of hydrogen-air mixture by hot surfaces and hot gases in hydrogen-fueled engines

Abstract: It is necessary to confirm the ignitability of hydrogen in terms of abnormal combustion of hydrogen-fueled engines and safe handling of hydrogen. In this regard, the authors have carried out experiments on the effects of the heating methods, the kinds of metal particulates and metal oxide grains on the ignitability of hydrogen-air mixture by means of model equipment, in which the mixture flowed into a constant volume combustion chamber and contacted a hot metal surface or hot gas flow, and obtained some useful results on the ignition characteristics of hydrogen-air mixture.(a) (TRRL)

Swirl production in four-stroke engine cylinder--analysis in motoring operation

Abstract: A new method for predicting the swirl speed in an engine cylinder has been presented The air jet issuing from the inlet valve is presumed to contribute to swirl production after impinging upon the cylinder wall and piston top surface By applying also a velocity profile of turbulent plane wall-jet, it is possible to predict approximately the swirl speed and its velocity profile in an engine cylinder

Design concept of front suspension compliance application to the Bluebird 910 with examination of steering shimmy

Abstract: It is known that the concept of suspension compliance is one of the important parameters in achieving better handling performance and improved riding comfort. Theoretical and experimental analyses were carried out on the influence of the front suspension compliance on steering shimmy and riding comfort. The results of the study were applied to the front suspension design of the Bluebird 910.

Present and future of countermeasures for noise and vibration problems of small passenger cars

Abstract: Since the small passenger car standard was revised in January 1976 by Japanese law, new models have been introduced to the market and small passenger cars have regained their popularity. To reduce their vibration and noise, thus enabling them to run quietly and free of vibration as befitting small-sized popular cars, efforts have been expended to lower engine rpm, reduce the vibration of the driving system, and improve the engine mountings. As a result, the noise level has been drastically lowered as compared with the earlier small passenger car models. The future problem is to develop a new technology based on A fresh concept to deal with the technical difficulties of meeting the social needs for conservation of resources and energy, and the anticipated stricter control on external vehicular noise and exhaust gas emission while achieving A further reduction of vibration and noise. The most important themes to be dealt with in the future will be the selection of an optimum driving system, the simultaneous reduction of weight and noise, and the development of an efficient means of sound insulation. (TRRL)

Inlet dynamic pressure and volumetric efficiency of four cylinder fuel injected engine with air-surge-tank

Abstract: Volumetric efficiency and inlet pressure vibration of a four cylinder engine with air-surge-tank was investigated. It was found that the inlet pressure vibration in the induction system consists of two main waves, which can be distinguished clearly and explained by acoustic theory. One has a short period which is determined by factors of the induction system from the air purge-tank to the intake valve, the other has a relatively long period which is determined by overall design factors of the induction system. According to the numerical calculation, it was clarified that the volumetric efficiency is strongly influenced by the pressure in the short period before the intake valve closed. Therefore, how the design factors of the induction system are affecting the volumetric efficiency of the four cylinder engine with air-surge-tank can be shown by the following procedure. First, the mean pressure of two main waves in the short period before the intake valve closed are examined. It the pressure is positive value, the volumetric efficiency is improved by the wave. Second, the relation between the design factors and these waves is calculated by using acoustic theory.

Study on spark discharge current for noise suppression

Abstract: The ignition system of any internal combustion engine is well known as a major source of radio frequency interference, and various kinds of suppressors are adopted in order to reduce ignition interference. However, most of them are intended to decrease the spark discharge current by means of inserting resistors in the ignition circuit. Of primary importance for noise suppression is the capacitive component of ths circuit which can decrease current amplitude. In this paper the authors present for noise suppression. In this paper the authors present a theory on the capacitive current in the ignition cable, and compare it with experimental results. As a result, they have confirmed that the agreement between the theory and experiments was satisfactory to some degree and the noise current can be roughly determined from the theoretical equation. Based on these results, it is possible to collect the noise current at a part of the cable by applying the wire-wound resistor cable, and thus achieve more effective noise suppression.

Improvement of combustion in spark ignition engine with yics

Abstract: This report concerns the introduction of the Yamaha Induction Control System (YICS), which promotes rapid combustion of fuel in spark ignition engines by forcing a swirling motion in the cylinder charge. This increases the combustion rate and reduces fuel consumption. (Author/TRRL)

Relation between gas flow pattern and heat flux on piston crown surface

Abstract: The relation between gas flow and heat flux on the piston crown surface of the pre-combustion type diesel engine was investigated. The gas flow, the collision position of the jet and the direction of flow from the orifice of the precombustion chamber on the piston crown surface were observed by means of the oil film method. At the same time, the heat flux into the piston surface from the gas was measured. From the above-mentioned result, the relation between gas flow and heat flux was deduced. As a result, it was shown that heat flux (mean and maximum during one cycle) is affected by gas flow and gas temperature which are affected by equivalence ratio (Phi). Qualitatively, the farther it recedes from the collision area of the jet, the less the heat flux grows.

Sintered alloy materials for valve seats

Abstract: Sintered materials for automotive valve seats have recently come to be used also for diesel engines. The sintered materials now in use for valve seats were classified into several categories, and some examples of applications of composite valve seats using sintered materials that are expected to further increase in the future from the standpoint of energy saving are introduced. In addition, the views on troubles peculiar to valve seats when leaded gasoline is used as well as on the countermeasures for preventing them are presented.