著者

吉田 正武

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.64, no.617, pp.305-311, 1998-01-25 (Released:2008-03-28)

参考文献数

8

被引用文献数

1

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The author had previously reported that work done by a power stroke of 4-stroke gasoline engine is expressed as a function of engine factors (ignition timing, combustion period, heat release diagram and so on.) using an approximate pressure diagram of a cylinder, which is an approximate solution of the energy conservation equation. In this report, the author examined the effects of combustion period and heat release diagram on the work done by a power stroke. The results show that (1) the factors mentioned above have little effect on the thermal efficiency at the optimum ignition timing (MBT) ; (2) When combustion period is decreased, MBT shifts from advanced crank angle to retard crank angle in proportion to the decrease of combustion period ; and (3) The idea that a short combustion period improves thermal efficiency does not apply in the case of non-adiabatic engines.

著者

宋 載翼 吉田 正武 小栗 康文 五味 努

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.54, no.508, pp.3572-3578, 1988-12-25 (Released:2008-03-28)

参考文献数

13

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It has been reported in many papers that the humidity in a mixture causes a lower S. I. engine output because of the decrease of combustion heat and flame speed. However, the reason for and the extent of the above-mentioned effect have not yet been elucidated. In order to clarify the effect of humidity on S. I. engine output, the author applied the relationship between the humidity and combustion period to the analytical model of an S. I. engine which formulates the work done on a piston as a function of ignition timing. The result shows that (1) humidity decreases S. I. engine output by about 4.5% at constant spark advance, but at optimum spark advance the reduction is about 1.2%, and (2) the rate of flame speed reduction as a result of humidity in a engine is the same as the rate in burner.