著者

福田 基一

出版者

環境技術学会

雑誌

環境技術 (ISSN:03889459)

巻号頁・発行日

vol.2, no.10, pp.717-722, 1973-10-18 (Released:2010-03-18)

著者

小林 啓二 小嶋 直哉 福田 基一

出版者

山口大学工学部

雑誌

山口大学工学部研究報告 (ISSN:03727661)

巻号頁・発行日

vol.34, no.2, pp.p225-231, 1984-03

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An anechoic room for engine noise test was constructed. In constructing it, the sound absorbing wall with its supporting structures was carefully designed because their strong influence on the performance of the anechoic room. The back ground noise, the inverse square law and the mean absorption coefficient of this room were examined in detail. From these experimental results, it was confirmed that this anechoic room showed the sufficient characteristics for the experimental researches on noise generation from running engines.

著者

福田 基一 和泉 晴夫

出版者

山口大学

雑誌

山口大学工学部研究報告 (ISSN:03727661)

巻号頁・発行日

vol.16, no.1, pp.71-76, 1965-11

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To examine the effects of length of an exhaust pipe and engine speed in a small four-stroke cycle engine, the authors have measured the output of the engine and analysed some pressure diagrams for the exhaust pipe. Some conclusions obtained in such experiments are summarized as follow : 1) The maximum output occurs on account of the innertia effect of the exhaust system. 2) The maching conditions are expressed approximately by the following equation Q=cθ/12kNl where c : mean sonic velocity in exhaust system θ : period of exhaust port opening k : maching factor N : engine speed, r.p.m.l : length of exhaust pipe+correction value of open end. The maximum output occurs in case of Q≒1.