著者
永井 厚司 岡部 俊彦 キム ギョンミン 吉橋 照夫 小原 哲郎 大八木 重治
出版者
一般社団法人 日本燃焼学会
雑誌
日本燃焼学会誌 = Journal of the Combustion Society of Japan (ISSN:13471864)
巻号頁・発行日
vol.52, no.159, pp.86-93, 2010-02-15
参考文献数
27

<p>Pulse detonation engines (PDEs) are expected to be the next-generation engine systems, and are expected to have applications in various fields. One of the fundamental problems faced during the development of PDEs is the deflagration to detonation transition (DDT). In order to realize a PDE, it is essential to shorten a parameter of detonation transition called a detonation induction distance (DID). However, the mechanism underlying the DDT process and methods to shorten DID in narrow channels have not yet been understood. An experimental study on DDT process in a narrow rectangular channel with a height of 1-5 mm and a width of 8 mm was carried out by employing pressure transducers, ionization probes, and sooted plate technique in oxyhydrogen mixtures. The effects of the tube height and equivalence ratio on pressure detonation limits were discussed. Detonation velocity, DDT process, and DID were discussed on the basis of pressure history and soot track record. Overdriven detonation and attenuated detonation were observed in the narrow channel. The DID value measured on the basis of the soot track record in the present study was in the range of the empirical formula obtained by the other researchers.</p>
著者
三上 真人 大八木 大史 小嶋 直哉 菊池 政雄 若嶋 勇一郎 依田 真一
出版者
一般社団法人 日本燃焼学会
雑誌
日本燃焼学会誌 = Journal of the Combustion Society of Japan (ISSN:13471864)
巻号頁・発行日
vol.45, no.134, pp.238-247, 2003-11-30
参考文献数
30
被引用文献数
3

<p>A new concept of the droplet array generation technique was proposed to realize a high quality and high reliability performance of microgravity experiments of multiple-droplet combustion. Each fuel droplet was formed on the intersection of the X-shape fine SiC fibers by supplying the liquid fuel through a fine glass tube. Several sets of the X-shape fibers and corresponding fine glass tubes were aligned at an interval to make a droplet array. All the droplets in array were simultaneously generated in a short time. In flame spread experiments, an end-droplet was ignited by a hot-wire igniter to initiate the flame spread along the array. Microgravity experiments of droplet array combustion were demonstrated with the new droplet array generation technique using a drop experiment facility MGLAB in Japan. In microgravity, large droplets, which were often failed to be generated in normal gravity, were successfully generated through this method. The present technique is also effective in droplet array combustion experiments using a high-volatility fuel, whose prevaporization is not negligible. The flame spread rate and the flame spread limit of linear droplet arrays were compared with existing experimental results. Effects of the suspending fiber on the flame spread were also discussed.</p>