著者

永井 秀和 趙 黛青 山下 博史

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.71, no.709, pp.2339-2345, 2005-09-25

被引用文献数

3

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In order to clarify the effects of density ratio and laminar burning velocity on the vortex bursting phenomenon, the premixed flame propagation in swirling flow has been examined by the numerical calculation for various preheating temperatures and equivalence ratios. In this calculation, the flame is fixed in the computational domain by adding an axial flow to the unburnt premixed gas so as to obtain the steady state propagation characteristics. The obtained results are as follows: The present flame propagation velocities relatively agree on "the back-pressure drive flame propagation theory (radial expansion)" proposed by Ishizuka et al. The variation of the pressure along the vortex axis occurs between the inflow part and the flame front, and the pressure in the burnt region is almost uniform. Therefore, the propagation speed must be estimated by the Bernoulli's equation by using the density of unburnt mixture. We have proposed a new formula on the basis of the present calculation results, and have confirmed that flame propagation speed accords qualitatively and quantitatively with this formula. Moreover, we have suggested that, considering the application to the combustor with swirling flow, the preheating of premixed gas enhances its performance due to the large burning velocity.