セミナー発足に際してのごあいさつ(1997.4)


第 224 回 Q-NA セミナー
日     時2008 年 10月 21日 (火) 15:30 - 17:00
場     所九州大学箱崎キャンパス 理学部 3号館 3階 3311 号室
講 演 者M.F. El-Amin (九大工学研究院/South Valley University)
共 著 者金山 寛 (九州大学工学研究院)
題     目Integral solutions for some turbulent quantities of small-scale hydrogen leakage: non-buoyant and buoyant jets
概     要Throughout this presentation some physical turbulent properties of the non-buoyant (momentum-dominated) jet buoyant jet (plume) of small-scale hydrogen leakage are obtained. The integral method was used to derive the cross-stream velocity, Reynolds stress, the dominant turbulent kinetic energy production term, turbulent eddy viscosity and turbulent eddy diffusivity. Also, both the turbulent Schmidt number and the correlation of the normalized jet-feed material density and the normalized momentum flux density are estimated. The experimental results for the turbulent buoyant hydrogen-air jet given by Schefer et al. and other literature are used to be inserted in the integral method. Some empirical Gaussian expressions for the mean streamwise velocity and concentration with their associated coefficients of the turbulent buoyant hydrogen-air jet are integrated with the governing equations to obtain the unknown turbulent terms. It is well known form literature that the centerline velocity is proportional with (for non-buoyant jet and for buoyant jet) while the centerline concentration is proportional with (for non-buoyant jet and for buoyant jet). The hydrogen-air buoyant jet is comparable with other variable density jets such as helium-air jet as an example of the buoyant jets, while, the momentum-dominated regime or non-buoyant hydrogen-air jet is compared with the air-air jet as an example of non-buoyant jets.
Keywords: Hydrogen leakage; buoyant jet; non-buoyant jet; turbulent Schmidt number; integral method.

世話人
田上 大助 (九州大学 マス・フォア・インダストリ研究所)
渡部 善隆 (九州大学 情報基盤研究開発センター)

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