著者

篠木 俊雄 前田 毅 舟木 治郎 平田 勝哉

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:18848346)

巻号頁・発行日

vol.78, no.787, pp.415-419, 2012 (Released:2012-03-25)

参考文献数

8

被引用文献数

3 3

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Supposing the design of ethanol steam-reforming reactors, the authors conduct experiments for Cu/ZnO/Al2O3 catalyst. Using a household-use-scale reactor with well-controlled temperature distributions, the authors compare experimental results with chemical-equilibrium theories. It has revealed by Shinoki et al. (2011) that Cu/ZnO/Al2O3 catalyst shows rather high performance with high hydrogen concentration CH2 at low values of reaction temperature TR. So, in the present study, the authors reveal the influences of liquid-hourly space velocity LHSV upon concentrations such as CH2, CCO2, CCO and CCH4 and the influence of LHSV upon the ethanol conversion XC2H5OH, in a range of LHSV from 0.05 h-1 to 0.8 h-1, at S/C = 3.0 and TR = 520 K. And, the authors reveal the influences of the thermal profile upon CH2, CCO2, CCO, CCH4 and XC2H5OH, for several LHSV's. To conclude, with well-controlled temperatures, the reformed gas can be close to the theory.

著者

高田 稜一 高橋 江梨香 内田 孝紀 杉谷 賢一郎 谷川 博哉 野口 尚史 平田 勝哉

出版者

一般社団法人 日本機械学会

雑誌

流体工学部門講演会講演論文集 (ISSN:24242896)

巻号頁・発行日

pp.OS03-05, 2020 (Released:2021-05-25)

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In the present study we investigate the relationship between various aerodynamic characteristics and attack angle α for FP (a flat plate), NACA0015 and iNACA0015 (the NACA0015 placed back to front) by numerical analysis and water-tank experiment at Re = 100 – 800. Then, we reveal the effects of α upon various aerodynamic characteristics such as the lift coefficient CL, drag coefficient CD and the lift-to-drag ratio CL/CD. In order to discuss these revealed α effects, we further visualize the flow around the airfoils in terms of the velocity vector, vorticity and the Q value at α = 0 – 30 deg., based on PIV analyses by water-tank experiment. Such results suggest that FP is similar not with NACA0015 but with iNACA0015 from an aerodynamic point of view.

著者

平田 勝哉 川北 正寿 飯島 高善 古賀 光泰 紀平 光彦 舟木 治郎

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:18848346)

巻号頁・発行日

vol.77, no.776, pp.1111-1126, 2011 (Released:2011-04-25)

参考文献数

12

被引用文献数

1

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The aerodynamic characteristics of airfoils have been researched in higher Reynolds-number ranges more than 106, in a historic context closely related with the developments of airplanes and fluid machineries in the last century. However, our knowledge is not enough at low and middle Reynolds-number ranges. So, in the present study, we investigate such basic airfoils as a NACA0015, a flat plate and the flat plates with modified fore-face and after-face geometries at Reynolds number Re < 1.0×105, using two- and three-dimensional computations together with wind-tunnel and water-tank experiments. As a result, we have revealed the effect of the Reynolds number Re upon the minimum drag coefficient CDmin. Besides, we have shown the effects of attack angle α upon various aerodynamic characteristics such as the lift coefficient CL, the drag coefficient CD and the lift-to-drag ratio CL/CD at Re = 1.0×102, discussing those effects on the basis of both near-flow-field information and surface-pressure profiles. Such results suggest the importance of sharp leading edges, which implies the possibility of an inversed NACA0015. Furthermore, concerning the flat-plate airfoil, we investigate the influences of fore-face and after-face geometries upon such effects.

著者

平田 勝哉 中森 真志 谷川 和哉 片岡 福太郎 藤本 泰貴 篠木 俊雄 谷川 博哉 舟木 治郎

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:18848346)

巻号頁・発行日

vol.79, no.808, pp.2873-2884, 2013 (Released:2013-12-25)

参考文献数

15

被引用文献数

2 2

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The authors develop a small and simple steam-reforming reactor in a home-use size for n-dodecane as a heavy-hydrocarbons fuel. Under such a well-controlled condition by a thermal diffuser as the reactor satisfies two target-temperature criteria, the authors measure the inside-temperature profile and the hydrogen molar fraction (concentration) CH2, together with the molar fractions CCH4, CCO and CCO2 of other main gas components such as CH4, CO and CO2, respectively, using a gas chromatograph. In addition, the authors conduct theoretical calculations based on the thermal-equilibrium theory, and reveal CH2, CCH4, CCO and CCO2, as well as experiments. As a result, the authors successfully achieve suitable inside-temperature profiles. The steam-reforming reaction becomes more active at the position where temperature T > 800 K. The effects of the steam-to-carbon molar ratio S/C upon CH2, CCH4, CCO and CCO2 are shown, experimentally and theoretically. The experimental results agree well with the theoretical ones. Besides, carbon balance and conversion ratio show high accuracy in experiments.

著者

平田 勝哉 渕 拓也 大西 祐介 多久島 朗 佐藤 誠司 舟木 治郎

出版者

同志社大学

雑誌

同志社大学理工学研究報告 (ISSN:00368172)

巻号頁・発行日

vol.51, no.1, pp.1-8, 2010-04

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本論分は,任意回転軸を持った三次元ファンの翼表面上の微小な非定常圧力の測定技術を確立するための基礎研究である.作動流体は空気であり,任意の姿勢で回転する圧力センサは,二重のシュラウドシステムによりしっかり密封する.その任意の姿勢による回転運動は,圧力センサを片持支持部材に埋め込むことによって作られ,それは回転円盤につながれている.結論として,我々は,圧力センサからの信号の無効成分である遠心力効果や重力効果が,主要な支配的である影響であると定量的に決めた.This paper concerns a fundamental approach to develop the measuring technology for minute fluctuating pressures on the three-dimensional blade surfaces of the fan which rotates with an arbitrary rotation-axis direction. Using air as working fluid, a pressure transducer rotating with an arbitrary attitude is closely sealed by a twofold shroud system. The rotational motion with an arbitrary attitude is produced by fixing the pressure transducer to the cantilever which is connected to a motor-driven disc. To conclude, we have quantitatively determined governing effects upon the non-effective component of the pressure-transducer signal, which are the centrifugal-force and the gravitational-force effects.

著者

舟木 治郎 渕 拓也 大西 祐介 長坂 繁弥 多久島 朗 佐藤 誠司 平田 勝哉

出版者

The Japan Society of Mechanical Engineers

雑誌

日本機械学会論文集 C編 (ISSN:03875024)

巻号頁・発行日

vol.77, no.779, pp.2795-2804, 2011

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The present study is a fundamental approach to reveal the minute fluctuating pressures on three-dimensional blade surfaces of a basic propeller fan. Because, among the concerning physical quantities, the unsteady pressures on the rotating blades give us useful information for the fan flow and its sound-noise level. The authors correct the centrifugal-force effect, the gravitational-force effect and the other leading-error effects for accurate measurements of the minute pressures using a measuring technology developed by the authors (Hirata et al., 2009). As a result, we show the Reynolds-number effects and the spatial distributions on the blade of both time-mean pressure and pressure-fluctuation intensity.

著者

平田 勝哉 清水 康介 福原 憲典 山内 一樹 川口 大輔 舟木 治郎

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.75, no.749, pp.28-39, 2009-01-25

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In this study, we deal with the tumbling, which is rotating motion with the axis perpendicular to the falling direction. Our purpose is to reveal the fundamental aerodynamic characteristics of the tumbling, experimentally. Regarding a test plate, we consider a prism with a rectangular cross section with a depth-to-width ratio λ of 0.3. The results are as follows. The reduced terminal rotating rate Ω^*, the lift coefficient C_L, the drag coefficient C_D and the lift-to-drag ratio C_L/C_D are independent of the aspect ratio AR, when AR is greater than 10. As the inertia momen ratio I^* increases from zero to 50, Ω^*, C_L and C_D increase. However, Ω^*, C_L and C_D become almost constant, at I^* greater than 50. We propose the empirical formulae to predict them. At low I^*, the tumbling shows a dominant periodicity of 360deg.