著者
湯淺 朋久 阿部 豊 平野 覚
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 (ISSN:21879761)
巻号頁・発行日
vol.83, no.856, pp.17-00309-17-00309, 2017 (Released:2017-12-25)
参考文献数
17
被引用文献数
2

Toward the improvement of performance of the electric vehicle (EV), the design of the motor shape appropriate to heat removal is important. A typical EV motor is composed of a pair of coaxial cylinders with a fixed outer cylinder (stator) and a rotating inner cylinder (rotor). Some EV motors have axial slits on the stator wall. The present study numerically clarifies the physical mechanism of difference of Nusselt number between the case with slit and without slit. The heat transfer of the gap between the rotor and stator was obtained by the numerical calculation. A vortex structure observed by flow visualization experiment was reproduced in the numerical simulation, and velocity profiles showed good agreement with experimental data. The heat transfer rate for the case with slit in the high rotational speed was increased compared with that for the case without slit. Nusselt number was decomposed into the three terms which were the advection, turbulent transport and diffusion terms; the advection term of heat flux for the case with slit was increased compared with that for the case without slit because of the vortex structure. The Nusselt number on the slit surface was increased compared with that on the gap surface for the case with slit. It was implied that the difference of Nusselt number between the case with slit and without slit was caused by the presence of the vortex structure in the slit and the increase of heat flux for the case with slit.
著者
綿引 壮真 松本 聡 阿部 豊
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 (ISSN:21879761)
巻号頁・発行日
vol.83, no.852, pp.16-00476-16-00476, 2017 (Released:2017-08-25)
参考文献数
20

New viscosity measurement technique by using rotational breakup of electrostatically levitated droplet was developed. The new one-dimensional viscosity measurement equation is derived by integrating three-dimensional momentum equation based on the assumptions with axisymmetric shape and internal flow of levitated droplet. From the measurement result obtained, internal flow around the center of the dumbbell shape droplet is axisymmetric along the elongational axis. This result means that the present proposed new method is appropriate. In the present study, high accuracy image processing technique is applied to obtain the shape and curvature around the center of the dumbbell shape droplet by using the transformation to rotating coordinate system. The present technique can be applicable after the breakup start and before the shape of the droplet becomes asymmetric. This is reason why Euler force becomes so large that the symmetricity cannot be sustained. The newly proposed viscosity measurement technique makes it possible to estimate the viscosity within 10 % error in the range of the viscosity which the previous levitation technique cannot be available.
著者
山本 隆儀 渡部 俊三 阿部 豊
出版者
園藝學會
雑誌
園芸学会雑誌 (ISSN:00137626)
巻号頁・発行日
vol.50, no.3, pp.297-305, 1981
被引用文献数
1

ナシ樹, 特にセイヨウナシの水ストレスの激化の原因として, 過度の葉面蒸散ばかりでなく, 根の水吸収の能率の低さからもたらされる樹体水収支の不均衡が考えられるが, この面の調査はこれまで行われていない. 本実験では, 2年生のバートレット, レッド•バートレット及び二十世紀 (いずれもヤマナシ台) を用いて, ガラス室内で, 自動かん水器法, Impens らの着生葉の蒸散測定法及び heat pulse 法を組み合わせて, 樹体の水吸収速度及び蒸散速度の日変化ならびに季節的変化を測定し, 水収支及びこれらに及ぼす気象要因の影響などを調査した.<br>(1) 日吸水量と日蒸散量の値は共に, レッド•バートレット, バートレット, 二十世紀の順に大きく, 両者の比は3品種ともほとんど等しい変化を示した. 両者とも日平均<i>VPD</i>との間に, 気象要因の中で最も高い相関関係が見られ, 日平均<i>VPD</i>が約9mmHg, 総日射量が約400cal cm<sup>-2</sup>day<sup>-1</sup>を超えると, 日蒸散量が日吸水量を上回った. またそれら限界日平均<i>VPD</i>, 総日射量での日蒸散量 (=日吸水量) は, バートレットで約12g dm<sup>-2</sup>day<sup>-1</sup>, レッド•バートレットで約13.5g dm<sup>-2</sup>day<sup>-1</sup>及び二十世紀で約10.5gdm<sup>-2</sup>day<sup>-1</sup>であった.<br>(2) 5日間の日変化の調査では, いずれの日も朝から昼にかけて蒸散が吸水を上回り, 特に梅雨明けの晴天日にはその傾向が著しかった. 午後から夜を通して逆に吸水が蒸散を上回り, 午前に生じた水の不足分を補なっていた. 7月上旬や8月上旬に比べて, 8月下旬では. 昼間の蒸散速度に対して吸水速度が相対的により大きかった. このような傾向は3品種に共通して見られたものの, バートレットでは, 昼間の一時期に, 吸水と蒸散の両速度の較差がより広がることが見られた. 主幹部のheat pulse の移動速度の日変化曲線の形は, 上記両曲線の中間的な形を示したが, 若干ながら蒸散速度のそれに似ていた.<br>(3) 以上の結果, 蒸散と吸水との間に複雑な相互作用が認められたが, 昼間の水ストレスには, 本来的に根の水吸収能率が低く, 吸水が蒸散に追いつけないことが大きく関与するものと推察された. 更に, 実際のほ場栽植樹では, 根圏土壌の乾燥, 浅根化, 根腐れ及び根の生理的活性の低下などが併発することによって, 一層水ストレスが顕著になるであろう.
著者
斎藤 正徳 阿部 豊
出版者
公益社団法人 日本地震学会
雑誌
地震 第2輯 (ISSN:00371114)
巻号頁・発行日
vol.37, no.2, pp.237-245, 1984-06-25 (Released:2010-03-11)
参考文献数
8
被引用文献数
8 9

The viscous relaxation spectra and the marginal stability curves of Rayleigh-Bénard convection in a transversely isotropic fluid were computed. An incompressible, transversely isotropic fluid is expressed in terms of two material constants, L and δ. L is the viscosity pertinent to the shear in the horizontal plane and δ is the anisotrpy factor. δ is likely to be very large in the mantle if thin less viscous (molten) layers are aligned in the horizontal plane. At large δ the relaxation spectra become nearly constant over a wide range of wavenumber and its magnitude is determined essentially by the product L·δ. The flattness is consistent to the observed relaxation spectra. A similar effect is found in the Rayleigh-Bénard convection; the marginal stability curve flattens out to small wavenumber at large δ. This implies a possibility of thin convection cells in the earth's mantle.
著者
谷口 歩 今村 亮一 阿部 豊文 山中 和明 玉井 克人 新保 敬史
出版者
大阪大学
雑誌
基盤研究(C)
巻号頁・発行日
2022-04-01

腎不全は腎の線維化を中心とした不可逆な臓器不全である。間葉系幹細胞移植が腎に対して保護的に作用することが注目されているが、その臨床応用においては幹細胞移植に伴う取り扱いの煩雑さが問題である。我々は骨髄間葉系幹細胞を血中さらに障害部位に動員させる物質を特定し、これを利用した再生誘導医薬を開発した。化学合成された薬剤を静脈へ注射するのみで骨髄間葉系幹細胞を障害された腎臓に集められることが予測されるため、煩雑な幹細胞移植を伴わずに腎再生医療を臨床に応用できる可能性がある。本研究では腎障害動物モデルに対する再生誘導医薬の効果に関して、病理学的評価、分子生物学的評価および次世代シーケンス解析を行う。
著者
金子 暁子 野村 康通 高木 周 松本 洋一郎 阿部 豊
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.786, pp.207-217, 2012 (Released:2012-02-25)
参考文献数
14
被引用文献数
8 19

Microbubble has distinguished characteristics of large surface area to unit volume and small buoyancy. Recently microbubble generators with low energy and high performance are required to wide applications. In the present study, we propose one new effective technique to generate tiny bubbles with less than 200μm diameter utilizing a venturi tube under high void fraction condition. The objective of the present study is to elucidate the mechanism of bubble breakup phenomena in the venturi tube and to clarify the effects of parameters which are necessary to realize an optimum system experimentally. Under low velocity condition, bubbles which were observed with a high speed camera parted gradually in a wide region. On the contrary under high velocity condition, bubbles expanded after passing through the throat and shrank rapidly. Since the speed of sound in gas-liquid system is extremely lower than that of single-phase flow, the bubble breakup phenomenon in the venturi tube is explained as the supersonic flow in a Laval nozzle. With rapid pressure recovery in diverging area, expanding bubbles collapse violently. The tiny bubbles are generated due to the surface instability of shrinking bubbles.
著者
阿部 豊 青木 一義
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:03875016)
巻号頁・発行日
vol.71, no.712, pp.2864-2869, 2005-12-25 (Released:2011-03-03)
参考文献数
10
被引用文献数
3

It is expected to manufacture new materials under the micro-gravity environment in space. Under the micro-gravity environment, holding technology of molten metal is important to manufacture new materials. There are previous studies about droplet levitation by the acoustic wave for the holding technology. However it is still unknown experimentally and analytically how the acoustic wave act on the levitated droplet. In the present study, the technology to handle the material in space by the ultrasonic wave is developed and the simulation technique to evaluate the acoustic wave field and the movement of the droplet in the acoustic field. Therefore the followings are the purposes of present study. At first, the characteristics of droplets holding by the ultrasonic standing wave under normal gravity environment and micro-gravity environment is investigated. Secondary, numerical simulation is conducted to clarity the characteristics of ultrasonic standing wave. Finally, the force committed to a droplet is investigated by reproducing a movement of the droplet.
著者
阿部 豊 青木 一義
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:03875016)
巻号頁・発行日
vol.70, no.692, pp.1072-1077, 2004-04-25 (Released:2011-03-03)
参考文献数
4
被引用文献数
1 4

It is expected to manufacture new materials under the micro-gravity environment. Under the micro-gravity environment, holding technology of molten metal is important to manufacture new materials. In the present study, the technology to handle the material in space by the ultrasonic wave is developed. However, it is difficult to hold a high temperature object by ultrasonic standing wave due to temperature gradient. Moreover, it is also important to measure the physical properties of the material by non-contacting. Therefore the followings are the purposes of present study. At first, the characteristics of droplets holding by the ultrasonic standing wave under normal gravity environment is investigated. Secondly, the surface tension of the droplet is estimated by measuring surface oscillation. Thirdly, the viscous coefficient of liquid droplet is calculated by the damping constant of the droplet. Finally, numerical calculation is conducted to clarity the characteristics of the high temperature object holding in space.
著者
市川 昌弘 高松 徹 松尾 貴史 岡部 永年 阿部 豊
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.42, no.483, pp.1406-1411, 1993-12-15
被引用文献数
2 2

Rolling fatigue tests were carried out on hot isostatically pressed silicon nitride bearing balls.At three load levels of the maximum Hertzian contct pressure p_<max>=5900,6740 and 7110 MP_a,13 balls each were tested,and the life distribution was studied.It was found that the rolling fatigue life followed approximately a 2-parameter Weibull distribution with the shape parameter of a 〓 1 at each load level.The relationship p^k_<max>L_<50>=const(x〓10) was found between p_<max> and the median life L_<50>.Microscopic observationof flaking was also performed,and two types of flaking were found.One is flaking with the depth of the order of 100μm,and the other is a shallower one.The depth of the former type was found to coincide aproximately with the depth at which the maximum shear stress ocurred.At lower load levels,the former type was dominant.Frequency of appearance of the latter type increased with an increase in load level.Comparing the shape parameter of a〓1 and the exponent of x〓10 mentioned above with those for the cylic bending fatigue of plain specimens of silicon nitride,it was suggested that the mechanism of rolling fatigue of silicon nitride was different from that of cyclic bending fatigue of the same material.
著者
湯淺 朋久 阿部 豊 平野 覚
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 (ISSN:21879761)
巻号頁・発行日
vol.83, no.849, pp.16-00551-16-00551, 2017 (Released:2017-05-25)
参考文献数
11
被引用文献数
2

Toward the improvement of performance of an electric vehicle (EV), the design of the motor shape appropriate to heat removal is important. A typical EV motor is composed of a pair of coaxial cylinders with a fixed outer cylinder (stator) and a rotating inner cylinder (rotor). Some EV motors have axial slits on the stator wall. The present study experimentally clarifies the influence of inner shape on flow behavior in the EV motor. We divided the measurement area into three regions: the gap region, the rotor end region, and the gap end region. The flow behavior was recorded by a high-speed video camera and was measured via PIV. The flow behavior in the gap and rotor end regions were observed by Kalliroscope flakes. Taylor-Couette flow was observed in the gap region for the both cases without and with slits. In the rotor end region, the vortex that spirally flows from outer cylinder to the inside cylinder was observed. The white dye, injected in the gap, remained at the injection point for the cases without slits. However, the dye moved from the gap region to the rotor end region for the cases with slits. The vortex structure directed to the rotating axis was observed in the slit on the stator wall; the vortex had the axial velocity from the gap region to the rotor end region.
著者
谷脇 徹 興津 真行 細田 浩司 阿部 豊
出版者
東京農工大学
雑誌
フィールドサイエンス (ISSN:13473948)
巻号頁・発行日
vol.3, pp.25-30, 2003-03-25
被引用文献数
2 1

マツノマダラカミキリの羽化脱出消長を,東京都府中市では供試丸太をビニールシートで被ったビニ区で1999〜2002年に,林内区で2001年と2002年に,林外区と25℃恒温条件の恒温区で2002年に,茨城県那珂郡那珂町の林内区と茨城県下館市の林外区で1999〜2002年に調査した。供試丸太の網室搬入時期は,那珂町と下館市では冬期の伐倒直後であったが,府中市では5月下旬〜6月上旬であった。すべての調査区を設けた2002年の府中市では,脱出初日は林外区,50%羽化日は恒温区が最も早く,脱出初日から最終日までの日数は林外区で最も多く,ビニ区で最も少なくなり,同一地域でも環境や処理方法を変えると羽化脱出の傾向が異なることが確認された。4年間調査を行った府中市のビニ区,那珂町の林内区,下館市の林外区を比較すると,50%羽化日の平均は下館市が最も早く,有効積算温量が最も小さかった。林外では直射日光の影響でカミキリが実際に得る温量が多くなり,羽化脱出時期も早くなると考えられた。性比は高温少雨の年には小さくなった。また,府中市のビニ区と下館市の林外区では2000年から2002年にかけて同様の傾向を示した。
著者
阿部 豊 新井 崇洋
出版者
日本機械学会
雑誌
日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B (ISSN:03875016)
巻号頁・発行日
vol.71, no.702, pp.658-665, 2005-02-25

Spontaneous vapor explosion can occur when a layer of the high temperature molten material lies on the water pool or on the moisture floor. This is so-called base-triggered vapor explosion. The base-triggered vapor explosion is supposed to occur in the case of a severe accident in various industrial facilities. It is very important to clarify the occurrence condition and possibility of the base-triggered vapor explosion from the viewpoints of the prediction and the prevention of the vapor explosion. In order to evaluate the occurrence conditions and to clarify the micro-mechanism of the base-triggered vapor explosion, the experimental apparatus to observe the base-triggered vapor explosion from the bottom of the floor to above is designed and constructed. The experiments using U-Alloy95 as a simulant material are conducted. Consequently, the microscopic behavior at the interface between the molten material and water can be observed in detail with this experimental apparatus. The interfacial behavior of the molten material is quantitatively evaluated by the PIV analysis and the digital auto-colrrelation method with the experimental results. The blowout velocity of the molten material at vapor explosion is evaluated from the visual data obtained on the experiment. The generated pressure at the vapor explosion is estimated by using the blowout velocity. In addition, occurrence condition of the base-triggered vapor explosion is evaluated with the thermal interaction zone (TIZ) theory.
著者
新井 崇洋 阿部 豊 佐藤 健一郎 中川 裕二
出版者
一般社団法人日本機械学会
雑誌
年次大会講演論文集 : JSME annual meeting
巻号頁・発行日
vol.2004, no.3, pp.221-222, 2004-09-04

Spontaneous vapor explosion can occur when a layer of the high temperature molten material lies on the water pool or on the moisture floor. This is so-called base-triggered vapor explosion. The base-triggered vapor explosion is supposed to occur in the case of a severe accident in a nuclear reactor and in other industrial facilities. It is very important to clarify the base-triggered vapor explosion from the viewpoints of the prediction and the prevention of the vapor explosion. In order to evaluate the heat transfer and fluid dynamic behavior of the base-triggered vapor explosion, the experimental apparatus is designed and constructed. The experiments using U-Alloy95 as a stimulant material are conducted. Consequently, the behavior of the molten material can be observed in detail with this experimental apparatus. The digital auto-correlation method and PIV are also applied to the visual observation data obtained on the experiments in order to evaluate the velocity distribution of the molten material. Based on the velocity, the conversion ratio of kinetic energy in initial thermal energy at the vapor explosion is also evaluated. In addition, the experimental results are compared with the thermal interaction zone (TIZ) theory in order to evaluate the occurrence condition of base-triggered vapor explosion.
著者
阿部 豊雄 岩本 美代喜 祐川 淑孝 稲吉 浩 青野 正道
出版者
国立極地研究所
雑誌
南極資料 (ISSN:00857289)
巻号頁・発行日
vol.38, no.3, pp.268-321, 1994-11
被引用文献数
1

この報告は第32次南極地域観測隊気象部門が, 1991年2月1日から1992年1月31日まで昭和基地において行った気象観測の結果, 1990年12月26日から1991年12月1日までのあすか観測拠点における気象観測の結果ならびに, 1990年11月から12月に行った「しらせ」船上でのオゾン観測結果をまとめたものである。観測方法, 設備, 結果の取扱い等は, 昭和基地及びあすか観測拠点とも第31次観測隊とほぼ同じである。なお, 昭和基地では, 紫外線B領域の観測を始めるなど地上放射観測の充実を図った。あすか観測拠点では, 南極気候変動研究計画の一環として気水圏研究部門が計画した, オメガゾンデによる高層気象観測を16回実施した。越冬期間中特記される気象現象としては, 次のものがあげられる。1) 昭和基地ではブリザードの襲来が34回あり, あすか観測拠点におけるブリザード日数は82日間あった。2) 昭和基地における年間の日照時間の合計値は観測開始以来最も少ない1684.9時間であった。3) 3年連続でオゾンホールを観測し, 日別値では9月30日のオゾン全量が159m atm-cmと観測開始以来2番目に低い値を記録した。4) 5月23日, 昭和基地付近でハイドローリックジャンプによる雪煙の渦塔が観測された。