Papers - MATSUI Jun
about 28-
二本の吸込管を有するポンプ吸込水槽における連結渦
松井純、近松天志郎
ターボ機械 53 113 - 120 2025.2 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work
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Chain-reaction collapse of cavitation clouds in Francis turbine runner during start-up
Mukai, T; Nakazono, M; Hashidate, T; Uchida, T; Tezuka, K; Matsui, J
32ND IAHR SYMPOSIUM ON HYDRAULIC MACHINERY AND SYSTEMS 1411 2024
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work
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Generation Mechanism of the Impulsive Pressure Rise during Start-up on Blade at High Head Low Specific Speed Francis Turbine
Turbomachinery 51 ( 4 ) 220 - 227 2023.4 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Single Work
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Generation Mechanism of the Impulsive Pressure Rise during Start-up on Blade at High Head Low Specific Speed Francis Turbine
MUKAI Takero, NAKAZONO Masahiko, HASHIDATE Tadayuki, UCHIDA Tatsuro, TEZUKA Kotaro, MATSUI Jun
Turbomachinery 51 ( 4 ) 220 - 228 2023
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Turbomachinery Society of Japan Joint Work
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A New Simplified Performance Conversion Method for Hydraulic Turbines and Pump-Turbines
Yuji NAKANISHI, Jun MATSUI, Kaneo SUGISHITA, Yoshiichirou HAYASHI, Takanori NAKAMURA, Toshiaki SUZU … Show more authors
Yuji NAKANISHI, Jun MATSUI, Kaneo SUGISHITA, Yoshiichirou HAYASHI, Takanori NAKAMURA, Toshiaki SUZUKI, Ryoji SUZUKI, Kiyohito TANI Hide authors
Turbomachinery 49 ( 4 ) 229 - 240 2022.3 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Publisher：Turbomachinery Society of Japan Joint Work
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Numerical Analysis on the Effect of J-groove on Flows in Narrow Gaps between Rotating Disk and Casing
Nguyen Vo Dao, Matsui Jun
International Journal of Fluid Machinery and Systems 15 ( 1 ) 64 - 74 2022.1 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Publisher：ターボ機械協会、韓国流体機械学会、中国工程熱物理学会、国際水理学会 Joint Work
During operation and working of turbo machines, axial thrust balancing is important. To control and balance the axial thrust, a very simple method using shallow radial grooves mounted on the casing wall, called “J-groove”, was proposed, and studied experimentally[1]. This paper presents a numerical study of the effect of J-groove on the flow in the narrow gap along enclosed rotating disks based on open-source CFD software. It is seen that the difference in pressure between the hub and shroud tip is increased with the increasing number, depth, and length of J-groove. But in the case of increasing width of J-groove, the pressure loss along the radius decreases when the ratio of the groove width to the outer radius W is less than 0.2 and increases when W greater than 0.2.
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Specific Internal Flow in Balancing Hole
YAMASHITA Yosuke, MATSUI Jun, OKUBO Atsushi
Turbomachinery 47 ( 12 ) 723 - 729 2020.3 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Turbomachinery Society of Japan Joint Work
<p>In order to research the discharge coefficient of a balancing hole <i>C<sub>d</sub></i> for a wide range of axial flow velocity <i>v</i> in the hole and rotational speed <i>u</i>, we carried out CFD simulations. Some of the results and the reported experimental data agree within the difference of about 5.3% on the pressure difference of the hole. Flow in a balancing hole is influenced by not only <i>v</i> but also <i>u</i>. Therefore the parameter <i>v</i>/<i>u</i> is considered as an important parameter of <i>C<sub>d</sub></i>. Furthermore, for very low range of <i>v</i>/<i>u</i>, we found a rare flow situation with S-shaped streamlines. Due to the strong pumping effect by rotating disk, <i>C<sub>d</sub></i> is greatly different in this region.</p>
Other Link： https://ci.nii.ac.jp/naid/130007818387
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Suction Vortices in a Pump Sump-Their Origin, Formation, and Dynamics
Yamade Yoshinobu, Kato Chisachi, Nagahara Takahide, Matsui Jun
JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME 142 ( 3 ) 031110-1 - 031110-26 2020.3 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Joint Work
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LARGE EDDY SIMULATION OF A SUBMERGED VORTEX IN A SIMPLIFIED COMPUTATIONAL MODEL
Yamade Yoshinobu, Kato Chisachi, Nagahara Takahide, Matsui Jun
PROCEEDINGS OF THE ASME/JSME/KSME JOINT FLUIDS ENGINEERING CONFERENCE, 2019, VOL 3B 3B 2019.11 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Joint Work
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Flow structure of a submerged vortex in a pump sump
YAMADE Yoshinobu, KATO Chisachi, NAGAHARA Takahide, MATSUI Jun
Transactions of the JSME (in Japanese) 85 ( 878 ) 19 - 00294-19-00294 2019.10 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Society of Mechanical Engineers Joint Work
<p>The flow structures of a submerged vortex that appears in a model pump sump have been fully clarified by performing large eddy simulation (LES) of a model vortex in a simplified computational model. The computational model had a sufficiently fine grid that could resolve the vortex core. The model sump is composed of a 2,500 mm-long water channel of rectangular cross section with a width of 300 mm and a water height of 150 mm and a vertical suction pipe with a 100 mm diameter installed at its downstream end. Our previous large eddy simulations (LES), which used approximately 2 billion grids and were applied to the whole pump sump, has fully clarified the origin and formation mechanism of a submerged vortex and an air-entrained vortex. In these computations, however, the static pressure in the vortex core decreased by only 5 kPa at a channel velocity of 0.37 m/s. The decrease in the static pressure was far smaller than the one for which one can expect initiation of cavitation in the vortex core. In the corresponding experiment, however, appearance of a submerged vortex was confirmed by the occurrence of cavitation in the vortex core. Therefore, the decrease in the static pressure is most likely to be underpredicted in our previous LES. Insufficient grid resolution was assumed to be one of the reasons for this underprediction. In the present study, LES with a sufficiently fine grid was applied to a simplified computational model that represents the stretch of a submerged vortex under a constant acceleration of the vertical velocity. Vertical and tangential velocities obtained by averaging those profiles of a submerged vortex computed in the previous LES were prescribed at the bottom wall of the computational domain as the inflow boundary conditions. In the present LES, the static pressure has decreased by more than 100 kPa. In addition, parametric studies with different initial swirl numbers varied from 0.08 to 10.9 have fully clarified the behavior of a submerged vortex. It is found that a strong submerged vortex appears only at a relatively small range of the swirl-number from 0.8 to 2.</p>
Other Link： https://ci.nii.ac.jp/naid/130007733868
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Formation mechanism of suction vortices in a pump sump
YAMADE Yoshinobu, KATO Chisachi, NAGAHARA Takahide, MATSUI Jun
Transactions of the JSME (in Japanese) 85 ( 875 ) 19 - 00072-19-00072 2019.7
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Society of Mechanical Engineers Joint Work
<p>The origin and formation mechanism of a submerged vortex and an air-entraining vortex have been fully clarified by large-eddy simulation (LES) that used approximately 2 billion hexahedral elements with maximum resolution of 0.255 mm and was applied to the internal flows of a model pump sump. The model pump sump is composed of a 2,500 mm-long water channel of rectangular cross section with a width of 300 mm and a water depth of 100 mm and a vertical suction pipe with a 100 mm diameter installed at its downstream end with an offset of 10 mm from the centerline of the rectangular channel. At the upstream end of the channel, a uniform velocity of 0.37 m/s is given. LES with different wall boundary conditions have revealed that the origin of a submerged vortex is the mean shear of the approaching boundary layers that develop on the bottom and side walls of the pump sump. From detailed investigations of LES computed for a long time period of 16 seconds have revealed that deviation of the mean flow that approaches the suction pipe triggers conversion of the axis of the vorticity that was originally aligned to the lateral direction in the approaching boundary layers to that aligned to the vertical direction. The local acceleration of the vertical flow stretches the afore-mentioned vertical vortex, which results in formation of a submerged vortex. The separated flows downstream of the suction pipe generate vertical vorticity, and forms an air-entraining vortex when such a vortex is sucked into the suction pipe. Computations with a different bellmouth height and a different water-surface height have supported the above mentioned origin and formation mechanism of these vortices.</p>
Other Link： https://ci.nii.ac.jp/naid/130007683177
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Numerical study on the flow in balancing hole
Jun Matsui, Atsushi Okubo and Yousuke Yamashita
IOP Conference Series: Earth and Environmental Science 2019.1 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Publisher：IOP Publishing Ltd Single Work
Other Link： https://doi.org/10.1088/1755-1315/240/2/022002
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Numerical study on the flow in balancing hole
Matsui Jun, Okubo Atsushi, Yamashita Yousuke
29TH IAHR SYMPOSIUM ON HYDRAULIC MACHINERY AND SYSTEMS 240 2019 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work
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Similarity on Occurrence Condition of Vortexes in Pump Sumps
MATSUI Jun
Turbomachinery 44 ( 4 ) 223 - 231 2016.4 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Turbomachinery Society of Japan Single Work
Other Link： https://www.jstage.jst.go.jp/article/tsj/44/4/44_223/_article/-char/ja/
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ポンプ吸込水槽に発生する水中渦のLES解析
山出 吉伸, 加藤 千幸, 長原 孝英, 松井 純
生産研究 68 ( 1 ) 69 - 73 2016.1 [Reviewed]
Language：Japanese Publishing type：Research paper (bulletin of university, research institution) Joint Work
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STABILITY OF AN AXIAL-THRUST SELF-BALANCING SYSTEM
Takashi Shimura, Satoshi Kawasaki, Masaharu Uchiumi, Toshiya Kimura,Mitsuaki Hayashi,Jun Matsui
Journal of Fluids Engineering Trans ASME 135 ( 1 ) 011105;1 - 7 2013.1 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Joint Work
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Numerical Analysis of the Unsteady Fluid Force Acting on an Axially Oscillating Balance Piston
Journal of the Japan Society of Mechanichal Engineers 78 ( 787 ) 588 - 597 2012.3 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Mechanichal Engineers Joint Work
Other Link： https://www.jstage.jst.go.jp/article/kikaib/78/787/78_787_588/_article/-char/ja/
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Internal Flow and Performance of the SpiralWater Turbine : 2nd Report
MATSUI Jun
Turbomachinery 40 ( 2 ) 91 - 96 2012.2 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Turbomachinery Society of Japan Single Work
Other Link： https://www.jstage.jst.go.jp/article/tsj/40/2/40_91/_article/-char/ja/
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Numerical Study on the Internal Flow and Torque\\ in Variable Capacity Type Fluid Coupling
MATSUI Jun
Transactions of the Japan Society of Mechanical Engineers, Series B 74 ( 739 ) 545 - 551 2008.3 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Single Work
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Study on Control of Axial Thrust in Centrifugal Pump by Use of J-Groove
MATSUI Jun, KUROKAWA Junichi, ABE Heishiro, MATSUMOTO Kazunari
Transactions of the Japan Society of Mechanical Engineers,series B 74 ( 738 ) 317 - 322 2008.2 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work
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可変液量型流体継手のトルク性能の緩慢な低下に関する研究
黒川 淳一、今村 博
ターボ機械 31 ( 12 ) 739 - 744 2003.12 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work
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Numerical Study of Molecular Scattering on the Thermal Equilibrium Surface with Adsorbates
Jun Matsui
Proc. of 23th International Symposium on Rarefied Gas Dynamics 1 957 - 964 2002.7 [Reviewed]
Language：English Publishing type：Research paper (international conference proceedings) Single Work
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低比速度遠心ポンプのセミオープン羽根車内部流れ
崔永都、黒川淳一、今村博、原学
日本機械学会論文集 68 ( 668 ) 1174 - 1180 2002.4 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work
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ターボ分子真空ポンプ内部流れの二次元数値シミュレーション
白井健二、黒川淳一
日本機械学会論文集 67 ( 661 ) 2159 - 2165 2001.9 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work
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半径比の大きなベーンレスディフューザにおける特異な旋回失速
黒川淳一，箕道治，広木英治，北洞貴也
日本機械学会論文集 51 ( 591B ) 3842 - 3847 1995.11 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work
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Numerical Analysis of an Atomic Molecule Interaction on Surface
Youichiro Matsumoto,Jun Matsui
Thermal Science and Engineering 2 ( 1 ) 28 - 34 1994 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Joint Work
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分子動力学法による気体-表面散乱の解析（第２報：Xe-Pt(111)系における動的挙動）
松本洋一郎、大橋秀雄
日本機械学会論文集 58 ( 553B ) 2744 - 2749 1992.1 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work
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分子動力学法による気体-表面散乱の解析（第１報：Lennard-Jones分子系によるシミュレーション）
松本洋一郎、大橋秀雄
日本機械学会論文集 58 ( 551B ) 2046 - 2051 1992 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Joint Work