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2021/7 Vol.124

機構模型

工部大学校の「機械学」教育機器(機械遺産第100号)

角度定規

年代未詳/金属/W652, Dia.137(mm)/東京大学総合研究博物館所蔵

製図道具は近代化の進められた機械学教育に用いられた。本資料の年代や製作場所は未詳であるが、他に「工学寮」「工部省工作所」等の刻記から国内で製作されたことがわかる製図道具類が東京大学総合研究博物館に現存する。

上野則宏撮影/東京大学総合研究博物館写真提供/インターメディアテク展示・収蔵

[東京大学総合研究博物館]

バックナンバー

論文アクセスランキング

論文アクセスランキング 日本機械学会学術誌(英文) 年間アクセス数トップ10

(2020年1月~2020年12月の期間で集計) *順位の変動は2019年7月~2020年6月の期間との比較


Large eddy simulation with modeled wall-stress: recent progress and future directions

Johan LARSSON, Soshi KAWAI, Julien BODART, Ivan BERMEJO-MORENO

Mechanical Engineering Reviews(2016) DOI:10.1299/mer.15-00418
The paper provides a brief introduction to the near-wall problem of LES and how it can be solved through modeling of the near-wall turbulence. The distinctions and key differences between different approaches are emphasized, both in terms of fidelity (LES, wall-modeled LES, and DES) and in terms of different wall-modeled LES approaches (hybrid LES/RANS and wall-stress-models). The focus is on approaches that model the wall-stress directly, i.e., methods for which the LES equations are formally solved all the way down to the wall. Progress over the last decade is reviewed, and the most important and promising directions for future research are discussed.

A review of metal additive manufacturing technologies: Mechanism of defects formation and simulation of melting and solidification phenomena in laser powder bed fusion process

Hideki KYOGOKU, Toshi-Taka IKESHOJI

Mechanical Engineering Reviews (2020) DOI:10.1299/mer.19-00182
In this review, the analysis of melting and solidification phenomena and the mechanism of the occurrence of defects as well as the analysis of melting and solidification using the numerical simulation in laser powder bed fusion (LPBF) process were introduced. In addition, the strategies of suppression of defects were described. The melting and solidification phenomena during LPBF process are relatively similar to those during welding. Since the plume brings about the strong recoil pressure on the melt pool, the keyhole takes place. And when the depth of keyhole becomes more than a threshold, the keyhole pore remains at the bottom of melt pool. Since the plume also brings about spattering and blows out powder, the gas pores are prone to occur easily. The micro-simulation of melting and solidification enables to reproduce the real phenomena. The macro-simulation of melting and solidification phenomena is one of the effective tools to predict the optimum fabrication condition. In order to prevent the occurrence of defects, it is significant not only to obtain the optimum fabrication condition using the process map but also to develop the simulation software. In addition, the use of the monitoring and feedback control system is greatly effective. Therefore the development of the cyber-physical system is needed.

Three-dimensional deformation mode of multicellular epithelial tube under tension and compression tests

Satoru OKUDA, Katsuyuki UNOKI, Mototsugu EIRAKU, Ken-ichi TSUBOTA

Journal of Biomechanical Science and Engineering (2018) DOI:10.1299/jbse.17-00507
Deformability of epithelial tissues plays a crucial role in embryogenesis, homeostasis, wound healing, and disease. The deformability is determined by the mechanical balance between active force generation and passive response of cells. However, little is known about how multiple cells in epithelial tissues passively respond to external forces. Using a 3D vertex model, we performed computational simulations of longitudinal tension and compression tests of an epithelial tube. Under tension, the tube extended with necking as exhibiting cell rearrangements that play a role in reducing local stiffness of the tube. On the other hand, under compression, the tube buckled with kinking without cell rearrangements. The cell rearrangements occurred when apical and basal cell surfaces stored elastic deformation energies. These results illustrate the variance of deformation modes of epithelial tissues in the single cell level as well as the importance of cell rearrangements in regulating epithelial deformability.

4位

[↓]

Relationship between solidification time and porosity with directed energy deposition of Inconel 718

Tatsuhiko KURIYA, Ryo KOIKE, Takanori MORI, Yasuhiro KAKINUMA
Journal of Advanced Mechanical Design, Systems, and Manufacturing (2018) DOI:10.1299/jamdsm.2018jamdsm0104

5位

[→]

Scale model experiments for evaluation of liquid water transport in the gas diffusion layer of PEFCs

Yutaka TABE, Satoshi SAKAIDA, Takemi CHIKAHISA
Journal of Thermal Science and Technology (2018) DOI:10.1299/jtst.2018jtst0025

6位

[↑]

Aerodynamic drag change of simplified automobile models influenced by a passing vehicle

Keigo SHIMIZU, Takuji NAKASHIMA, Takenori HIRAOKA, Yusuke NAKAMURA, Takahide NOUZAWA, Yasuaki DOI
Mechanical Engineering Journal (2020) DOI:10.1299/mej.19-00366

7位

[NEW]

A review: controlling the propagation of surface acoustic waves via waveguides for potential use in acoustofluidics

Jiyang MEI, James FRIEND
Mechanical Engineering Reviews (2020) DOI:10.1299/mer.19-00402

8位

[NEW]

Sterilization in liquids by air plasma under intermittent discharge

Kairi MURAMATSU, Takehiko SATO, Tomoki NAKAJIMA, Toshikatsu NAGASAWA, Tatsuyuki NAKATANI, Shigeru FUJIMURA
Mechanical Engineering Journal (2020) DOI:10.1299/mej.19-00431

9位

[NEW]

Computational biomechanics of knee joint arthroplasty : a review

Kyoung-Tak KANG, Yong-Gon KOH, Jin-Ah LEE, Heoung-Jae CHUN
Mechanical Engineering Reviews (2020) DOI:10.1299/mer.19-00338

10位

[NEW]

Passive flow control of jets

Toshihiko SHAKOUCHI
Mechanical Engineering Reviews (2020) DOI:10.1299/mer.19-00386

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