研究者詳細 - 坪井　伸幸

口頭発表・ポスター発表等 - 坪井　伸幸

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強度可変酸化剤流旋回型ハイブリッドロケットにおける酸化剤軸・接線噴射の非定常数値解析

後藤祥太, 小澤晃平, 宇崎友規, 西川佳希, 坪井伸幸

日本機械学会九州支部講演論文集

加速度環境におけるワックス燃料の境界層燃焼可視化実験へ向けた着火方法の検討

吉野拓郎, 小澤晃平, 坪井伸幸

日本機械学会九州支部講演論文集

二成分Lennard－Jones流体における対応状態原理の成立性

髙橋竜二, 坪井伸幸, 徳増崇, 津田伸一

日本機械学会九州支部講演論文集

酸水素混合系の音速に対する古典的混合則の精度検証

髙橋竜二, 坪井伸幸, 徳増崇, 津田伸一

年次大会

開催期間： 2018年01月記述言語：日本語

In the computational fluid dynamics (CFD) analyses for the combustion chamber of typical liquid rocket engine, for the prediction of thermophysical properties of mixture system, classical mixing rule (CMR) is applied to cubic equation of state (EOS) for single-component. However, the validation of CMR has been hardly conducted because of few experimental data. Therefore, we have conducted the validation of CMR coupled with the Soave–Redlich–Kwong (SRK) EOS as one of the cubic EOSs for the sound speed of oxygen-hydrogen mixture system in supercritical state using molecular dynamics (MD) simulation with the NVEPG ensemble. We have validated the accuracy of CMR through the comparison of the sound speed obtained by MD simulations with that obtained by CMR coupled with the SRK EOS. As a result, we confirmed that the sound speed obtained from SRK EOS coupled with CMR corresponded with that obtained from MD simulations. Further, the relative difference in sound speed between the MD simulations and SRK EOS hardly increased against single-component fluids. This result indicates that the CMR can be applied for the sound speed of oxygen–hydrogen mixture system in supercritical condition.

CiNii Article

実験によるCH4/O2デトネーションの伝播限界に当量比が与える影響の調査

井上卓, 吉田啓祐, 森井雄飛, 村上清人, 坪井伸幸, 林光一

日本機械学会九州支部講演論文集

再使用観測ロケットの空力特性に関する数値解析及び風洞試験

西川佳希, 牟田智幸, 坪井伸幸, 伊藤隆, 野中聡

日本機械学会九州支部講演論文集

二次元数値解析によるローテーティングデトネーションエンジンの内部流れ場の解明：非理想形噴射口の影響調査

塚本真章, 江藤成一朗, 坪井伸幸, 小島孝之, 林光一

日本機械学会九州支部講演論文集

オービターを搭載したWaveriderの空力特性に関する数値解析及び風洞試験

宇崎友規, 牟田智幸, 坪井伸幸, 丸祐介, 藤田和央

日本機械学会九州支部講演論文集

Mixing Characteristics of a Recessed Coaxial Jet at Supercritical Pressure

Daiki Muto, Hiroshi Terashima, Nobuyuki Tsuboi

AIAA SciTech2016

高圧水素噴流の拡散過程の３次元数値解析

藤本啓佑, 武藤大貴, 坪井伸幸, 朝原誠

流体工学部門講演会講演論文集

開催期間： 2016年01月記述言語：日本語

Three-dimensional numerical simulation of high pressure hydrogen jet is performed. Hydrogen leakage from the high pressure hydrogen tank has a possibility of serious explosion accidents. Therefore, it is necessary to understand diffusion behavior and ignition characteristics of hydrogen leakage. The present study simulates the high-pressure hydrogen supersonic free jet into the atmosphere to understand the dispersion process. As a result, the Jet flow fluctuates greatly in the radial direction and hydrogen disperses in a wide sphere. Also, lambda vortex structure was found to perform a crucial function in the diffusion of hydrogen.

CiNii Article

液体燃料ロケットタンク破壊時の推進剤ジェット・主流の干渉メカニズムに関する数値解析

岩佐聡洋, 武藤大貴, 藤本圭一郎, 坪井伸幸

年次大会

開催期間： 2016年01月記述言語：日本語

Numerical simulations of the jet injected into supersonic cross-flow are carried out. In aborting process in liquid rocket flight, the fuel is transversely injected into the supersonic freestream. Developed jet/freestream interaction structure may trigger unexpected auto-ignition or explosion events; thus the understanding of the flow-field of jet-in-supersonic cross-flow is essential to meet the reliability of rocket. The two-dimensional numerical simulations are carried out in a wide-range of jet and freestream conditions: the jet-to-freestream momentum flux ratio and the pressure ratio. Present result shows recirculation regions are formed both at the upstream and downstream of injector with the characteristic vortex structures. With increasing the jet-to-freestream momentum flux ratio, the vortex structures in the recirculation region are largely developed. It is founded that the highest temperature in the separation region depends on the total temperature in the separation region and furthermore, it is the lower temperature than the total temperature of freestream.

CiNii Article

Aerodynamic Characteristics Study on Waverider for Applying to TSTO

Tomoyuki Muta, Haruka Etoh, Nobuyuki Tsuboi, Yusuke Maru, Kazuhisa Fujita

30th International Symposiumon Space Technokigy and Science

Characteristics of Jet-Mixing at Supercritical Pressure for Coaxial Rocket Injector Design

Daiki Muto, Nobuyuki Tsuboi, Hiroshi Terashima

30th International Symposiumon Space Technokigy and Science

Evaluation of Thrust Performance on Rotating Detonation Engine for a JP10-Air Mixture

Wataru Yoshida, Makoto Asahara, Nobuyuki Tsuboi, A.Koichi Hayashi

30th International Symposiumon Space Technokigy and Science

Effects of the Recess Length on Supercritical Jet Mixing of Co-planar/axial Injectors

Daiki Muto, Nobuyuki Tsuboi, Hiroshi Terashima

6th European Conference forAeronautics and Space Sciences(EUCASS 2015)

Effects of Injector Geometry on Co-Flowing Planar Jet Mixings under Supercritical Pressures

Daiki Muto, Nobuyuki Tsuboi, Hiroshi Terashima

AIAA SciTech2015

Near propagation limit behavior of CH4/O2 Detonation in round tube:influence of equivalent ratio and tube diameter

Keisuke Yoshida, Koichi Hayashi, Youhi Morii, Kiyoto Murakami, Akio Susa, Nobuyuki Tsuboi A. Koichi Hayash

The 5th International symposium on Energetic Materials and their applications

Numerical simulation of thrust performance estimation on rotating detonation engine : The effects of nozzle on Isp

Yusuke WATANABE, Seiichiro ETOH, Nobuyuki TSUBOI, Takayuki KOJIMA, A. Koichi HAYASH

The 5th International symposium on Energetic Materials and their applications

Interaction between Shock Wave and Spherical Flme in Ethylene/Air Mixture and Transition to Detonation

Takayuki Araki, Youhi Morii, Nobuyuki Tsuboi, Koichi A. Hayashi

The 5th International symposium on Energetic Materials and their applications

Numerical Simulation on Unsteady Compressible Low-Speed Shear Flow in Hybrid Rocket Combustion Chamber Using Preconditioned Method: Effects of Preconditioned Method Including Multi-Species Mass Conservation Equations

Nobuyuki Tsuboi

Eleventh International Conference on Flow Dynamics

Numerical study of cryogenic coaxial jet under supercritical condition

Muto D., Tsuboiy N., Terashimaz H.

52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014

開催期間： 2014年01月01日記述言語：英語

Effects of recess on the mixing of the cryogenic coaxial jet under supercritical conditions were numerically investigated. Recessed injectors have been applied as coaxial injectors of liquid rocket engines because it is expected to improve propellant mixing and combustion efficiency. In the present study, a numerical simulation code was developed to examine jet mixing under the supercritical pressures. For validation of the present method, a two-dimensional planner jet simulation was carried out. The present result showed good agreement with an experimental result. As a preliminary study of coaxial jets, co-planner simulations were performed in a recessed case and an unrecessed case. Large-scale vortical structures were observed in the both cases, and the recessed case showed the larger struc- tures relative to the unrecessed case. This is because of the destabilization mechanism of a recessed region. These instabilities improved entrainments of ambient uid, and as a result, the enhanced jet mixing shortens the jet-core length.

Numerical Study of Cryogenic Coaxial Jet under Supercritical Condition

D. Muto, N. Tsuboi, H. Terashima

AIAA SCITECH2014

Numerical Simulation on Unsteady Compressible Low-Speed Flow Using Preconditioning Method: Preconditioning Method Including Multi-Species Mass Conservation Equations

Nobuyuki Tsuboi

Tenth International Conference on Flow Dynamics

Detailed Investigation on the Wave Structures in Ethylene/Oxygen Detonations in Narrow Channels

T. Araki, Y. Morii, N. Tsuboi, A.K. Hayashi

9th International High Energy Materials

Numerical Analysis of Spinning Detonation Dependency on Initial Pressure Using AUSMDV Scheme

Tsuyoshi Nagao, Makoto Asahara, A. Koichi Hayashi, Nobuyuki Tsuboi, Eisuke Yamada

51th AIAA Aerospace Sciences Meeting

Three-dimensional Numerical Simulation on Unsteady Compressible Flow Using Preconditioning Method in Hybrid Rocket Engine: Effects of Preconditioning Schemes

N.Tsuboi, K.Fukiba, T.Shimada

Ninth International Conference on Flow Dynamics (ICFD2012)

極超音速流れにおける30°ランプ周りの流れ場の3次元数値解析：平板幅の影響

倉本健史，武藤大貴，坪井伸幸，永井大樹( 東北大)，浅井圭介

日本機械学会九州支部第65期総会・講演会，812, 2012.3.

メタン酸素及び水素酸素燃料を用いた狭い管内を伝播する爆轟波の二次元数値解析

森井雄飛, 坪井伸幸, 小川博之, 寺島洋史, 徳留真一郎, 林光一

平成23年度衝撃波シンポジウム，1B2-4, 2012.3

重み付きコンパクトスキームを用いた2次元デトネーションの数値解析：高解像度スキームによる流れ場の詳細構造

坪井伸幸, 朝原誠, 野々村拓, 林光一

平成23年度衝撃波シンポジウム，1B2-6, 2012.3

2次元円筒デトネーションにおけるSub TransverseWaveの発生と発達

朝原誠, 林光一, 山田英助, 坪井伸幸

平成23年度衝撃波シンポジウム，1B2-6, 2012.3.

水素/空気デトネーションにおける反応モデルの影響の評価

杉安孝幸, 森井雄飛, 坪井伸幸, 林光一

平成23年度衝撃波シンポジウム，3B2-5, 2012.3.

低Re数における前処理型非定常圧縮性流れ場解析によるNACA0012翼型の空力特性評価

村田健輔, 坪井伸幸, 吹場活佳, 嶋田徹

日本機械学会九州学生会(2012) 第43回学生員卒業研究発表講演会, 439, 2012.3

LESによる超臨界流体噴流の流体力学的挙動に関する数値解析

瀬戸口，武藤，寺島，坪井，越

日本機械学会九州学生会(2012) 第43回学生員卒業研究発表講演会, 434, 2012.3

前処理型非定常圧縮性解法による噴流構造の数値解析

武藤大貴，瀬戸口彬，寺島洋史，坪井伸幸，越光男

日本機械学会九州支部第65期総会・講演会，803, 2012.3.

数値解析を用いたエアロスパイクノズルの性能評価：圧力比の影響

成宮匡，坪井伸幸，伊藤隆

日本機械学会九州支部第65期総会・講演会，812, 2012.3.

Three-Dimensional Numerical Simulation on Unsteady Compressible Flow Using Preconditioning Method: Swirling Injector Flowfield in Hybrid Rocket Engine

Nobuyuki Tsuboi, Katsuyoshi Fukiba, Toru Shimada

Eighth International Conference on Flow Dynamics (ICFD2011),OS5-15(pp.312-313)

Lewis number effect on DDT process and detonation

E. Dzieminska, A. K. Hayashi, N. Tsuboi

The 4th International Symposium on Energetic Materials and their Applications, 16-B1-4, 2011.11

Numerical approach to one-dimensional CH4/O2 detonation with the reduction model DRG30

Youhi Morii, Nobuyuki Tsuboi, Hiroyuki Ogawa,Shinichiro Tokudome, and A. Koichi Hayashi

The 4th International Symposium on Energetic Materials and their Applications, 17-A1-1, 2011.11

Three-dimensional simulation on a rotating detonation engine: Three-dimensional shock structure

N. Tsuboi, T. Yamada, A. K. Hayashi, E. Yamada

The 4th International Symposium on Energetic Materials and their Applications, 18-H-2, 2011

A Molecular Study on the Thermodynamic Properties of Cryogenic Hydrogen

Hiroki Nagashima, Takashi Tokumasu, Shinichi Tsuda, Nobuyuki Tsuboi and A. Koichi Hayashi

Seventh International Conference on Flow Dynamics, CRF-39, 2010

Numerical simulation of a bio-fuel/air two-phase detonation -propagation mechanism using ethanol-

T. Shimada, A.K. Hayashi, E. Yamada N. Tsuboi

Eighth International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions, ISH103, 2010

Computational study on cell bifurcation in two-dimensional cylindrical detonation using AUSMDV scheme

M. Asahara, N. Tsuboi, A.K. Hayashi E.Yamada

Eighth International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions, ISH105, 2010

Three-dimensional simulations of H2/O2 detonation in a round bent tube

N. Tsuboi, A.K. Hayashi, M. Uchida, T. Fujimori

Eighth International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions, ISH106, 2010

The effects of the schemes in inviscid flux on spinning detonation in a round tube

Y. Morii, M. Asahara, N. Tsuboi, A.K. Hayashi, M. Koshi, H. Ogawa, S. Tokudome

Eighth International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions, ISH101, 2010

The Molecular Simulation of Cryogenic Hydrogen Using Classical Method

Hiroki Nagashima, Takashi Tokumasu, Shin-ichi Tsuda, Nobuyuki Tsuboi, Mitsuo Koshi, A. Koichi Hayashi

1st IUPAC International Conference on Chemical Thermodynamics, ICCT2010-TS-3200-1740, 2010

Construction of a reliable reduced CH4/O2 chemical reaction model under high pressure states

Youhi Morii, Nobuyuki Tsuboi, Mitsuo Koshi, Hiroyuki Ogawa,A. Koichi Hayashi, Taro Shimizu

AJCPP2010-084, Asian Joint Conference on Propulsion and Power 2010, Miyazaki, 2010.3

Nonintrusive Diagnostics of Distribution of AP Particles in Composite Propellants

Hiroshi Hasegawa,Kazushige Kato, Hideo Miyachi, Mihoko Fukunaga,Nobuyuki Tsuboi, Yuzou Yajima,Katsumi Hiraoka,Yu Daimon,Toru Shimada

AJCPP2010-115, Asian Joint Conference on Propulsion and Power 2010, Miyazaki, 2010

Advanced Computer Science on Internal Ballistics of Solid Rocket Motors: 2009 Progress Report

Toru Shimada, Kazushige Kato, Nobuhiro Sekino, Nobuyuki Tsuboi,Hiroshi Hasegawa, Mihoko Fukunaga, Yu Daimon, Hiroya Asakawa

AJCPP2010-117, Asian Joint Conference on Propulsion and Power 2010, Miyazaki, 2010.3

Numerical Simulation on Unsteady Compressible Low-Speed Flow Using Preconditioning Method: Comparison between AUSMDV and AUSM+-up

Nobuyuki Tsuboi, Katsuyoshi Fukiba, Toru Shimada

AJCPP2010-088, Asian Joint Conference on Propulsion and Power 2010, Miyazaki, 2010.3

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<坪井 伸幸>

口頭発表・ポスター発表等 - 坪井 伸幸

<坪井　伸幸>

口頭発表・ポスター発表等 - 坪井　伸幸