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MIYAJI Koji
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【Published Thesis】 TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 2023
【Published Thesis】 Study on the Application of Fast Linear Matrix Solvers for Enhanced Efficiencies of Wing Flutter Analysis(Transactions of the Japan Society for Computational Engineering and Science) 2022.08
【Published Thesis】 Prediction of transonic 2D wing flutter using the time-spectral computational fluid dynamics(JOURNAL OF FLUID SCIENCE AND TECHNOLOGY) 2022.07
【Published Thesis】 TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 2022.02
【Published Thesis】 TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 2021.11
The University of Tokyo Department of Aerospace engineering Doctor Course Completed
The University of Tokyo Department of Aerospace Engineering Master Course Completed
Nagoya University Department of aeronautics Graduated
Doctor of Engineering - The University of Tokyo
Duty Yokohama National UniversityFaculty of Engineering Division of Systems Research Professor
Duty Yokohama National UniversityFaculty of Engineering Division of Systems Research Associate Professor
Duty Yokohama National UniversityFaculty of Engineering Division of Systems Research Associate Professor
Duty Yokohama National UniversityFaculty of Engineering Division of Systems Research Lecturer
Duty Yokohama National UniversitySchool of Engineering Lecturer
Research fellow of the center of excellence (COE) at the Institute of Space and Astronautical Science Researcher
Japan Society for Aeronautical and Space Sciences
Japan Society of Mechanical Engineering
Japan Socieyt of Fluid Mechanics
American Institute of Aeronautics and Astronautics
Frontier Technology (Aerospace Engineering, Marine and Maritime Engineering) / Aerospace engineering / Aerospace engineering
Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Fluid engineering / Compressible fluid dynamics
Others / Others / Computational fluid dynamics
Numerical Analysis of Shock Wave Reflection and Interaction Using Unstructured Solution Adaptive Grids
1997.3
Doctoral Thesis Single Work
デルタ翼の空力特性に及ぼすTrailing-Edge Lateral Blowingの効果
宮路 幸二
1994.3
Master Thesis Single Work
東京大学大学院 工学系研究科 航空宇宙工学専攻
デルタ翼の新たな空力特性改善手法として翼付近からの噴き出しを提案し、その効果を実験的、数値的に確認した。また、風洞実験との比較の過程において風洞側壁境界層がデルタ翼まわりの流れに影響を与えることを見出し、数値計算によりその影響を定量的に議論した。
Study on the Effects of a Wing Dihedral for the Reduction of Sonic Boom Intensity
TSUDA Takuma, MIYAJI Koji
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN 21 ( 0 ) 9 - 17 2023.1 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Publisher：一般社団法人 日本航空宇宙学会 Joint Work
<p>The effects of a wing dihedral on sonic boom reduction are systematically studied for a realistic supersonic transport. The LM1021, which was designed in detail by Lockheed Martin Corporation (U.S.A.), is used as the baseline analysis model. The aerodynamic coefficients and near-field pressure signatures are obtained using CFD for inviscid flows, and then the sonic boom intensity on the ground is calculated with the pressure wave propagation analysis by solving the augmented Burger's equation. The ‘Xnoise’ code developed by JAXA is used for the wave propagation analysis. The results clearly show a reduction in the sonic boom intensity not only on the undertrack, but also on the off-track. One representative result is that the pressure peak of the tail boom at the flight Mach number of 1.6 is reduced more than 15% by a 10-deg dihedral compared to a 0-deg dihedral at the cost of a 2% increase in drag. Variations of the lateral/directional static stability are also studied, and the results show improved lateral stability while there are mild directional instabilities caused by the dihedral.</p>
Study on the Application of Fast Linear Matrix Solvers for Enhanced Efficiencies of Wing Flutter Analysis
MIYAJI Koji, TAKEGAWA Hiroto, HAYASHI Kota
Transactions of the Japan Society for Computational Engineering and Science 2022 ( 0 ) 20220010 - 20220010 2022.8 [Reviewed]
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：JAPAN SOCIETY FOR COMPUTATIONAL ENGINEERING AND SCIENCE Joint Work
<p>This study enhances the efficiency and versatility of the flow simulations for moving and deforming bodies that are typically required for fluid-structured interactions such as flutter. Two of critically time-consuming processes are calculations of spatial grid deformations and nearest wall distances for the turbulence models. Both are formulated as elliptic boundary value problems, and the fast matrix solvers for the linear systems are developed and validated. One method is the flexible GMRES and another is the Residual Cutting Method (RCM). Two types of unstructured grids around practical aircraft model known as NASA Common Research Model (CRM) are used to test the developed method. Both GMRES and RCM are at least 4 times faster than the classical Gauss-Seidel method to achieve practical criteria of convergence. Errors of the nearest wall distance by the present method are within 5% except the portions of large curvature, and they have little effects on the flow simulations around CRM for a cruise condition without large-scale flow separations. Flutter simulations for a single wing are also carried out, and the results well predict the onset conditions of the flutter of the wind-tunnel experiment.</p>
Prediction of transonic 2D wing flutter using the time-spectral computational fluid dynamics
Miyaji Koji, Takegawa Hiroto
JOURNAL OF FLUID SCIENCE AND TECHNOLOGY 17 ( 2 ) 1 - 13 2022.7 [Reviewed]
DOI Web of Science CiNii Research
Language：English Publishing type：Research paper (scientific journal) Publisher：一般社団法人 日本機械学会 Joint Work
<p>A new computation method to predict a transonic wing flutter under the limit-cycle oscillation (LCO) is developed using the time spectral (TS) method. The fluid and structural unknowns at a specified time interval in one cycle of the flutter are obtained by steady-state solutions of the aeroelastic TS equations, and thus higher computational efficiency is expected. Determining the frequency is the key for the flutter prediction, and we propose a method of minimizing the residuals of the fluid equation. The time histories of the plunge and pitch are reconstructed by the discrete Fourier transform, and compared with the existing time marching (TM) method. The effects of the number of harmonics in the TS and the time-step size in the TM are examined for the detailed comparison. The frequency, amplitude, and phase differences between the structural vibration modes all well agree between the two methods for a wide range of flutter speed index. Complex flutter boundaries are also predicted. The TS method is faster to reach the LCO than the TM method for the first vibration mode of the flutter. It is slower for the second vibration mode, but the increase in the computation time is much smaller than the reduction in the first mode. In general, the TS method is particularly advantageous for the prediction near flutter boundaries and is useful for aircraft design.</p>
MIYAJI Koji, KOYAMA Hisato
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN 20 ( 0 ) 16 - 25 2022.2 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Publisher：一般社団法人 日本航空宇宙学会 Joint Work
<p>An efficient implicit time integration method for high-order CFD using the flux reconstruction (FR) approach is studied. The formulation is based on the method called matrix-free defect correction on sub-cells (DECS), which considerably reduces the computational cost of the preconditioned block LU-SGS (BLU-SGS). However, the present method uses the exact FR formulation for the simplified viscous terms in the left-hand-side Jacobian, and it does not explicitly use sub-cell divisions as a result of using the finite-difference formula. The performance of the proposed method is compared with BLU-SGS and DECS. Reductions of the computation time for the convergence are not remarkable, but the slightly improved stability and reduced memory storage suggest the present method as a reliable alternative to the existing methods.</p>
Program of High Mach Integrated Control Experiment, “HIMICO” Using S-520 Sounding Rocket
SATO Tetsuya, TAGUCHI Hideyuki, KOJIMA Takayuki, TSUCHIYA Takeshi, TSUE Mitsuhiro, NAKAYA Shinji, M … Show more authors
SATO Tetsuya, TAGUCHI Hideyuki, KOJIMA Takayuki, TSUCHIYA Takeshi, TSUE Mitsuhiro, NAKAYA Shinji, MATSUO Akiko, TEZUKA Asei, FUJIKAWA Takahiro, MIYAJI Koji Hide authors
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN 19 ( 6 ) 831 - 837 2021.11 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Publisher：一般社団法人 日本航空宇宙学会 Joint Work
<p>JAXA and some universities have proposed a hypersonic flight experiment named “HIMICO: High Mach Integrated Control Experiment” using a 1.5-meter class vehicle launched by the S-520 sounding rocket. The experiment aims to establish an integrated control method including the interference between the airframe and engine under the actual Mach 5 flight condition. Two flight experiments are planned step by step to reduce technical risks. Feasibility studies have been conducted by experiments and CFD analysis. This paper reports the summary of the flight test plan and preliminary studies on the vehicle shape, flight trajectory, component design and technical issues.</p>
次世代超音速旅客機の空力性能数値シミュレーション
日本流体力学会誌ながれ 21 ( 1 ) 1 - 2 2002.2
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (scientific journal) Single Work
時間スペクトル法による高速数値計算を用いたフラッターの不確実性評価の研究
2019.4 - 2022.3
科学研究費補助金 Grant-in-Aid for Scientific Research(C)
Grant type：Competitive
ラジエータファンまわりのCFD解析
2008.4 - 2011.3
Private Foundations
Investigator(s)：宮路幸二
Efforts to improve the practicality of flux reconstruction method CFD
MIYAJI Koji
Event date： 2024.1
Language：Japanese Presentation type：Oral presentation (general)
Aeroelastic numerical simulations
Numerical fluid simulations from incompressible flows to supersonic flows
観測ロケットS-520による極超音速統合制御実験（HIMICO）
Funded Research offered by Enterprises
Project Year： 2024.2 - 2026.2
近傍場圧力波形計測のための衝撃波／乱流境界層干渉に関する数値的研究
Funded Research offered by Enterprises
Project Year： 2011.8 - 2012.3
熱交換器の伝熱促進（境界層制御）に関する研究
Funded Research offered by Enterprises
Project Year： 2008.4 - 2011.3
Prediction of the Performance of Turbo Charger
Funded Research offered by Enterprises
Project Year： 2005.4 - 2009.3
Aerodynamic Characteristics of External Apparatus of Aircraft
Funded Research offered by Enterprises
Project Year： 2003.4 - 2004.3
2024 Aircraft Aerodynamic Design Ⅱ
Interfaculty Graduate School of Innovative and Practical Studies
2024 Studio of R&D in Ocean-Space Engineering A
Graduate school of Engineering Science
2024 Practical Training in Ocean and Space System Engineering
Graduate school of Engineering Science
2024 Practical Engineering Training in Ocean-Space
Graduate school of Engineering Science
2024 Overseas Training in Marine and Space System Engineering
Graduate school of Engineering Science
極超音速推進技術検討委員会
2020.6 - 2021.3 委員
Committee type：Other
Asia Pacific International Symposium on Aerospace Technology
2017.4 - 2020.3
Committee type：Academic society
