MIYAJI Koji

Affiliation

Faculty of Engineering, Division of Systems Research

Job Title

Associate Professor

Date of Birth

1970

Research Fields, Keywords

Compressible fluid dynamics, Aeroelastic dynamics, Aerospace engineering, Computational fluid dynamics

Mail Address

E-mail address



Education 【 display / non-display

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    1997

    The University of Tokyo   Department of Aerospace engineering   Doctor Course   Completed

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    1994

    The University of Tokyo   Department of Aerospace Engineering   Master Course   Completed

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    1992

    Nagoya University   Department of aeronautics   Graduated

Degree 【 display / non-display

  • Doctor of Engineering - The University of Tokyo

Campus Career 【 display / non-display

  • 2007.4
     
     

    Duty   Yokohama National UniversityFaculty of Engineering   Division of Systems Research   Associate Professor  

  • 2004.12
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    2007.3

    Duty   Yokohama National UniversityFaculty of Engineering   Division of Systems Research   Associate Professor  

  • 2001.4
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    2004.11

    Duty   Yokohama National UniversityFaculty of Engineering   Division of Systems Research   Lecturer  

  • 1999.4
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    2001.3

    Duty   Yokohama National UniversitySchool of Engineering   Lecturer  

  • 2021.4
     
     

    Concurrently   Yokohama National UniversityInterfaculty Graduate School of Innovative and Practical Studies   Associate Professor  

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External Career 【 display / non-display

  • 1997.4
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    1999.3

    Research fellow of the center of excellence (COE) at the Institute of Space and Astronautical Science   Researcher  

Academic Society Affiliations 【 display / non-display

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    Japan Society for Aeronautical and Space Sciences

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    Japan Society of Mechanical Engineering

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    Japan Socieyt of Fluid Mechanics

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    American Institute of Aeronautics and Astronautics

Research Areas 【 display / non-display

  • 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

 

Thesis for a degree 【 display / non-display

  • Numerical Analysis of Shock Wave Reflection and Interaction Using Unstructured Solution Adaptive Grids

    1997.3

    Doctoral Thesis   Single Work  

    DOI

  • 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  

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    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。

Papers 【 display / non-display

  • 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]

    DOI CiNii Research

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    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

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    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>

  • Efficient Implicit Method for a High-Order Flux Reconstruction Approach Using Modified Matrix-Free Defect Correction

    MIYAJI Koji, KOYAMA Hisato

    TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN   20 ( 0 )   16 - 25   2022.2  [Reviewed]

    DOI CiNii Research

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    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

    TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN   19 ( 6 )   831 - 837   2021.11  [Reviewed]

    DOI CiNii Research

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    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>

  • Prediction of Aeroelastic limit cycle oscillation by the time spectral CFD

    Hiroto Takegawa, Koji Miyaji

    2021 Asia-Pacific International Symposium on Aerospace Technology   2021.11

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    Language:English   Publishing type:Research paper (international conference proceedings)   Single Work  

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Review Papers 【 display / non-display

  • 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

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    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Single Work  

Grant-in-Aid for Scientific Research 【 display / non-display

  • 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)

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    Grant type:Competitive

Other external funds procured 【 display / non-display

  • 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

Preferred joint research theme 【 display / non-display

  • Aeroelastic numerical simulations

  • Numerical fluid simulations from incompressible flows to supersonic flows

Past of Collaboration and Commissioned Research 【 display / non-display

  • 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 

 

Charge of on-campus class subject 【 display / non-display

  • 2022   Introduction to Aerospace Engineering

    College of Engineering Science

  • 2022   Exercise in Aerospace Engineering D

    Graduate school of Engineering Science

  • 2022   Exercise in Aerospace Engineering C

    Graduate school of Engineering Science

  • 2022   Guidance and Control of Flight

    College of Engineering Science

  • 2022   Studio of Aerospace System B

    Graduate school of Engineering Science

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Committee Memberships 【 display / non-display

  • 極超音速推進技術検討委員会

    2020.6 - 2021.3  委員

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    Committee type:Other 

  • Asia Pacific International Symposium on Aerospace Technology

    2017.4 - 2020.3 

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    Committee type:Academic society