Project/Area Number |
19K04182
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 19010:Fluid engineering-related
|
Research Institution | Nara National College of Technology |
Principal Investigator |
Fukuoka Hiroshi 奈良工業高等専門学校, 機械工学科, 准教授 (40582648)
|
Project Period (FY) |
2019-04-01 – 2024-03-31
|
Project Status |
Completed (Fiscal Year 2023)
|
Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2022: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2021: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2020: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000)
Fiscal Year 2019: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
|
Keywords | 圧縮性流体 / 超音速噴流 / 衝撃波 / 反射衝撃波 / 収束現象 / 閉じ込め / 可視化 / 3D数値解析 / 数値解析 / BOS法 / 反射制御 / 壁面形状 |
Outline of Research at the Start |
本研究では,工業,新エネルギー,材料開発で重要な課題である,衝撃波の多重閉じ込め現象を制御する壁面表面形状の設計指針の獲得と、その実験的実証を行う.噴流誘起衝撃波の壁面-噴流先頭間反射による多重閉じ込め現象を,時間分解観測することで,衝突平板壁面の形状と閉じ込めの効率の関係を明らかにし,圧縮性流体のシミュレーションにより閉じ込めが起こる条件での圧力・密度・速度を調べ,閉じ込めに必要な物理条件を明らかにする.その結果に基づいて,壁面-噴流間の反射による多重閉じ込め現象を制御する壁面形状を実際に設計・製作し,表面形状設計の効果を実証する.
|
Outline of Final Research Achievements |
In this study, we obtained design guidelines for the wall surface shape that controls the multiple confinement phenomenon of shock waves, a crucial issue in industry, new energy, and material development. We experimentally demonstrated the design guidelines. In order to clarify the physical conditions necessary for confinement, measurement experiments using a concave-shaped reflector, which is thought to be able to change the physical conditions of the shock wave, revealed experimentally the positional relationship between the convergence position of the shock wave and the jet stream. This indicates that shock waves of various strengths can impinge on the jet, which will be important in the design of future geometries. Furthermore, we found the possibility that the reflection of the shock wave by the jet can be qualitatively organized in terms of acoustic impedance.
|
Academic Significance and Societal Importance of the Research Achievements |
これまで衝撃波が壁面で反射する現象についての基礎的研究は行われてきたが,噴流との反射に関してはほとんど存在なかった.本研究では,噴流と様々な衝撃波を衝突させることで,反射の過程を明らかにした.その結果,噴流および衝撃波が衝突する直前の物理的状態が,衝撃波の反射に大きく影響し,衝撃波および噴流の制御が閉じ込めの指針になることを示した.
|