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oai:jaxa.repo.nii.ac.jp:00038270 2023-06-20T22:42:28Z 1887:1891 1896:1898:1913:1915

DNSによる超音速自由せん断流における音波放出機構の研究 A study of sound wave emission mechanism in supersonic free shear flows using DNS 渡辺, 大輔 前川, 博 Watanabe, Daisuke Maekawa, Hiroshi DNS SST 音波 超音速自由せん断流 3次元モデル 音速 ニュートン流体 保存方程式 エネルギー保存 研究開発 圧力分布 Navier-Stokes方程式 DNS SST sound wave supersonic free shear flow 3 dimensional model acoustic velocity Newtonian fluid conservation equation energy conservation research and development pressure distribution Navier-Stokes equation Supersonic free shear flows including near and far fields were calculated by three dimensional direct numerical simulations with shock capturing compact schemes. Mechanism of sound wave emission was investigated in a transitional plane jet. Results from DNS are presented for Mc = 1.17 and Mc = 1.55 plane jets. The previous linear stability analyses showed that the phase velocity of most unstable 3D A1 mode was less than the ambient speed of sound. The result of 2D DNS shows that the amplification of a 2D A1 mode generates strong Mach waves. 3D DNS with A1 oblique modes indicates that the growth of A1 oblique modes have a crucial effect of 3D flow developments and that a less amplification of the 2D A1 mode yields weak Mach waves. These results suggest that quick decreases of the jet centerline velocity caused by the growth of 3D A1 mode restrain the strong Mach wave emission. 資料番号: AA0045948049 レポート番号: NAL SP-57 航空宇宙技術研究所 National Aerospace Laboratory (NAL) 2003-03 jpn conference paper https://jaxa.repo.nii.ac.jp/records/38270 0289-260X AN10097345 航空宇宙技術研究所特別資料: 航空宇宙数値シミュレーション技術シンポジウム2002論文集 Special Publication of National Aerospace Laboratory: Proceedings of Aerospace Numerical Simulation Symposium 2002 57 274 279 https://jaxa.repo.nii.ac.jp/record/38270/files/nalsp0057049.pdf application/pdf 660.8 kB 2020-01-24