Scholarlink

An estimation of time-resolved (TR) three-dimensional density fields associated with the B mode of the screech tone is performed using non-time-resolved (NTR) multi-camera 3D-BOS and TR microphone measurements. An underexpanded jet at the nozzle pressure ratio of 2.42 is estimated. The first two proper orthogonal decomposition (POD) modes of the \(m=1\) azimuthal Fourier mode for the microphone data are dominant and associated with the B mode. The linear regression model is constructed using these modes and the POD modes of the 3D-BOS data in the \(m=1\) azimuthal Fourier mode. The reconstructed azimuthal structures derived from the leading POD modes of the microphone data exhibit helical modes, with opposite rotation directions. The amplitude of these structures changed with time. Therefore, the azimuthal transition occurs in the B mode.

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Switch of the Azimuthal Structure of an Underexpanded Jet in the Screech B Mode

  • 会议论文

  • 发表日期：

    2025年

查看全文
  • C. Lee,
  • Y. Ozawa,
  • T. Nagata,
  • T. Nonomura

摘要

An estimation of time-resolved (TR) three-dimensional density fields associated with the B mode of the screech tone is performed using non-time-resolved (NTR) multi-camera 3D-BOS and TR microphone measurements. An underexpanded jet at the nozzle pressure ratio of 2.42 is estimated. The first two proper orthogonal decomposition (POD) modes of the \(m=1\) azimuthal Fourier mode for the microphone data are dominant and associated with the B mode. The linear regression model is constructed using these modes and the POD modes of the 3D-BOS data in the \(m=1\) azimuthal Fourier mode. The reconstructed azimuthal structures derived from the leading POD modes of the microphone data exhibit helical modes, with opposite rotation directions. The amplitude of these structures changed with time. Therefore, the azimuthal transition occurs in the B mode.