| Item type |
学術雑誌論文 / Journal Article(1) |
| 公開日 |
2023-08-18 |
| タイトル |
|
|
タイトル |
Helical structures in a temporally developing round jet in the developed state |
|
言語 |
en |
| 言語 |
|
|
言語 |
eng |
| キーワード |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
Temporally developing simulation |
| キーワード |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
Round jet |
| キーワード |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
Koopman decomposition |
| 資源タイプ |
|
|
資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
|
資源タイプ |
journal article |
| 著者 |
Takahashi, Mamoru
Fukui, Ren
Tsujimoto, Koichi
Ando,Toshitake
Shakouchi, Toshihiko
|
| 抄録 |
|
|
内容記述タイプ |
Abstract |
|
内容記述 |
Although existing studies have investigated dominant structures in round jets in developed states, the image of the structures still has been unclear because the observations have often been based on velocity correlation measurements from a limited number of measurement points. In this study we analyzed a full spatiotemporal jet data generated by a largeeddy simulation (LES) to detect the dominant structures of a round jet much more clearly than ever. To save computational resources, we simulated a temporally developing round jet with a jet Reynolds number of 70, 000. Because the temporally developing jet field is homogeneous and periodic in both the streamwise and azimuthal directions, we analyzed the flow field using Koopman decomposition (KD). To analyze the huge numerical data of the jet, the data were reduced using temporal proper orthogonal decomposition (POD), and KD was subsequently performed for the POD modes. In the developed state of the round jet, two layers (inner and outer) are formed. In the inner layer, single-helical structures are formed, and it is confirmed that their streamwise wavelength is in good agreement with those in existing spatially developing round jets (Samie et al., J. Fluid Mech. 916:A2,2021). In the outer layer, we newly find triple-helical structures oriented in the streamwise direction more than the single-helices. Although the energy contained by the triple-helices is smaller than that by the single-helices, they display important contributions to the mean velocity diffusion. Finally, we demonstrate that only five types of helices may approximate the original flow field excellently. |
| 書誌情報 |
Flow, Turbulence and Combustion
巻 111,
p. 59-79
|
| ISSN |
|
|
収録物識別子タイプ |
PISSN |
|
収録物識別子 |
1386-6184 |
| DOI |
|
|
関連タイプ |
isIdenticalTo |
|
|
識別子タイプ |
DOI |
|
|
関連識別子 |
10.1007/s10494-023-00423-4 |
| フォーマット |
|
|
内容記述タイプ |
Other |
|
内容記述 |
application/pdf |
| 著者版フラグ |
|
|
出版タイプ |
VoR |
|
出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |
| 出版者 |
|
|
出版者 |
Springer |
| 資源タイプ（三重大） |
|
|
値 |
Journal Article / 学術雑誌論文 |
2023JA0003.pdf (3.3 MB)
