Abstract
The effects of periodic perturbation on turbulent separated flow in a two-dimensional asymmetric diffuser were investigated. Measurements of velocity fields were undertaken using a LDV, and data reduction was conducted on a time-averaged as well as ensemble-averaged manner that made the mean-periodic-turbulent decomposition possible. Effects of imposed perturbation on the velocity field strongly depend on the frequency of the perturbation, and the optimum frequency ranges between 0.01≤St≤0.04, with St being the perturbation frequency normalized by the channel height at the diffuser inlet and the maximum inlet velocity. At the optimum frequency, the effect of perturbation appears as an organized velocity fluctuation along a separated shear flow, resulting in the enhancement of momentum transport, which is the primary effect of imposed perturbation. An increase in the turbulent Reynolds stress component in the recirculation region is also observed, indicating the secondary effect of the organized fluid motion due to periodic perturbation.
| Original language | English |
|---|---|
| Pages (from-to) | 62-68 |
| Number of pages | 7 |
| Journal | Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B |
| Volume | 63 |
| Issue number | 605 |
| Publication status | Published - 1997 Jan |
| Externally published | Yes |
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ASJC Scopus subject areas
- Mechanical Engineering
Cite this
Control of turbulent separated flow in a plane diffuser using periodic perturbation (control effects and response of velocity field). / Ishibashi, Nobumasa; Aoki, Kenta; Obi, Shinnosuke; Masuda, Shigeaki.
In: Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, Vol. 63, No. 605, 01.1997, p. 62-68.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Control of turbulent separated flow in a plane diffuser using periodic perturbation (control effects and response of velocity field)
AU - Ishibashi, Nobumasa
AU - Aoki, Kenta
AU - Obi, Shinnosuke
AU - Masuda, Shigeaki
PY - 1997/1
Y1 - 1997/1
N2 - The effects of periodic perturbation on turbulent separated flow in a two-dimensional asymmetric diffuser were investigated. Measurements of velocity fields were undertaken using a LDV, and data reduction was conducted on a time-averaged as well as ensemble-averaged manner that made the mean-periodic-turbulent decomposition possible. Effects of imposed perturbation on the velocity field strongly depend on the frequency of the perturbation, and the optimum frequency ranges between 0.01≤St≤0.04, with St being the perturbation frequency normalized by the channel height at the diffuser inlet and the maximum inlet velocity. At the optimum frequency, the effect of perturbation appears as an organized velocity fluctuation along a separated shear flow, resulting in the enhancement of momentum transport, which is the primary effect of imposed perturbation. An increase in the turbulent Reynolds stress component in the recirculation region is also observed, indicating the secondary effect of the organized fluid motion due to periodic perturbation.
AB - The effects of periodic perturbation on turbulent separated flow in a two-dimensional asymmetric diffuser were investigated. Measurements of velocity fields were undertaken using a LDV, and data reduction was conducted on a time-averaged as well as ensemble-averaged manner that made the mean-periodic-turbulent decomposition possible. Effects of imposed perturbation on the velocity field strongly depend on the frequency of the perturbation, and the optimum frequency ranges between 0.01≤St≤0.04, with St being the perturbation frequency normalized by the channel height at the diffuser inlet and the maximum inlet velocity. At the optimum frequency, the effect of perturbation appears as an organized velocity fluctuation along a separated shear flow, resulting in the enhancement of momentum transport, which is the primary effect of imposed perturbation. An increase in the turbulent Reynolds stress component in the recirculation region is also observed, indicating the secondary effect of the organized fluid motion due to periodic perturbation.
UR - http://www.scopus.com/inward/record.url?scp=0030673723&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030673723&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0030673723
VL - 63
SP - 62
EP - 68
JO - Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
JF - Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
SN - 0387-5016
IS - 605
ER -