FEEDBACK CONTROL EFFECT IN TURBULENT CHANNEL FLOW WITH A BUMP BY MEANS OF DIRECT NUMERICAL SIMULATION

Yusuke Okochi; Yusuke Nabae; Koji Fukagata

FEEDBACK CONTROL EFFECT IN TURBULENT CHANNEL FLOW WITH A BUMP BY MEANS OF DIRECT NUMERICAL SIMULATION

Yusuke Okochi, Yusuke Nabae, Koji Fukagata

Department of Mechanical Engineering

Research output: Contribution to conference › Paper › peer-review

Abstract

We investigate the effect of feedback control in a turbulent channel flow with a bump by means of direct numerical simulation (DNS). In this study, the opposition control proposed by Choi et al. (1994), which is the simplest feedback control method, is applied and the detection plane is set at about 15 wall units from the wall. Two bulk Reynolds numbers, Re_b = 5600 and 12600, and two different bump heights, h⁺ ≈ 20 and 40, are considered. According to the DNS results, although the pressure drag is hardly changed, the total drag is decreased due to reduction of the friction drag in both cases of h⁺ ≈ 20 and 40. In addition, the control effect decreases as the bump height increases due to enhancement of the flow separation. The control effect decreases also as the Reynolds number increases.

Original language	English
Publication status	Published - 2022
Event	12th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2022 - Osaka, Virtual, Japan Duration: 2022 Jul 19 → 2022 Jul 22

Conference

Conference	12th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2022
Country/Territory	Japan
City	Osaka, Virtual
Period	22/7/19 → 22/7/22

ASJC Scopus subject areas

Aerospace Engineering
Atmospheric Science

Cite this

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title = "FEEDBACK CONTROL EFFECT IN TURBULENT CHANNEL FLOW WITH A BUMP BY MEANS OF DIRECT NUMERICAL SIMULATION",

abstract = "We investigate the effect of feedback control in a turbulent channel flow with a bump by means of direct numerical simulation (DNS). In this study, the opposition control proposed by Choi et al. (1994), which is the simplest feedback control method, is applied and the detection plane is set at about 15 wall units from the wall. Two bulk Reynolds numbers, Reb = 5600 and 12600, and two different bump heights, h+ ≈ 20 and 40, are considered. According to the DNS results, although the pressure drag is hardly changed, the total drag is decreased due to reduction of the friction drag in both cases of h+ ≈ 20 and 40. In addition, the control effect decreases as the bump height increases due to enhancement of the flow separation. The control effect decreases also as the Reynolds number increases.",

author = "Yusuke Okochi and Yusuke Nabae and Koji Fukagata",

note = "Funding Information: Authors are grateful to Drs S. Obi, K. Ando, and T. Kawata (Keio University) for fruitful discussions. This work was supported through JSPS KAKENHI grant No. 18H03758 and 21H05007 by Japan Society for the Promotion of Science. Publisher Copyright: {\textcopyright} 2022 12th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2022. All rights reserved.; 12th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2022 ; Conference date: 19-07-2022 Through 22-07-2022",

year = "2022",

language = "English",

}

TY - CONF

T1 - FEEDBACK CONTROL EFFECT IN TURBULENT CHANNEL FLOW WITH A BUMP BY MEANS OF DIRECT NUMERICAL SIMULATION

AU - Okochi, Yusuke

AU - Nabae, Yusuke

AU - Fukagata, Koji

N1 - Funding Information: Authors are grateful to Drs S. Obi, K. Ando, and T. Kawata (Keio University) for fruitful discussions. This work was supported through JSPS KAKENHI grant No. 18H03758 and 21H05007 by Japan Society for the Promotion of Science. Publisher Copyright: © 2022 12th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2022. All rights reserved.

PY - 2022

Y1 - 2022

N2 - We investigate the effect of feedback control in a turbulent channel flow with a bump by means of direct numerical simulation (DNS). In this study, the opposition control proposed by Choi et al. (1994), which is the simplest feedback control method, is applied and the detection plane is set at about 15 wall units from the wall. Two bulk Reynolds numbers, Reb = 5600 and 12600, and two different bump heights, h+ ≈ 20 and 40, are considered. According to the DNS results, although the pressure drag is hardly changed, the total drag is decreased due to reduction of the friction drag in both cases of h+ ≈ 20 and 40. In addition, the control effect decreases as the bump height increases due to enhancement of the flow separation. The control effect decreases also as the Reynolds number increases.

AB - We investigate the effect of feedback control in a turbulent channel flow with a bump by means of direct numerical simulation (DNS). In this study, the opposition control proposed by Choi et al. (1994), which is the simplest feedback control method, is applied and the detection plane is set at about 15 wall units from the wall. Two bulk Reynolds numbers, Reb = 5600 and 12600, and two different bump heights, h+ ≈ 20 and 40, are considered. According to the DNS results, although the pressure drag is hardly changed, the total drag is decreased due to reduction of the friction drag in both cases of h+ ≈ 20 and 40. In addition, the control effect decreases as the bump height increases due to enhancement of the flow separation. The control effect decreases also as the Reynolds number increases.

UR - http://www.scopus.com/inward/record.url?scp=85143818770&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85143818770&partnerID=8YFLogxK

M3 - Paper

AN - SCOPUS:85143818770

T2 - 12th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2022

Y2 - 19 July 2022 through 22 July 2022

ER -

FEEDBACK CONTROL EFFECT IN TURBULENT CHANNEL FLOW WITH A BUMP BY MEANS OF DIRECT NUMERICAL SIMULATION

Abstract

Conference

ASJC Scopus subject areas

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