### 抄録

A new optical measurement method for local wall shear stress is proposed. The method is an extension of laser Doppler technique. It has a possibility of detecting the both magnitude and angle of local wall shear stress. The principle was investigated for Doppler frequency and measurement volume. The Doppler frequency changes in a Doppler burst signal. The frequency variation depends on the magnitude and angle of local wall shear stress and the spanwise offset of scattering particle path. A signal processing technique is proposed to detect the magnitude and the angle of local wall shear stress. The technique consists of detecting Doppler frequency variation by time-frequency analysis and nonlinear least squares fit. A simulation was conducted to investigate the performance of the method. Simulated Doppler signals were generated by using the instantaneous velocity data of a fluid-flow simulation result. The generated signals with different noise levels were processed and the effect of the noise level was investigated. The local wall shear stress was estimated with moderate accuracy but its angle was not estimated with good accuracy. A further investigation is required to improve the accuracy of measurement for the method.

元の言語 | English |
---|---|

ページ（範囲） | 339-350 |

ページ数 | 12 |

ジャーナル | ICIASF Record, International Congress on Instrumentation in Aerospace Simulation Facilities |

出版物ステータス | Published - 2003 12 1 |

外部発表 | Yes |

イベント | ICIASF '03: 20th International Congress on Instrumentation in Aerospace Simulation Facilities - Gottingen, Germany 継続期間: 2003 8 25 → 2003 8 29 |

### Fingerprint

### ASJC Scopus subject areas

- Aerospace Engineering
- Condensed Matter Physics
- Instrumentation

### これを引用

**A new optical measurement method for local wall shear stress and its signal processing techniques.** / Shirai, Katsuaki.

研究成果: Conference article

}

TY - JOUR

T1 - A new optical measurement method for local wall shear stress and its signal processing techniques

AU - Shirai, Katsuaki

PY - 2003/12/1

Y1 - 2003/12/1

N2 - A new optical measurement method for local wall shear stress is proposed. The method is an extension of laser Doppler technique. It has a possibility of detecting the both magnitude and angle of local wall shear stress. The principle was investigated for Doppler frequency and measurement volume. The Doppler frequency changes in a Doppler burst signal. The frequency variation depends on the magnitude and angle of local wall shear stress and the spanwise offset of scattering particle path. A signal processing technique is proposed to detect the magnitude and the angle of local wall shear stress. The technique consists of detecting Doppler frequency variation by time-frequency analysis and nonlinear least squares fit. A simulation was conducted to investigate the performance of the method. Simulated Doppler signals were generated by using the instantaneous velocity data of a fluid-flow simulation result. The generated signals with different noise levels were processed and the effect of the noise level was investigated. The local wall shear stress was estimated with moderate accuracy but its angle was not estimated with good accuracy. A further investigation is required to improve the accuracy of measurement for the method.

AB - A new optical measurement method for local wall shear stress is proposed. The method is an extension of laser Doppler technique. It has a possibility of detecting the both magnitude and angle of local wall shear stress. The principle was investigated for Doppler frequency and measurement volume. The Doppler frequency changes in a Doppler burst signal. The frequency variation depends on the magnitude and angle of local wall shear stress and the spanwise offset of scattering particle path. A signal processing technique is proposed to detect the magnitude and the angle of local wall shear stress. The technique consists of detecting Doppler frequency variation by time-frequency analysis and nonlinear least squares fit. A simulation was conducted to investigate the performance of the method. Simulated Doppler signals were generated by using the instantaneous velocity data of a fluid-flow simulation result. The generated signals with different noise levels were processed and the effect of the noise level was investigated. The local wall shear stress was estimated with moderate accuracy but its angle was not estimated with good accuracy. A further investigation is required to improve the accuracy of measurement for the method.

UR - http://www.scopus.com/inward/record.url?scp=1642475425&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=1642475425&partnerID=8YFLogxK

M3 - Conference article

AN - SCOPUS:1642475425

SP - 339

EP - 350

JO - ICIASF Record, International Congress on Instrumentation in Aerospace Simulation Facilities

JF - ICIASF Record, International Congress on Instrumentation in Aerospace Simulation Facilities

SN - 0730-2010

ER -