Journal of Navigation and Port Research (한국항해항만학회지)

Korean Institute of Navigation and Port Research (한국항해항만학회)
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Flow Field Separating Technique in Bubbly Flow using Discrete Wavelet

이산 웨이블릿을 이용한 Bubbly flow의 유통분리기법

  • Jo, Hyo-Jae (Division of Shipbuilding & Ocean System Engineering, Korea Maritime University) ;
  • Doh, Deog-Hee (Division of Mechanical and Information Engineering, Korea Maritime University) ;
  • Choi, Je-Eun (Department of Mechanical Engineering, Nihon University) ;
  • Takei, Masahiro (Department of Mechanical Engineering, Nihon University) ;
  • Kang, Byung-Yoon (Leading Boat Development)
  • 조효제 (한국해양대학교 조선해양시스템공학부) ;
  • 도덕희 (한국해양대학교 기계정보공학부) ;
  • 최제은 (일본대학교 기계 공학과) ;
  • ;
  • 강병윤 (리딩선박개발)
  • Published : 2008.12.31
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Abstract

Nowadays wavelet transforms are widely used for the analyses of PIV velocity vector fields. This is bemuse the wavelet provides not only spatial information of the velocity vectors but also of time and frequency domains. In this study, a discrete wavelet trC1f1$form has been applied to real PIV images of bubbly flows. The vector fields obtained by a self-made cross-correlation PIV algorithm were used for the discrete wavelet transform The performances of the discrete wavelet transform is investigated by changing the level of power of discretization. The decomposed images by the wavelet multiresolution showed conspicuous characteristics of the bubbly flows according to the level changes. The high spatial bubble concentrated area could be evaluated by the constructed discrete wavelet transform algorithm, at which high leveled wavelets could play a dominant roles to reveal the flow characteristics.

입자영상속도계(PIV)의 해석에 웨이블릿 변환을 적용하여 정성적인 유동정보뿐만 아니라 공간분해능을 갖는 정량적인 속도장 정보를 제공하고 있다 이 기법은 기포유동(bubbly flow)과 같은 다상(multi-phase)의 유동구조를 해석하는 데도 유용하게 살일 수 있다. 본 연구에서는 기체와 액체의 이상유동(two-pase flow)에 PIV기법을 적용하고 이산 웨이블릿 변환을 사용하여 유장해석을 수행함으로써, 기포를 포함한 속도장 특성과 유동특성을 조사한다.

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References

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