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Language: korean

Conflict of Interest: In relation to this article, we declare that there is no conflict of interest.

Publication history: Received April 1, 2003
Accepted October 7, 2003

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기포탑의 압력변동신호의 웨이브렛 변환 해석

Analysis of Pressure Fluctuation Signals in Bubble Column by Wavelet Transform

박성희^† 김상돈¹

Hee Park^† Sang Done Kim¹

우석대학교 화학공학과, 565-701 전북 완주군 삼례읍 후정리 490 ¹한국과학기술원 생명화학공학과, 305-701 대전시 유성구 구성동 373-1

Department of Chemical Engineering, Woosuk University, 490, Hujung-ri, Samnye-eup, Wanju-gun, Chonbuk 565-701, Korea ¹Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701, Korea

drpark@woosuk.ac.kr

Korean Chemical Engineering Research, February 2004, 42(1), 84-88(5), NONE Epub 22 April 2004

Abstract

내부 직경 0.376 m를 갖는 bench scale의 기포탑의 bubbly 흐름 영역과 churn-turbulent 흐름 영역에서 합력 변동 실험을 수행하였다. 이 신호를 해석함에 있어 최근에 개발된 지역 웨이브렛 함수에 기초한 웨이브렛 변환 기법을 이용하였다. 이 때 압력 변동 신호들의 시계열 데이터들은 wavelet decomposition, 이산 웨이브렛 변환 계수, 시간-스케일 표현법으로 해석하였다. 이 웨이브렛 해석기법에 따라 bubbly 흐름영역에서의 요소들은 churn-turbulent 흐름영역에서의 것보다 미세 스케일 특성을 보인다. 따라서 이로부터 웨이브렛 변환기법을 이용하여 기포탑내의 흐름특성의 스케일 성분들을 얻을 수 있다.

Pressure fluctuations experiments were carried out in a bubble column with a moderately large column of 0.376 m ID at different flow regimes such as bubbly and churn-turbulent flow regime. The recently developed technique of wavelet transform based on localized wavelet functions is applicable to analysis of the fluctuating signals. The time series of pressure fluctuation signals have been analyzed by means of coefficients of discrete wavelet transform, wavelet decomposition and timescale representation. By resorting to this technique, the objects in bubbly flow regime have fine scales than ones in churn-turbulent flow regime. Thus, this wavelet transform method enables us to obtain the scale content of local complex flow behaviors in a bubble column.

Keywords

Wavelet Transform Bubble Column Fourier Transform Multiresolution

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