서지주요정보
가진된 분류와 분류 확산화염의 혼합 구조에 관한 실험적 연구 = An experimental study on the structure of forced jets and jet diffusion flames
서명 / 저자 가진된 분류와 분류 확산화염의 혼합 구조에 관한 실험적 연구 = An experimental study on the structure of forced jets and jet diffusion flames / 오세기.
저자명 오세기 ; Oh, Sai-Kee
발행사항 [대전 : 한국과학기술원, 1997].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8008144

소장위치/청구기호

학술문화관(문화관) 보존서고

DME 97038

휴대폰 전송

도서상태

이용가능

대출가능

반납예정일

리뷰정보

초록정보

An experimental study was conducted to investigate effects of axial forcing on the flow structures near the nozzle exit in coaxial isothermal jets and jet diffusion flames. The jet was excited by adding a periodic velocity fluctuation ranging from 0 to 400% of the mean jet velocity at a tube resonating frequency. The phase-averaged axial velocity fluctuation at the jet center was measured with one-component LDV and phase-locked visualization using a light chopper and phase conditioning circuit was performed. The changes of large-scale structures in the near field of the jet are described from the visualization of horizontal and vertical cross-cut Mie scattering images. The flow structures of the forced isothermal jet are classified into four regions on the basis of the emergence of azimuthal structures and the periodic behavior of vortex structures. The jittering of azimuthal structures was characterized by the velocity fluctuation ratio and the velocity difference between the jet and the coflowing fluid. The jittering of vortices is found to be related with the vortex pairing and the axial velocity is greatly decreased at this velocity fluctuation ratio. To enhance the mixing by forcing, forcing amplitude should be adjusted to fall in the vortex jittering or break-up region. In case of the forced reacting jet, flame heights were measured from video tape recordings of the sooting images of the flame. The dependence of flame height on the velocity fluctuation ratio shows the existence of a flame length elongation and reduction region. The flame elongation is found to be related to the suppression of the flame flickering by forcing. From the Mie scattering images and flame length measurements, it is suggested that the intense mixing observed in the fully forced laminar jet and the reduction of the flame length is closely related to the development of azimuthal structures.

서지기타정보

서지기타정보
청구기호 {DME 97038
형태사항 vii, 129 p. : 삽도 ; 26 cm
언어 한국어
일반주기 부록 수록
저자명의 영문표기 : Sai-Kee Oh
지도교수의 한글표기 : 신현동
지도교수의 영문표기 : Hyun-Dong Shin
학위논문 학위논문(박사) - 한국과학기술원 : 기계공학과,
서지주기 참고문헌 : p. 111-114
주제 가진 분류
혼합 증진
변동속도비
원주방향 구조
단염화
Forced jet
Mixing enhancement
Velocity fluctuation ratio
Azimuthal structure
Flame length reduction
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