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Journal of Flow Visualization and Image Processing

ISSN for PRINT: 1065-3090

Institutional price:	$586.00
Issues per year:	4

Best Paper Award Selection - Editorial Board Site

2007, Volume14

93 pages

DOI: 10.1615/JFlowVisImageProc.v14.i3

Issue price - $163.00

EFFLUX FROM A COMPOSITE FLOW NETWORK HAVING FLIP-FLOP FLOW IN PARALLEL WITH SLIT FLOWS

Shinzaburo Umeda
Department of Architecture and Civil Engineering, Fukuyama University, Gakuen-cho, Fukuyama, Hiroshima, 729-0292, Japan

Shinji Shigeyama
Graduate Student of Civil and Environmental Engineering, Fukuyama University, Gakuen-cho, Fukuyama, Hiroshima, 729-0292, Japan

Kazuaki Iijima
Technical Research Laboratories, Sanki Engineering Co., LTD, Shimotsuruma, Yamato-Shi, Kanagawa 242-0001, Japan

Chikara Sukehira
Technical Research Laboratories, Sanki Engineering Co., LTD, Shimotsuruma, Yamato-Shi, Kanagawa 242-0001, Japan

Wen-Jei Yang
Department of Mechanical Engineering and Applied Mechanics, University of Michigan, Ann Arbor, Michigan 48109, U.S.A.

ABSTRACT

An experimental study is performed on a composite flow network consisting of a diamond-shaped cylinder bundle sandwiched between two slit flows. Air serves as the working fluid. An YAG laser is used as a light source for illumination. A PIV measurement technique is employed to visualize flow phenomena which are recorded by means of a CCD camera. The cylinder bundle is made of transparent acrylic material and two sets of slit flows of different size are fabricated. For comparison, a traditional flow channel of rectangular cross section and a composite flow network with a diamond-shaped cylinder bundle in parallel with a slit flow on one side are tested. Both velocity vector and vorticity distributions in the efflux region are obtained to determine the flow patterns. It is disclosed that the flip-flop flow generated inside the cylinder bundle assists the slit flows to stretch through suppressing the diffusing phenomenon of the efflux jet stream. The mechanisms for the stable efflux stretching are determined. The study can have an important application to the development of stable fluid films such as air curtains for environmental purification and protection.