LDV measurements and computation of a turbulent circular jet placed non-concentrically in a confining pipe
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I. INTRODUCTION
DESIGN modification and understanding of many industrial processes and environmentally relevant applications require detailed knowledge of turbulent jets. These include transport of pollutants originating from jets into the environment, flow inside combustion chambers, materials processing involving single- and multi-phase jets, etc. Accordingly, a great deal of attention has been focused on studies of turbulent jets in general.[1] One of the most important classes of turbulent jets is the submerged jet, where the fluid leaving a jet is introduced into a body of similar or dissimilar fluid. Specific applications include continuous casting of metals and transport of species and heat in reservoirs. Khodadadi et al.[2] provided a review of literature dealing with studies of submerged jets for which the ratio of the confinement diameter to the jet diameter is not very great, thus distinguishing them from free jet studies. In those studies, a jet that issues fluid into a confining environment is considered. The issuing jets are exclusively circular jets that discharge fluid into a similar fluid confined in a circular pipe or a rectangular box that can be characterized by a hydraulic diameter. A review of those studies is outside the scope of this article, but it suffices to say that few experimental studies have been performed with the jet issuing from the nozzle with a high Reynolds number (i.e., a jet Reynolds number greater than 103). Most of the previous studies have concentrated on jets with very large diameter ratios within symmetric configurations. Consequently, Lan et al.[3] reported, with application to continuous casting of J.M. KHODADADI, Associate Professor, is with the Mechanical Engineering Department, Auburn University, Auburn, AL 36849-5341. B.L. WRIGHT, Systems Engineer, is with Martin Lockheed Management and Data Systems, Springfield, VA 22153. X.K. LAN, R&D Engineer, is with Beloit Corporation, Rockton, IL 61072 Manuscript submitted November 10, 1998. METALLURGICAL AND MATERIALS TRANSACTIONS B
metals in mind, detailed quantitative fluid velocity and turbulence measurements obtained by LDV within a high-Reynolds-number circular jet that is positioned concentrically (or axisymmetrically) in a circular pipe. They also evaluated the predictive capabilities of six k-« turbulence models by comparing the computed velocity and turbulence fields against the measured quantities. Some of these results are summarized together with the results of the present investigation later in the article. As for nonconcentrically positioned (or asymmetric) jet studies, we are aware of only one experimental study of a turbulent jet placed nonconcentrically in a pipe with a secondary fluid stream present (confined jet) and that is the work of Suzuki et al.[4] In that article, attention was placed on measurement of the local wall heat transfer and the effect of eccentricity on the overall heat transfer. No velocity measurements were provided. However, the circumferential and axial variations of the wall heat tr
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