Characteristics of confined square jets in the vicinity of a free surface.

Date of Award


Degree Type


Degree Name



Civil and Environmental Engineering


Engineering, Civil.




The results of an experimental investigation of a turbulent jet flow issuing from a square nozzle in the vicinity of a free surface are presented. Experiments were conducted using a two-dimensional laser Doppler anemometer and a particle image velocimeter. The focus of this study was the near region of the jet (X/B < 30). Here, B refers to the nozzle width and X is the distance from the nozzle exit. LDA measurements were conducted at eight stations downstream of the nozzle exit along the centerline of the jet. Four tailwater depths were used in this study. Additional measurements were also conducted to identify axis switching and to this end measurements were obtained at various transverse locations. PIV measurements were conducted in the near jet region (X/B < 3) corresponding to a tailwater depth of 2.5B. A good comprehension of the fluid dynamics of a square jet expanding in the vicinity of the free surface is achieved. Higher order moments were calculated to provide information on the coherent structures and study the role of velocity fluctuations. Two local peaks on either side of the jet centerline is observed. The difference in magnitudes of the peaks indicate differences in the prevailing entrainment characteristics on the top and bottom portions of the jet. Through the quadrant analysis, sweep and ejection type events were observed. To better understand these events, four kinds of eddies are classified for simplicity and their behavior is discussed.* (Abstract shortened by UMI.) *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Microsoft Office.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .S26. Source: Masters Abstracts International, Volume: 44-03, page: 1441. Thesis (M.A.Sc.)--University of Windsor (Canada), 2005.