Tarbiat Modares University Modares Civil Engineering Journal 2476-6763 13 2 2013 04 21 Effects of Bed Roughness on Turbulent Characteristics of a Three-Dimensional Wall Jets Effects of Bed Roughness on Turbulent Characteristics of a Three-Dimensional Wall Jets 95 104 11575 FA A. Shojaeizadeh Tarbiat Modares University M. Ghodsian Tarbiat Modares University A.A. Salehi Neyshaboori Tarbiat Modares University A. Safarzadeh University of Mohaghegh Ardabili Journal Article Abstract: In this paper the experimental study of the flow pattern around a round wall jet has been carried out to investigate the effect of the bed roughness on the turbulence characteristics, including Reynolds stress and turbulence intensities. Measurements were conducted using the three-dimensional velocimeter, ADV and time series of the velocity components are used to investigate the variation of the turbulent flow parameters along the measuring domain. The results showed that by increasing the bed roughness, the streamwise and vertical turbulence intensities increase by downstream distance and for a specific bed roughness the streamwise turbulence intensity is higher than the vertical one. Furthermore, by going downstream from the jet entrance the bed shear stress reduces and by increasing the bed roughness, the bed shear stress has an increasing trend along the jet centerline. Location of the maximum bed shear stress does not change by changing the bed roughness. Abstract: In this paper the experimental study of the flow pattern around a round wall jet has been carried out to investigate the effect of the bed roughness on the turbulence characteristics, including Reynolds stress and turbulence intensities. Measurements were conducted using the three-dimensional velocimeter, ADV and time series of the velocity components are used to investigate the variation of the turbulent flow parameters along the measuring domain. The results showed that by increasing the bed roughness, the streamwise and vertical turbulence intensities increase by downstream distance and for a specific bed roughness the streamwise turbulence intensity is higher than the vertical one. Furthermore, by going downstream from the jet entrance the bed shear stress reduces and by increasing the bed roughness, the bed shear stress has an increasing trend along the jet centerline. Location of the maximum bed shear stress does not change by changing the bed roughness. https://mcej.modares.ac.ir/article_11575_12007262fce809193497e0dd36b00f8d.pdf