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Investigating Performance of Windscop Installed on Towers in Arid Regions with Using Computational Fluid Dynamics (Case Study: I&M Bank in Nairobi) Hooshmand Aini A., Ahmadnia B and Ahmadnia Bh. Journal. Civil Eng. Urban. 4(1): 77-80. 2014 ABSTRACT:The windscops are designed mainly to direct the wind and fresh air in the buildings. The windscops are able to gather the outside air and direct it into the building. If we want to make a windscops very effective, it shall be able to rotate on all directions. The windscops performance reaches to its top point when they are designed to direct the air for a big hall like an amusement park, etc. In this paper we paid more of our focus on performance analysis for a type of windscops which are installed on tower peaks. At first, we conducted analysis by means of GAMBIT software regarding the geometric model of windscops and the structure analysis, and then we continued to analyze them by means of FLUENT software regarding their pattern of flow. The results of such analyses were demonstrated as velocity on X&Y directions, and flow pattern. Keywords:Windscops, Natural Ventilation, CFD, Renewable Energy, FLUENT منبع: [Hidden Content] دانلود: [Hidden Content].,14-12-77-80.pdf J. Civil Eng. Urban.,14-12-77-80.pdf

Numerical Investigation of Length and Thickness of Separation Zone after Sudden Change of Direction in Closed Sections Original Article, B6 Sadeghfam.S, Akhtari.A.A. Journal. Civil Eng. Urban. 2(1): 35-39. 2012. ABSTRACT: Separation phenomenan which is created in result of the inverse pressure gradient reduces the efficiency of the hydraulic systems. Due to eddy flows, analytical solution is not possible. In this paper, the relationship between the length and the thickness of the separation zone versus velocity variations has been investigated by using Fluent, in closed sudden change of direction in square sections with different divergence angles. First, to verify the accuracy of the numerical model, and some other factors such as turbulent model, the results of numerical model have been compared with experimental results in a sudden expansion at several sections. Based on the results of sudden expansion analysis, the turbulence model k-e (RNG) and steady flow mode are used in analysis of two dimensional bends. The results show that for the sharp curvature with central angle of 45 degrees regardless of flow velocity, separation in internal wall doesn't happen. For the sudden change of direction with a central angle of 45 to 90 degrees, flow separation is the function of divergence angles and flow velocity. In this study, the equations in terms of length and thickness of the separation are collected via abundant numerical analysis. Keywords: Separation, Inverse Pressure Gradient, Sudden Change of Direction, Fluent, Turbulent Model k-e (RNG) منبع: [Hidden Content] دانلود: [Hidden Content].,B6-35-39.pdf J. Civil Eng. Urban.,B6-35-39.pdf