Kararlı akım koşularında akıma batmamış tekil eğık silindir çevresinde akım ve türbülans yapısı

Due to increase of world population and level of public welfare, an increment need to natural resources and their access methods are observed. Performed tests are indirect endeavors to achieve this purpose. The developed model can be assumed as bridge piers and legs of offshore platforms and offshore wind turbines. The aim of these experiments is to detect the influence of the cylindrical structure with a smooth surface, on separation distance, boundary layer and wake region over the circular cylinder, turbulence and vortex components and their changing manner.All the experiments were conducted in the open channel flow with the size of 18m length, 0.5m width and 0.5m depth. At this case of study four inclined cylinders and upstanding case were studied. Each case contained three discharges (Q1 = 47 lt/s > Q2 =17 lt/s > Q3 =7 lt/s) and the Reynolds number are in the subcritical regime (300< Re< 3×105). Both of Eulerian approach and Lagrangian approach as measuring the flow velocities by one ADV flow velocities were measured and flow visualization were observed by laser sheet The experimental data were analyzed after despiking. Velocity components, turbulence intensities, turbulence kinetic energy and mean kinetic energy were calculated as a non-dimensional parameter. Time average and Reynolds decomposition methods used for derived of three dimensional instantaneous velocity value as mean velocity and fluctuation part of flow velocity. The data are made dimensionless, using the approach undisturbed velocity, Vun, local flow depth, z0, and diameter of cylinder, D. By the results of experimental findings the following facts revealed By the effect of higher Reynolds number the core of separation distance of downstream extended. The magnitude of vertical time-average velocity increased due to the increase of inclination angle. The highest turbulent kinetic energy regions were observed for the vertical cases and by the effect of inclination the turbulent kinetic energy decreases In fact the lower turbulent kinetic energy at the inclination case of cylinder related to more hydrodynamic form as much as vertical case and increasing of submerged volume of cylinder. As result of flow visualization, the highest separation distance at the upstream of cylinder was observed at lowest Reynolds number of vertical case. This means separation was delayed as the influence of higher Reynolds number and separation distance decreased due to increase of inclination.