عنوان بررسی تغییرات خطوط جریان در قوس180درجه تند توأم با زوج پایه پل همگرا تحت اثر پارامتر شعاع انحنا با استفاده از نرم افزار ANSYS نوع پژوهش پایان‌نامه کلیدواژه‌ها flow pattern, convergent bridge pier, diagonal piers, vorticity, secondary flow, 180 -degree arc, ANSYS چکیده Bridges are the most common type of attack to rivers, and the creation of passageways and bridges to cross the valleys and rivers is one of the oldest human activities. With the advent of computers, several mathematical models have been solved with simple assumptions of various degrees of precision in order to simulate. The ANSYS software is a very powerful and extensive software for analyzing and simulating complex structures that have been widely considered by users in mechanical engineering, civil engineering, and aerospace engineering, and is highly significant in complementing the valuable laboratory information. Of course, it should be noted that the final results of computer analysis depend on the mathematical model and numerical method. In this research, the design of the flow models around the convergent bridge piers in the river arch is carried out in three dimensions. Here is the ANSYS software that solves flow equations in a finite volume method. For discretization of Navier Stokes equations, the K-? distuR/Bance model was used and for considering the free surface of the fluid volume model. In the construction of the model, a cylindrical piers with a diameter of 5 cm and an oblique angle of 21 ° were used. The bed and walls of the channel were rigid, i.e. without sediment. In this research, the effects of the relative curvature radius of the arc, the position and location of the pier deposition in a 180 degree arc, and the position and positioning of the pier relative to the flow direction on the around flow pattern and around the convergent paired cones were investigated. and was comparison with previous research on the divergent bridge piers. In order to validate the results of numerical modeling, the results of flow velocity measurements were used in an experimental model in an empty arc of 180 °. The most important results of this research are as follows: The maximum secondary flow strength occurred at the base location of the bridge and the maximum پژوهشگران اسماعیل غلام پور (دانشجو)، محمد واقفی (استاد راهنما)، آریا وزیرزاده (استاد راهنما)، سید حامد معراجی (استاد مشاور)