Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 53 Issue 1 (Special Issue) 2021 03 21 Numerical Investigation of Scour Around a Cylindrical Pier in Laboratory Scale Using Euler-Lagrange Approach Numerical Investigation of Scour Around a Cylindrical Pier in Laboratory Scale Using Euler-Lagrange Approach 411 426 3749 10.22060/mej.2019.16679.6418 FA Tina Ebrahimi MSc. Student, Hydraulic structures, Faculty of civil engineering, Babol noshirvani university of technology, Babol, Iran. Mehdi Hamidi Assistant Professor , Hydraulic structures, Faculty of civil engineering, Babol noshirvani university of technology, Babol,Iran. Ali Rahmani Firoozjaiee Assistant Professor, Hydraulic structures, Faculty of civil engineering, Babol noshirvani university of technology, Babol, Iran. Ehsan Khavasi Mechanical engineering department, University of Zanjan Journal Article 2019 07 03 The placement of a pier in flow causes a three-dimensional complex flow pattern around the pier, which leads to a scouring hole around the pier. In this research, modeling of scouring around piers was performed both experimentally and numerically. In the first section of this study, two different scenarios were used to simulate the scouring process. In the two numerical models, the effect of phase coupling and drag models on the scoured bed was investigated. One-way coupling with the sphere drag model was implemented in the first scenario and four-way coupling with a nonsphere drag model in the second one. According to the results, the first model was not satisfying, but the result of the second model was in good agreement with experimental results. The maximum depth of scour at the cross-section in numerical and experimental results was equal (6 percent error). In the second section of this research, in order to study the effect of a collar on the reduction of scouring, a simple cylinder without a collar and then with the presence of a collar at two different levels were performed. The result shows that as the collar goes up, both the maximum depth and the radius of the scour hole increases. The placement of a pier in flow causes a three-dimensional complex flow pattern around the pier, which leads to a scouring hole around the pier. In this research, modeling of scouring around piers was performed both experimentally and numerically. In the first section of this study, two different scenarios were used to simulate the scouring process. In the two numerical models, the effect of phase coupling and drag models on the scoured bed was investigated. One-way coupling with the sphere drag model was implemented in the first scenario and four-way coupling with a nonsphere drag model in the second one. According to the results, the first model was not satisfying, but the result of the second model was in good agreement with experimental results. The maximum depth of scour at the cross-section in numerical and experimental results was equal (6 percent error). In the second section of this research, in order to study the effect of a collar on the reduction of scouring, a simple cylinder without a collar and then with the presence of a collar at two different levels were performed. The result shows that as the collar goes up, both the maximum depth and the radius of the scour hole increases. https://mej.aut.ac.ir/article_3749_2e1751946680c49825aa7caefbd11fb7.pdf