Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 53 8 2021 10 23 Transverse Flow Characteristics in the Meandering Compound Channels Transverse Flow Characteristics in the Meandering Compound Channels 3499 3516 4253 10.22060/ceej.2021.17983.6728 FA Mohammad Naghavi Ph.D. Candidate in Civil Eng. Water & Hydraulic Structures, Department of Civil Engineering, Faculty of Eng., Urmia University. Mirali Mohammadi Associate Prof. in Civil Eng. Hydraulics & River Mechanics, Dept. of Civil Eng., Faculty of Eng., Urmia University, Urmia, Iran 0000-0001-7194-9393 Ghorban Mahtabi Assistant Professor in Water Engineering, Department of Water Engineering, Faculty of Agriculture, University of Zanjan. Journal Article 2020 02 22 Natural channels always form meanders along their path, and it is important to consider the effect of this meander on the flow characteristics pattern. When a flood occurs, the water level crosses the main section of the river and enters its floodplains. In this case, the river crossing becomes a compound cross-section. In this study, using the Flow3D software (powerful software in the field of computational fluid dynamics),  the vortex rotational power and transverse flow in the meandering compound channel under the influence of relative depth and Sinusoidal Change were investigated. For this purpose, six channels with different sinuosity and three relative depths were used. The results of the numerical simulation showed that the maximum rotational power of vortices increased with an average of about 195% by increasing the sinusoidal rate from 1 to 1.209. The maximum rotational strength of the vortices and the transverse flow rate occurred at a 45-degree angle to the central arc and a sinusoidal value of 1.209. In the main cross-section of the meandering compound channel, for all sinusoidal values, by decreasing the relative depth, the vortex and transverse rotation strengths increased and the rate of change in transverse current power relative to relative depth changes decreased with increasing sinusoidal rate. Natural channels always form meanders along their path, and it is important to consider the effect of this meander on the flow characteristics pattern. When a flood occurs, the water level crosses the main section of the river and enters its floodplains. In this case, the river crossing becomes a compound cross-section. In this study, using the Flow3D software (powerful software in the field of computational fluid dynamics),  the vortex rotational power and transverse flow in the meandering compound channel under the influence of relative depth and Sinusoidal Change were investigated. For this purpose, six channels with different sinuosity and three relative depths were used. The results of the numerical simulation showed that the maximum rotational power of vortices increased with an average of about 195% by increasing the sinusoidal rate from 1 to 1.209. The maximum rotational strength of the vortices and the transverse flow rate occurred at a 45-degree angle to the central arc and a sinusoidal value of 1.209. In the main cross-section of the meandering compound channel, for all sinusoidal values, by decreasing the relative depth, the vortex and transverse rotation strengths increased and the rate of change in transverse current power relative to relative depth changes decreased with increasing sinusoidal rate. https://ceej.aut.ac.ir/article_4253_6a182a16e66268d7ce85fcfe945df787.pdf