Electronic edition ISSN 1574-0579

MHD flow in a toroidal duct with a large height-to-width ratio cross-section

Yurong Zhao^1, - Kexin Li^1, - Wenpeng Hong^1, - Jianjun Tao^2, - Yang Yu¹

¹ School of Energy and Power Engineering, Northeast Electric Power University, Jilin 132012, China
² Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China

Abstract
Working conditions and parameters of Boisson's MHD experiment [12] were selected to conduct simulation research, and the flow of conducting incompressible fluids in a toroidal duct with a large height-to-width ratio cross-section was studied. With the working condition of Ha = 7.5894, we explore the flow patterns as the Reynolds number increases, and identify laminar, unstable, and turbulent states. Since experiments are difficult to get information on the entire flow field, the purpose of our analysis was to obtain the velocity distributions of the entire flow field, the critical Reynolds number of instability, and the turbulent information of the flow field. It is found that when the flow is laminar, there are counterclockwise and clockwise flows near the top and bottom cylindrical walls in the meridional plane. When the Reynolds number is slightly higher than 2870, the flow becomes unstable. The vortex first appears near the outer cylindrical wall in the lower middle position of the axial direction. When the Reynolds number reaches 3500, the flow becomes weak and intermittently turbulent. The flows become fully-developed and turbulent when Reynolds numbers are 5000 and 8000. Figs 11, Refs 28.