Electronic edition ISSN 1574-0579

Helical magnetorotational instability and turbulence in a Taylor-Couette flow with free-slip top and bottom walls

Y. Zhao¹ , K. Li¹ , W. Hong¹ , J. Tao² , Y. 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
In the paper, we choose the working conditions and parameters of the Potsdam-Rossendorf magnetic instability experiment facility to partly simulate the experiment, but free-slip top and bottom walls are considered. For the working condition of Ha = 7.83 and β = 5.96, we explore the flow pattern, as the Reynolds number increases, and observe laminar, unstable and turbulent states. Since it is hard for the experiment to test information on the entire flow field, our numerical simulation allows us to obtain the velocity distribution of the entire flow field, the critical Reynolds numbers of the unstable state as well as the information on turbulence in the flow field. It is found that instability first occurs near the top wall as the Reynolds number increases. At a low Reynolds number, the axial velocity presents a strip shape near the inner and outer cylindrical walls in the meridional plane. At a high Reynolds number, the strip shape of the axial velocity breaks down and most vorticity concentrates near the inner cylindrical wall. Tables 1, Figs 11, Refs 31.