Evaluation of turbulence models for predicting MHD flows

Seok-Ki Choi¹ - Sun Rock Choi¹ - Hoon-Ki Choi²

¹ Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon, 34057, Korea
² Mechanical Engineering Department, Changwon National University, Changwon, Gyeongsangnamdo, 51140, Korea

Abstract
In the present paper, three different MHD turbulence models are evaluated using experimental data, in order to find out a reliable turbulence model for predicting MHD flows. The Kenjeres and Hanjalic model is very sensitive to the magnetic field magnitude, and the predicted results show that all the predicted Reynolds stresses are completely suppressed when the magnitude of the applied magnetic field becomes large. The Ji and Gardner model and the Murakami and Araseki model result in nearly the same solutions, and the two models adequately predict the axial and vertical Reynolds stresses, but the Reynolds shear stress is under-predicted when the magnitude of the applied magnetic field is large. It is also observed that all three models result in nearly the same solutions when the magnitude of the applied magnetic field is relatively small. In the skin friction coefficient calculations, the three models could not predict the “hump” phenomenon observed in the experiment when the Hartmann number is small. When the Hartmann number is large, all three models predict well the rapidly varying skin friction coefficient. Figs 7, Refs 22.