Topic/Type: 2.1 MHD, EHD & other fluid methods, Poster

Numerical matching scheme for stability analysis of flowing plasmas

J. Shiraishi, S. Tokuda

Japan Atomic Energy Agency

A new numerical scheme for magnetohydrodynamic stability analysis of flowing plasmas is proposed, which is based on the matching theory. If the flow effect is introduced, the historic asymptotic matching scheme should be revisited. The existence of the flow requires the generalization of the Newcomb equation, which describes the marginal state and plays an essential role in the matching scheme. The flow brings about the split of singularity in the generalized Newcomb equation due to the Doppler shift. We point out that the resonant surface can deviate from the singularities if the mode has a real frequency, which indicates that the locations where the resonance occurs cannot be determined a priori. If the mode?s real frequency is limited in certain range, such as the case of the resistive wall mode in laboratory plasmas, the range in which the resonance occurs is finite around the singularity. Hence, the classical asymptotic matching scheme becomes invalid, and a new framework is required. To resolve the difficulty, we propose a new numerical matching scheme, which generalizes the asymptotic one to use the layer with finite width.