“…The flow development and transitions dominated by Hartmann braking are not a specific problem in this study, but are common characteristics that influence low-magnetic-Reynolds-number flows confined by walls of electrically insulating materials. Knaepen & Moreau (2008) predicted that MHD damping in the flows confined by walls perpendicular to the magnetic field is not characterized by the interaction parameter N = Q/Re, but by Ha/Re (or N/Ha in a different form; see also Sommeria & Moreau (1982) and Moreau, Thess & Tsinober (2007)). In the present system, Ha/Re is modified to (QPr/Ra) 1/2 as Re ∝ (Ra/Pr) 1/2 .…”