Characteristics and dynamics of electrolyzed bubbles in magnetohydrodynamic bubbly jet

The magnetohydrodynamics (MHD) are highly relevant to practical applications, including marine propulsion and hydrogen production etc. For better implementation to applications, typical characteristics of the MHD bubbly jet, such as the size distribution and motion of oxygen and hydrogen bubbles, need to be well realized. The MHD bubbly jet generated by high current density associated with strong permanent magnet is experimentally investigated. Two fields of view are taken to analyze the details of micro-sized bubbles and the whole pattern of bubbly jet. To couple the magnetoelectric effects and bubble dynamics, the Reynolds number based on the Lorentz force ReL is applied in the parametric analysis. Dependence of the mean size of bubble on the current density is generally verified. Two regimes regarding the bubble sizes are distinguished. The proposed mechanisms of these two regimes are supported by the pattern of bubbly jet. For ReL≤2000, size of bubble monotonically increases with current density, so that referred to as the electrochemistry regime. Nevertheless, the size of bubble remains nearly unchanged for ReL>2000, referred to as the flow regime in which the turbulent breakup of the bubbly jet core starts to evolve. •Sizes and motions of electrolyzed bubbles in MHD bubbly jet are investigated experimentally.•Two regimes regarding the bubble sizes, referred to as the electrochemistry regime and the flow regime, are categorized.•Sizes of bubbles monotonically increase with current density in the electrochemistry regime.•Bubble size remains nearly unchanged in the flow regime because of turbulent breakup of jet core.