Electrohydrodynamic effects on flow redistribution and convective boiling in horizontal concentric tubes under high inlet quality conditions

An experimental investigation was conducted to study the mechanisms of the electrohydrodynamic (EHD) flow boiling in a horizontal concentric flow channel. Experiments were conducted for inlet qualities of 20% to 50%, mass fluxes from 100 kg/m²s to 250 kg/m²s, and applied voltage from 0 kV to 10kV. Time-dependent local surface temperatures along the flow channel, pressure drop, heat flux, inlet and outlet flow regime, and void fractions were measured. An attempt was made to analyze how an electric field may redistribute the two-phase mixture near the heat transfer surface. The results show that the EHD forces may significantly affect heat transfer through the reconstruction of the phase distribution along the length of the heated channel. It is shown that under the parameters investigated, heat flux non-monotonically depends on the length to dryout and two-phase flow patterns as a result of the reorientation of the liquid-vapor contact with the heat transfer surface.