Author(s)

S. Shabannejad & N. Ashgriz

Abstract

Bubble nucleation in subcooled boiling flow in a horizontal annular channel with a square cross section is investigated. The experiments were performed with water at pressures of between 1 and 2.5 atm and at low heat and mass fluxes. Bubble lift-off diameters were obtained from direct high speed videography. The developed model for the bubble lift-off diameter was obtained by analyzing the forces acting on a bubble and then a model for the bubble growth rate constant was suggested. Our proposed model was then validated by experimental data and it agreed well with the experimental data. The obtained results were also compared with the available correlations from other researchers. Keywords: sub-cooled boiling, forced convection heat transfer, bubble lift-off diameter, flow visualization with high-speed camera, critical heat flux, horizontal annulus, nucleation.

Keywords

sub-cooled boiling, forced convection heat transfer, bubble lift-off diameter, flow visualization with high-speed camera, critical heat flux, horizontal annulus, nucleation.