Parametric effect of pressure on bubble size distribution in subcooled flow boiling of water in a horizontal annulus

Experiments were performed in subcooled flow boiling of distilled water in horizontal annulus at mass fluxes from 400 to 1200 kg/m2 s, heat fluxes from 0.1 to 1 MW/m2 and pressures varying from 1 to 4 bar at constant subcooling of 20 °C with the intention of studying parametric effect of pressure on bubble size distribution. High speed photography is used to capture bubble images and subsequently processed by National Instruments Labview IMAQ Vision building image processing software. Huge data obtained by automated image processing and analysis algorithms is presented as distribution functions without any spatial and temporal averaging. Bubble size distribution with respect to variation in pressure has been evaluated.