Experimental characteristics of steam bubble growth at orifices in sub-cooled liquid

The experimentally determined characteristics of steam bubble growth when generated at a number of 1 mm diameter orifices in sub-cooled water are presented. Three orifices were used with a wide range of flowrates and liquid sub-coolings. Tests were conducted at pressures of 2 and 3 bar absolute and at constant flowrate conditions. A high speed cine camera recordings were used to determine the bubble geometrical characteristics such as volume, surface area, and centroid. This data indicated significant dependencies of flowrate, pressure and liquid sub-cooling as would be expected and these have been used to provide non-dimensional correlationʹs for bubble detachment volume and bubble formation time. The effect of neighbouring orifices was investigated by imposing combinations of different orifice flowrates adjacent to the orifice under investigation. The results indicated that the effect of neighbouring orifices is small for the conditions tested.