An Investigation of Nucleating Flows of Steam in a Cascade of Turbine Blading

During the course of expansion in turbines steam first supercools and then nucleates to become a wet mixture. To reproduce turbine nucleating conditions realistically requires a supply of supercooled vapor. This can be achieved under blow-down conditions and an experimental facility for such studies has been constructed. The results of the first experimental investigation of nucleating flows of steam in a cascade of nozzle blading using the equipment are presented. The experimental results presented consist of surface pressure measurements, Mach-Zehnder and shadow photography. Comparisons with theoretical solutions show reasonable agreement.