On the performance of a cascade of turbine rotor tip section blading in wet steam Part 1: Generation of wet steam of prescribed droplet sizes
During the course of expansion in turbines steam nucleates to become a two-phase mixture consisting of a very large number of extremely small droplets carried by the vapour. Turbine stages operating in a two-phase regime have a lower efficiency than those working on superheated steam. To reproduce turbine two-phase flow conditions realistically requires a supply of supercooled steam which can be generated under blow-down conditions by the equipment employed. To generate wet steam the supercooled steam can be passed through a venturi. This paper is one of a set describing an investigation of the performance of a cascade of turbine rotor tip section profiles in wet steam and is concerned with the generation of a supply of wet steam of prescribed droplet sizes for admission to the cascade.