Reduction of Thermodynamic Losses in a Supersonic Nucleating Steam Nozzle by Spraying Water Droplets


Department of Mechanical Engineering,Ferdowsi University of Mashhad


Abstract. During the course of expansion of steam in turbines, the vapour rst supercools and then
nucleates to become a two-phase mixture. Formation of the liquid phase causes thermodynamic and
aerodynamic losses in steam turbines. In this study, the treatment is a one-dimensional, non-equilibrium

ow in a steady Laval nozzle. In this paper, the changes in the rate of nucleation, entropy, pressure and
other parameters of the two-phase
ow, subjected to spraying the liquid droplets close to the nozzle's throat,
are investigated. By injecting the water droplets into a supersonic condensing
ow, the thermodynamic
loss is considerably decreased.