The document discusses different types of nozzles used in steam turbines, including convergent, divergent, and convergent-divergent nozzles. It summarizes thermal modeling and analysis that was conducted to compare the erosion rates of three nozzle types: Moore nozzle, Moses and Stein nozzle, and convergent-divergent nozzle. The analysis found that the convergent-divergent nozzle had the highest velocity and comparatively minimum erosion rate, making it the best performing of the three nozzle types.