A Pioneering Method for Reducing Water Droplet Erosion

Abstract

Based on computational fluid dynamics and the finite volume method, water droplet erosion in the last stage of an industrial steam turbine was researched and the trajectories of the water droplets were traced by using the Lagrange method. Under steady conditions, the influence of variant bowed vane designs was compared based on the distribution and movement trends of the secondary water droplets. In addition, the effects of the bowed blades on water movement at the vane surfaces and their impact areas and intensity on the blades were analyzed. The results showed that: (1) a negatively bowed blade can reduce the speed of the secondary water droplets at the mid span of the blade, which are also effective for water droplets on the surface of the vanes and (2) a negatively bowed blade improves the speed of the secondary droplets on the end walls of vanes, which is advantageous to the secondary droplets through blade passage and reduction of secondary droplet impulse on the blades.