Abstract: Based on the computational fluid dynamics method, simulating the working conditions of hydraulic turbine, the dynamic characteristics of the vapor, liquid and solid phase flow fields (pressure field, velocity field of air bubbles and volume fraction of vapor phase) on the specimen surface is numerically calculated under the interactive erosion and cavitation wears. On the rotating wearing experimental device, the interactive erosion and cavitation wear experiment of three phases is done, and the micro-morphology wear scars on the specimen surface is analyzed. The results show that minimal and maximal pressure values, maximal velocity of air bubbles and maximal volume fractions of vapor phase on the specimen surface all appear on the neighboring region of the cavitation hole by means of numerical analysis, and on the other regions they basically remain unchanged. It is indicated that interactive wears are more severe than single cavitation wears on the neighboring region of the cavitation hole. As far as a certain cavitation hole is concerned, the region of maximal volume fraction of vapor phase expands at a certain angle around the hole edge along rotational direction, and its pressure is minimal or maximal. Through the analysis of the micro-morphology wear scars on the specimen surface, there exist short-range ploughings and cavitation holes, and the wear scars are presented regularity. Simulative air-bubble tracks are in agreement with the wear scars, and the experimental results and theoretical results coincide better, which proves the theoretical analysis is reasonable. The above numerical simulation provides an important basis for revealing the interactive erosion and cavitation wear mechanism of fluid machinery transition parts.

Key words: Erosion and cavitation, Experimental research, Flow field simulation, Interactive wear, Vapor liquid and solid phases