Shear driven film flow behavior and cavitation study

Two complicated important multiphase flow phenomena, shear driven thin film flow and cavitation were studied experimentally. Results were compared with available theoretical models. The main objectives were to study: (1) fluid property effects on shear driven films and interfacial wave structures, and (2) the cavitation flow fields including the effects of long-chain polymer additives (AP-30 and Hec-H) on the cavitation erosion. It is found that: (1) film temperature on the turbine blade surface is equal to the local saturated steam temperature and is independent of water flow rate and water temperature in the reservoir, (2) both high viscosity and long chain polymer additive stabilize the film flow, while low surface tension is destablizing, (3) Mikielewicz's model can be used to predict the transition between rivulet and continous film. (4) Ishii's model can be used to predict transition between continuous film and atomization film flow, (5) Von Karman's universal velocity profile can be used for modelling shear driven film flow.