CAVITATION INCEPTION WITNESSED BY SOUND PRESSURE LEVEL IN MODEL TEST AND PROTOTYPE OBSERVATION

The paper concerns with the relationship between cavitation inception and Sound Pressure Level (SPL). A case study for the Xiaolangdi Hydro-project was taken as a typical example, which demonstrated the standard criterion of SPL indicating cavitation inception. Cavitation inception of an orifice plate used for energy dissipation in a tunnel spillway was witnessed and verified both in model test and prototype observation. A design criterion was proposed for a cavitation-free hydraulic structure which can be served as a reference for designers as well as researchers. Consequently, scale effects were discussed with an aim at suggesting an appropriate factor of safety in design.