Stepped spillways have been increasingly used to handle flood releases from large dams associated with hydropower plants, and it is important evaluate the fluctuating pressure field on steps. Hydraulic model investigations were conducted three 53° (1V:0.75H) sloping relatively large-stepped chutes characterize mean, fluctuating, extreme pressures acting most critical regions of step faces, near...

To reveal the effect of cavitation on energy conversion characteristics helical axial multiphase pump (Abbreviated to pump), flow in is simulated. The results show that with decrease number ?, firstly extends along streamwise blade suction side, and then turns pressure side blade. When develops fracture stage, completely covered by bubbles; vapor volume fraction impeller almost 0 at inception c...

Cavitation is an essential factor in the deterioration of hydraulic performance centrifugal pumps. The study cavitation fault diagnosis can help avoid or reduce damage it causes. vibration and noise analysis method predict incipient more accurately. In order to improve accuracy diagnosis, this paper studies distribution measuring points for pump diagnosis. research object a with inducer splitte...

Tip vortex cavitation is typically the first type of in real ship propellers due to scale effect. To lessen or eliminate propeller noise, it necessary effectively identify and predict tip initiation run as far possible “non-cavitation area.” However, for current numerical computation, impossible determine minimum pressure at core directly correctly, making difficult anticipate vortex. In this p...

The influence of a bulb runner blade hydrofoil shape on flow characteristics around the was studied. Experimental work performed turbine measuring station and single in cavitating tunnel. In cavitation tunnel, visualization hydrofoil’s suction side. Cavitation structures were observed for several numbers. less intense modified than original hydrofoil, delaying onset by tenths number. results tu...

We analyze the properties of naturally formed nanobubbles in Lennard-Jones molecular dynamics simulations of liquid-to-vapor nucleation in the boiling and the cavitation regimes. The large computational volumes provide a realistic environment at unchanging average temperature and liquid pressure, which allows us to accurately measure properties of bubbles from their inception as stable, critica...

In many cavitating liquid flows, when the number and concentration of the bubbles exceeds some critical level, the flow becomes unsteady and large clouds of cavitating bubbles are periodically formed and then collapse when convected into regions of higher pressure. This phenomenon is known as cloud cavitation and when it occurs it is almost always associated with a substantial increase in the c...