초록 ▼

A controlled passive porosity system includes a lifting device for operation in a multi-phase liquid, the lifting device having a low pressure surface with a plurality of holes and a high pressure surface with a plurality of holes. A common plenum is disposed within the lifting device and allows flu

A controlled passive porosity system includes a lifting device for operation in a multi-phase liquid, the lifting device having a low pressure surface with a plurality of holes and a high pressure surface with a plurality of holes. A common plenum is disposed within the lifting device and allows fluid communication between liquid adjacent the high pressure surface and liquid adjacent the low pressure surface. When cavitation occurs adjacent to the low pressure surface, a series of valves associated with the holes allows selective and localized fluid communication between the surfaces. The fluid communication has the effect of raising the pressure of the liquid in the area of cavitation, thereby eliminating the cavitation. In an alternate embodiment, the lifting device includes a first plenum, a second plenum, and an intermediate fluid passage, the fluid passage fluidly connecting the first plenum and the second plenum. A valve disposed in the fluid passage selectively blocks or allows fluid communication between the high pressure surface and the low pressure surface to eliminate cavitation.

대표청구항 ▼

1. A lifting device for imparting relative fluid flow in a multi-phase liquid comprising:a leading edge, a trailing edge, a low pressure surface having a first porosity region, and a high pressure surface having a second porosity region, each of the porosity regions comprising a plurality of holes i

1. A lifting device for imparting relative fluid flow in a multi-phase liquid comprising:a leading edge, a trailing edge, a low pressure surface having a first porosity region, and a high pressure surface having a second porosity region, each of the porosity regions comprising a plurality of holes in one of the surfaces; a first plenum located within the lifting device and in communication with the plurality of holes in the first porosity region; a second plenum located within the lifting device and in communication with the plurality of holes in the second porosity region, the second plenum being fluidly connected to the first plenum; and at least one communication passage fluidly connecting the first plenum to the second plenum for allowing fluid flow from the second plenum to the first plenum.