System for focused generation of pressure by bubble formation and collapse
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorJoseph A. Clark
Life of this patent
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Abstract
A pressure generating system uses a shock wave chamber filled with a liquid pressurized to a static pressure different from ambient atmospheric pressure. Once a a preferred location is established in the chamber, a pulsed compressional acoustic shock wave introduced into the liquid is reflected from a free surface of the liquid as a dilatation wave focused on a point at which a bubble forms and expands about an object. The static pressure causes the bubble to collapse around the object to generate a high pressure thereat.
Claims20
In combination with a chamber filled with a liquid having a free surface and a system depositing a predetermined amount of energy for concentration on an object positioned within the chamber, comprising:
- means for pressurizing said liquid to a static pressure different from ambient atmospheric pressure;
- means for introducing an acoustic wave into said liquid;
- and means positioned in the chamber along said free surface of the liquid for reflection and focussing of the acoustic wave onto said object to form a bubble expanding around said object and collapsing in response to said static pressure.
A pressure generating system, comprising:
- a chamber filled with a liquid under ambient atmospheric pressure;
- means for maintaining a free surface within said liquid;
- means for pressurizing said liquid to a static pressure different the ambient atmospheric pressure;
- means for establishing a focus point at a predetermined location in the liquid;
- and
- means for introducing a compressional acoustic shock wave within a predetermined frequency range into said liquid for reflection of a dilatation acoustic shock wave from the free surface to form and expand a bubble at said predetermined location, said static pressure causing collapse of said bubble to establish a predetermined bubble compression ratio.
A method of depositing energy, comprising the steps of:
- providing a chamber with a liquid under ambient atmospheric pressure;
- establishing a preferred location in said liquid;
- pressurizing said liquid through a free surface thereon within the chamber to a static pressure different from the ambient atmospheric pressure;
- and introducing an acoustic wave into said liquid for reflection from said free surface as a dilatation acoustic shock wave focussed on said preferred location to form a bubble thereat in which the energy is concentrated upon collapse of the bubble under said static pressure.
A method of generating pressure, comprising the steps of:
- providing a chamber with a liquid having a free surface;
- locating a point of focus at a predetermined location in said liquid within the chamber at which an object is positioned;
- pressurizing said liquid to a static pressure;
- and introducing an acoustic wave having a predetermined duration into said liquid for reflection from the free surface toward said point of focus to form about said object a bubble collapsing from an expanded state in response to said static pressure to establish a predetermined bubble compression ratio.
In a method of generating high pressure within a small volume by cavitation of a liquid, including the steps of placing said liquid in a chamber under ambient atmospheric pressure and introducing pulsating acoustical energy to induce a cavitation effect within a predetermined zone in the liquid causing formation of a bubble therein, the improvement residing in the steps of:
- pressurizing the liquid within the chamber to a static pressure different from said ambient atmospheric pressure;
- and reflecting from a free surface said acoustical energy within the chamber as a shock wave focused on a point within said predetermined zone in the chamber at which the bubble is formed and collapsed by the static pressure.
Dependencies are inferred from the claim text.