Method and apparatus for fluid jet formation

An apparatus for generating a high pressure fluid jet for treatment of a selected surface, comprising:

• a source of a first fluid having a pressure of at least approximately 10,000 psi;
• a source of a second fluid;
• a supply conduit coupled to the source of the first fluid;
• a nozzle support body coupled to the supply conduit and having a nozzle passage in fluid communication with the supply conduit;
• a nozzle positioned in the nozzle passage, the nozzle having a nozzle orifice in fluid communication with the source of the first fluid;
• and
• a delivery conduit proximate to the nozzle support body and having a first conduit opening in fluid communication with the nozzle orifice, the delivery conduit further having a second conduit opening spaced apart from the first conduit opening for directing the fluid jet, the delivery conduit having a conduit channel extending between the first and second conduit openings, a length of the conduit channel between the first and second conduit openings being at least approximately ten times a mean diameter of the second conduit opening, at least one of the nozzle and the delivery conduit having at least one aperture coupled to the source of the second fluid, the aperture being between the nozzle orifice and the second opening of the conduit.

An apparatus for controlling a coherence of a high pressure fluid jet used for treating a selected surface, the apparatus comprising:

• a conduit having an opening for supplying a high pressure flow of fluid;
• a nozzle body positioned proximate to the opening of the conduit, the nozzle body having an orifice extending therethrough;
• and
• a turbulence generator positioned at at least one of an upstream and a downstream location relative to the orifice, the turbulence generator being positioned within a selected distance of the orifice to generate turbulence in the high pressure flow of fluid passing adjacent the turbulence generator and control a coherence of the high pressure flow exiting the orifice.

An apparatus for controlling a coherence of a high pressure fluid jet used for treating a selected surface, the apparatus comprising:

• a conduit having an opening for supplying a high pressure flow of fluid;
• a nozzle body positioned proximate to the opening of the conduit, the nozzle body having an orifice extending therethrough;
• and
• turbulence generation means positioned at at least one of an upstream and a downstream location relative to the orifice, the turbulence generation means being positioned within a selected distance of the orifice to generate turbulence in the high pressure flow of fluid passing adjacent the turbulence generation means and control a coherence of the high pressure flow exiting the orifice.