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EP-4741063-A2 - DAMAGE TOLERANT CAVITATION NOZZLE AND METHOD

EP4741063A2EP 4741063 A2EP4741063 A2EP 4741063A2EP-4741063-A2

Abstract

A cavitation nozzle is disclosed, including a plate, a hollow body, and a cap removably engaged with the hollow body and holding the plate against a distal end of the hollow body. The plate may have a central aperture and a distal surface, wherein the distal surface is bisected by a groove and the hollow body is configured to deliver high pressure fluid through the central aperture. The delivered high pressure fluid may be discharged as a cavitating jet.

Inventors

  • DE SILVA, Kandaudage Channa Ruwan
  • SANDERS, DANIEL GORDON
  • SHIMABUKURO, John K.
  • SOYAMA, HITOSHI

Assignees

  • The Boeing Company
  • Tohoku University

Dates

Publication Date
20260513
Application Date
20230525

Claims (15)

  1. A cavitation nozzle (110, 210), comprising: a plate (226) having a central aperture (230) and a distal surface (234), wherein the distal surface is bisected by a groove (262), a hollow body (224) configured to deliver high pressure fluid (114, 220) through the central aperture, and a cap (228) removably engaged with the hollow body, holding the plate against a distal end (236) of the hollow body, wherein the high pressure fluid delivered to the central aperture is discharged as a cavitating jet (222).
  2. The nozzle (110, 210) of claim 1, wherein the plate (226) comprises a diamond crystal material.
  3. The nozzle (110, 210) of either of claims 1 or 2, wherein the plate (226) comprises one or more of the following materials: cubic boron nitride, carbon nitride, boron carbon nitride, metal boride, and nanostructured fullerene.
  4. The nozzle (110, 210) of any preceding claim, wherein the plate (226) comprises one or more of the following materials: cold worked steel, oil hardened steel, air hardened steel, high speed steel, crucible steel, steel with a carbon content between approximately 0.5 and 1.5 percent, chromium-molybdenum steel, and vanadium carbide.
  5. The nozzle (110, 210) of any preceding claim, wherein the distal surface (234) has a frusticonal shape.
  6. The nozzle (110, 210) of any preceding claim, wherein the central aperture (230) of the plate (226) includes a constriction (250) and an expansion (252).
  7. The nozzle (110, 210) of any preceding claim, wherein the distal surface (234) of the plate (226) includes a plurality of recesses (266, 268).
  8. The nozzle (110, 210) of claim 7, wherein the plurality of recesses (266, 268) include a pair of arcuate recesses (266) disposed on opposing sides of the bisecting groove (262).
  9. The nozzle (110, 210) of either of claims 7 and 8, wherein the plurality of recesses (266, 268) include radial linear sections (268), and are symmetric about the bisecting groove (262).
  10. The nozzle (110, 210) of any preceding claim, wherein the cap (228) includes a central channel (238) that receives the plate (226) and the distal end (236) of the hollow body (224).
  11. The nozzle (110, 210) of claim 10, wherein the cap (228) includes a linear slit (282) in fluid communication with the central channel (238), such that the cavitating jet (222) discharged from the central aperture (230) of the plate (226) is discharged through the slit.
  12. The nozzle (110, 210) of claim 11, wherein the slit (282) includes a circular opening (286) concentric with the central channel (238).
  13. The nozzle (110, 210) of any preceding claim, wherein the central aperture (230) of the plate (226) has an elongate cross-sectional shape perpendicular to a direction of fluid flow (246).
  14. A cavitation system (100), comprising: a tank (124) containing a slurry (126, 212) of water (218) and abrasive media (216), a nozzle (110, 210) submerged in the slurry, including: a plate (226) having a central aperture (230) and a distal surface (234), wherein the distal surface is bisected by a groove (262), a hollow body (224) configured to deliver high pressure fluid (114, 220) through the central aperture, and a cap (228) removably engaged with the hollow body, holding the plate against a distal end (236) of the hollow body, wherein the high pressure fluid delivered to the central aperture is discharged into the slurry to form a cloud of cavitation bubbles and energized abrasive particles (146, 254, 280).
  15. A method of cavitation abrasive surface finishing, comprising: immersing (310) a workpiece in a mixture of a liquid and an abrasive, discharging (312) a cavitating jet through a central aperture of a plate of a nozzle, toward a surface of the workpiece, energizing (318) particles of the abrasive with the cavitating jet, directing (322) the energized particles away from the plate of the nozzle with a groove in a distal face of the plate, and removing (324) material from the surface of the workpiece with the energized particles.

Description

BACKGROUND Cavitation Abrasive Surface Finishing (CASF) is a promising new method of mechanically cleaning, smoothing surface roughness, and peening. A cavitating jet is injected into a fluid using a specialized nozzle, and cavitation bubbles are formed in the fluid by a transition to gas phase resulting from an increase in flow velocity and internal energy. The bubbles then collapse as the flow velocity and surrounding pressure dissipates, producing micro-jets that can peen a surface and/or energize abrasive particles that remove material from the surface on impact. However, the energized abrasive particles may also impact the nozzle, quickly causing significant damage. SUMMARY The present disclosure provides systems, apparatus, and methods relating to damage tolerant nozzles for cavitation abrasive surface finishing. In some examples, a cavitation nozzle may include a plate, a hollow body, and a cap removably engaged with the hollow body and holding the plate against a distal end of the hollow body. The plate may have a central aperture and a distal surface, wherein the distal surface is bisected by a groove and the hollow body is configured to deliver high pressure fluid through the central aperture. The delivered high pressure fluid may be discharged as a cavitating jet. In some examples, a cavitation nozzle may include a plate, a hollow body, and a cap removably engaged with the hollow body and holding the plate against a distal end of the hollow body. The plate may have a distal face and a central aperture defining a fluid flow axis. The hollow body may be configured to deliver high pressure fluid through the central aperture as a cavitating jet. The cap may have a slit bisecting a distal surface, exposing the central aperture of the plate. In some examples, a cavitation system may include a tank containing a slurry of water and abrasive media, and a nozzle submerged in the slurry. The nozzle may include a plate, a hollow body, and a cap removably engaged with the hollow body and holding the plate against a distal end of the hollow body. The plate may have a central aperture and a distal surface, wherein the distal surface is bisected by a groove and the hollow body is configured to deliver high pressure fluid through the central aperture. The delivered high pressure fluid may be discharged into the slurry to form a cloud of cavitation bubbles and energized abrasive particles. Features, functions, and advantages may be achieved independently in various examples of the present disclosure, or may be combined in yet other examples, further details of which can be seen with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of an illustrative cavitation abrasive surface finishing system including a damage tolerant nozzle in accordance with aspects of the present disclosure.Fig. 2 is a schematic cross-sectional view of another illustrative damage tolerant nozzle submerged in a slurry.Fig. 3 is a schematic cross-sectional view of an illustrative uniform flow nozzle plate.Fig. 4 is a schematic isometric view of another illustrative nozzle plate during cavitation abrasive surface finishing.Fig. 5 is a schematic cross-sectional view of an illustrative frusticonical nozzle plate.Fig. 6 is an isometric view of an illustrative grooved nozzle plate.Fig. 7 is an isometric view of the nozzle plate of Fig. 6 with arcuate recesses.Fig. 8 is an isometric view of the nozzle plate of Fig. 6 with radial recesses.Fig. 9 is an isometric view of the nozzle plate of Fig. 6 with non-uniform radial recesses.Fig. 10 is an isometric view of an illustrative nozzle plate with a diamond insert.Fig. 11 is a schematic diagram of four illustrative opening shapes for a nozzle plate central aperture.Fig. 12 is an isometric view of the nozzle plate and cap of Fig. 2, including a produced cavitation cloud vortex.Fig. 13 is an isometric view of the nozzle plate and cap of Fig. 2, including a projected jet of entrained abrasive media.Fig. 14 is an isometric view of an illustrative wide angle cap.Fig. 15 is a flow chart depicting steps of an illustrative method for reducing nozzle damage during cavitation abrasive surface finishing, according to the present teachings. DETAILED DESCRIPTION Various aspects and examples of a cavitation nozzle configured to tolerate abrasive impact damage, as well as related systems and methods, are described below and illustrated in the associated drawings. Unless otherwise specified, a nozzle in accordance with the present teachings, and/or its various components may, but are not required to, contain at least one of the structures, components, functionalities, and/or variations described, illustrated, and/or incorporated herein. Furthermore, unless specifically excluded, the process steps, structures, components, functionalities, and/or variations described, illustrated, and/or incorporated herein in connection with the present teachings may be i