초록

The present invention provides an apparatus and a method for reducing wing-tip vortex energy during seismic exploration. The apparatus includes a vortex concentrator of deployed proximate a tip of a hydrofoil and a vortex reducing device deployed proximate the vortex concentrator.

대표청구항 ▼

What is claimed is: 1. An apparatus, comprising: a marine seismic streamer; a hydrofoil operatively connected to the streamer; a vortex concentrator deployed proximate a tip of the hydrofoil; and a vortex reducing device deployed substantially in the wake of the vortex concentrator thus reducing no

What is claimed is: 1. An apparatus, comprising: a marine seismic streamer; a hydrofoil operatively connected to the streamer; a vortex concentrator deployed proximate a tip of the hydrofoil; and a vortex reducing device deployed substantially in the wake of the vortex concentrator thus reducing noise in sensors contained in the streamer, the vortex reducing device selected from a) a device comprising a hub, a duct and at least one pair of ribs, wherein one of the pair of ribs is coupled to the hub and one of the pair of ribs is coupled to the duct; and b) a propeller. 2. The apparatus of claim 1, wherein the vortex concentrator comprises a rotational body having an axis of cylindrical symmetry. 3. The apparatus of claim 2, wherein the vortex reducing device has an axis of cylindrical symmetry. 4. The apparatus of claim 3, wherein the vortex reducing device is deployed such that the axis of cylindrical symmetry of the vortex reducing device is coaxial with the axis of symmetry of the vortex concentrator. 5. The apparatus of claim 1, wherein the vortex reducing device comprises a hub, a duct, and at least one pair of ribs, and wherein one of the pair of ribs is coupled to the hub and one of the pair of ribs is coupled to the duct. 6. The apparatus of claim 5, wherein each of the ribs has a length that is selected to rectify fluid flowing past the ribs. 7. The apparatus of claim 5, wherein the at least one pair of ribs comprises at least one pair of triangular ribs. 8. The apparatus of claim 5, wherein the at least one pair of ribs comprises eight pairs of triangular ribs. 9. The apparatus of claim 5, wherein a diameter of the duct is selected so that a selected tip vortex velocity is within the duct. 10. The apparatus of claim 5, wherein one of the pair of ribs is deployed on the hub and one of the pair of ribs is deployed on the duct such that each pair of ribs does not substantially shadow another pair of ribs as fluid flows past the pair of ribs, and wherein each rib does not substantially shadow another rib as fluid flows past the pair of ribs. 11. The apparatus of claim 5, wherein at least one of the ribs, the hub, and the duct comprise carbon fiber. 12. The apparatus of claim 1, wherein the vortex reducing device comprises a propeller. 13. The apparatus of claim 12, wherein one or more eigenfrequencies of the propeller are substantially outside a seismic band being sensed by the sensors. 14. The apparatus of claim 12, further comprising a generator, and wherein the propeller is rotationally coupled to the generator so that rotation of the propeller drives the generator. 15. The apparatus of claim 14, wherein the generator is electrically coupled to a battery. 16. The apparatus of claim 14, wherein the generator is electrically coupled to the hydrofoil, and wherein the generator is configured to provide electric power to a control system of the hydrofoil. 17. A method, comprising: towing a marine seismic streamer and a hydrofoil operatively connected to the streamer; concentrating at least one vortex proximate at least one tip of the hydrofoil; and reducing a rotational velocity of the at least one concentrated vortex by passing the concentrated vortex through a vortex reducing device thereby reducing noise in the streamer, the vortex reducing device selected from a) a device comprising a hub, a duct and at least one pair of ribs, wherein one of the pair of ribs is coupled to the hub and one of the pair of ribs is coupled to the duct; and b) a propeller. 18. The method of claim 17, wherein concentrating the at least one vortex proximate the tip of the hydrofoil comprises providing at least one rotational body proximate the tip of the hydrofoil. 19. The method of claim 17, wherein reducing the rotational velocity of the at least one concentrated vortex comprises providing at least one vortex reducing device substantially in a wake of the at least one rotational body. 20. The method of claim 19, wherein providing the at least one vortex reducing device substantially in the wake of the at least one rotational body comprises providing at least one pair of ribs substantially in the wake of the at least one rotational body. 21. The method of claim 20, wherein providing the at least one pair of ribs substantially in the wake of the at least one rotational body comprises providing at least one pair of triangular ribs substantially in the wake of the at least one rotational body. 22. The method of claim 20, wherein providing the at least one pair of ribs substantially in the wake of the at least one rotational body comprises providing the at least one pair of ribs such that each pair of ribs does not substantially shadow another pair of ribs as fluid flows past the pair of ribs, and such that each rib does not substantially shadow another rib as fluid flows past the pair of ribs. 23. The method of claim 16, further comprising generating electrical power using the at least one tip vortex. 24. The method of claim 23, further comprising providing the generated electrical power to at least one of a battery and the hydrofoil. 25. An apparatus, comprising: a marine seismic streamer and a hydrofoil operatively connected to the streamer; a vortex concentrator deployed proximate a tip of the hydrofoil; a hub deployed proximate a trailing end of the vortex concentrator; a duct deployed coaxially with the hub; and at least one pair of ribs, wherein one of the pair of ribs is coupled to the hub and one of the pair of ribs is coupled to the duct. 26. The apparatus of claim 25, where in the at least one pair of ribs comprises a pair of triangular ribs. 27. The apparatus of claim 25, wherein a diameter of the duct is selected so that a selected tip vortex velocity is within the duct. 28. The method of claim 25, wherein at least one of the ribs, the hub, and the duct comprise carbon fiber. 29. An apparatus, comprising: a marine seismic streamer and a hydrofoil operatively connected to the streamer; a vortex concentrator deployed proximate a tip of hydrofoil; and a propeller deployed substantially in the wake of the vortex concentrator such that the propeller acts to reduce a rotational velocity of vortices proximate the tip of the hydrofoil. 30. The apparatus of claim 29, wherein one or more eigenfrequencies of the propeller are substantially outside a seismic band being sensed by sensors in the marine seismic steamer. 31. The apparatus of claim 29, further comprising a generator, and wherein the propeller is rotationally coupled to the generator so that rotation of the propeller drives the generator. 32. The apparatus of claim 31, wherein the generator is electrically coupled to the hydrofoil, and wherein the generator is configured to provide electric power to a control system of the hydrofoil. 33. The apparatus of claim 29, wherein the propeller is designed based upon an expected inflow angle of a fluid flow that includes a linear portion and a highly rotational portion.