Enhancements for differential-pressure-driven fluid flows

Patent metadata

Field	Value
Publication number	US-9606137-B2
Application number	US-201514742261-A
Country	US
Kind code	B2
Filing date	Jun 17, 2015
Priority date	Jun 17, 2015
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A pitot tube includes a wall that extends longitudinally along an axis. The wall defines an inlet aperture at a longitudinal end of the wall, an outlet aperture opposite the inlet aperture, an interior cavity extending from the inlet aperture to an outlet aperture, a passage extending through and perpendicular to the wall having an outlet along an exterior surface of the wall, and an augmenting feature configured to reduce a static pressure at the outlet of the passage. In another embodiment, a wall defines a passage and an augmenting feature that modifies a flow direction of fluid flowing across an outlet of the passage such that a static pressure of the fluid at the outlet is reduced relative to the wall without the augmenting feature.

First claim

The invention claimed is:

1. A pitot tube comprising:
a wall extending longitudinally along an axis, wherein the wall defines:
an inlet aperture at a longitudinal end of the wall;
an outlet aperture opposite the inlet aperture;
an interior cavity extending from the inlet aperture to an outlet aperture, wherein the inlet aperture places the interior cavity in communication with a space exterior to the wall;
a passage extending through and perpendicular to the wall having an outlet along an exterior surface of the wall; and
an augmenting feature configured to reduce a static pressure at the outlet of the passage.

2. The pitot tube of claim 1 , wherein the augmenting feature is a protrusion having a wedge-shaped longitudinal cross-section.

3. The pitot tube of claim 2 , wherein a radial thickness of the protrusion increases from an upstream end of the protrusion closest to the inlet aperture to a longitudinal location between the upstream end and a central axis of the passage.

4. The pitot tube of claim 3 , wherein a maximum radial thickness of the protrusion is coincident with the central axis of the passage.

5. The pitot tube of claim 2 , wherein the protrusion has a radial thickness defined by a linear profile or a second order polynomial profile.

6. The pitot tube of claim 2 , wherein the protrusion has a length in the longitudinal direction at least 5 times a diameter of the passage, a width transverse to the longitudinal direction at least 3 times the diameter of the passage, and a maximum radial thickness at least 0.25 times the diameter of the passage.

7. The pitot tube of claim 1 , wherein the augmenting feature is a groove extending substantially parallel to the longitudinal direction and intersecting a central axis of the passage, and wherein the groove extends a first length from the passage to an upstream end towards the inlet aperture and a second length from the passage to a downstream end opposite the upstream end.

8. The pitot tube of claim 7 , wherein the first length is different than the second length.

9. The pitot tube of claim 7 , wherein the second length is greater than or equal to the first length.

10. The pitot tube of claim 7 , wherein the groove has a width transverse to the longitudinal direction that is less than or equal to a diameter of the passage.

11. The pitot tube of claim 1 , wherein the augmenting feature is a protrusion having a wedge-shaped longitudinal cross-section in which the protrusion has a groove extending substantially parallel to the longitudinal direction.

12. The pitot tube of claim 11 , where the groove extends from the passage to a surface of the protrusion that extends longitudinally.

13. The pitot tube of claim 11 , wherein the groove has an end face joining a first side face to a second side face, and wherein the end face forms a fillet between the first and second side faces.

14. An apparatus comprising:
a wall extending in a longitudinal direction to partition an interior volume from an exterior space, wherein the wall defines:
a passage extending through and perpendicular to the wall, wherein the passage has an outlet along an exterior surface of the wall; and
an augmenting feature that directs a fluid across the outlet of the passage such that a static pressure of the fluid at the outlet is reduced.

15. The apparatus of claim 14 , wherein the augmenting feature is a protrusion having a wedge-shaped longitudinal cross-section.

16. The apparatus of claim 15 , wherein a radial thickness of the protrusion increases from an upstream end of the protrusion farthest from the passage to a longitudinal location between the upstream end and a central axis of the passage.

17. The apparatus of claim 16 , wherein a maximum radial thickness of the protrusion is coincident with the central axis of the passage.

18. The apparatus of claim 14 , wherein the augmenting feature is a groove extending substantially parallel to the longitudinal direction and intersecting a central axis of the passage, and wherein the groove extends a first length from the passage to an upstream end towards the inlet aperture and a second length from the passage to a downstream end opposite the upstream end.

19. The apparatus of claim 18 , wherein the second length is greater than or equal to the first length.

20. The apparatus of claim 14 , wherein the augmenting feature is a protrusion having a wedge-shaped longitudinal cross-section in which the protrusion has a groove extending substantially parallel to the longitudinal direction.

Assignees

• Rosemount Aerospace Inc

Inventors

• Jacob Robin
• Mahapatra Guru Prasad
• Johnson Paul Robert

Classifications

• G01F1/46

  Pitot tubes · CPC title

• G01P5/165 Primary

  Arrangements or constructions of Pitot tubes · CPC title

• G01K13/028

  for use in total air temperature [TAT] probes · CPC title

• Y02T50/10

  Drag reduction · CPC title