Aerodynamically compensated static pressure tube

Claim 2

In a pressure-sensing probe, a barrel having first and second ends, strut means at the second end of said barrel to position said barrel spaced from a mounting surface and in position to be impinged by fluid flow, said barrel having a longitudinal axis positioned substantially parallel with respect to normal fluid flow, said barrel having a first outer surface substantially continuously diverging from said longitudinal axis in downstream direction from adjacent the first end of said barrel, and having a second outer surface merged into and joining said first surface and extending downstream therefrom and diverging from the first surface in downstream direction at a greater included angle with respect to said longitudinal axis than said first outer surface, and static pressure-sensing port means opening through said barrel at a preselected position on said first outer surface.

Claim 3

The combination as specified in claim 1 wherein said first and second surfaces are frustoconical surfaces.

Claim 4

The combination as specified in claim 2 wherein sAid second surface forms an angle between 1* and 6* greater with respect to the longitudinal axis of said barrel than the angle formed with said axis by said first surface.

Claim 5

In a static pressure-sensing probe, a short barrel having a longitudinal axis with a first end thereof facing upstream, a support strut attached to said barrel at a second end thereof, said barrel having a first outer surface substantially continuously increasing in cross-sectional size in downstream direction from adjacent the first end of said barrel, and a second outer surface joining said first surface and extending downstream from the first outer surface and increasing in cross-sectional size at a greater included angle with respect to said longitudinal axis of said barrel than said first outer surface, and static pressure port means opening through said barrel in the region of said outer surfaces.

Claim 6

In a static pressure-sensing probe, a short barrel having a longitudinal axis with a first end thereof facing upstream, a support strut attached to said barrel at a second end thereof, said barrel having a first outer surface substantially continuously increasing in cross-sectional size in downstream direction from adjacent the first end of said barrel, and a second outer surface joining said first surface and extending downstream from the first outer surface and increasing in cross-sectional size at a greater included angle with respect to said longitudinal axis of said barrel than said first outer surface, and static pressure port means opening through said barrel in the region of said outer surfaces.

Claim 7

The device of claim 4 wherein at least one of said static pressure-sensing ports opens through said first surface.

Claim 8

The combination as specified in claim 4 wherein first and second outer surfaces are frustoconical.

Claim 9

The combination as specified in claim 4 wherein said first outer surface forms an angle of substantially 2* to 4* with respect to the longitudinal axis of said barrel.

Claim 10

The combination as specified in claim 6 wherein said second outer surface forms an angle with the longitudinal axis of the barrel between 1* and 6* greater than the angle formed by said first outer surface with respect to said longitudinal axis.

Claim 11

The combination as specified in claim 8 wherein at least one of said static pressure-sensing port means is located upstream from the junction between said first and second outer surfaces.

Claim 12

The combination as specified in claim 4 wherein there are two static port means axially displaced along said barrel and said static port means are separately connected to instrumentation to provide dual pressure sensing, said port means being positioned in areas where the pressure sensed at each port means is at a desired relationship to the pressure at the other port means.

Claim 13

In a pressure-sensing probe, a barrel having first and second ends, strut means at the second end of said barrel to positioned said barrel spaced from a mounting surface and in position to be impinged by fluid flow, said barrel having a longitudinal axis positioned substantially parallel with respect to normal fluid flow, said barrel having a substantially frustoconical outer surface substantially continuously diverging from said longitudinal axis in downstream direction from adjacent the first end of said barrel, said probe including a surface irregularity at the downstream terminus of said outer surface which increases the effective size of the probe downstream from the frustoconical outer surface and joined at said frustoconical surface, and static pressure-sensing port means opening through said barrel at a preselected position adjacent said surface irregularity wherein the static pressure is materially influenced by said irregularity at subsonic speed and is influenced by said outer surface at supersonic speed.

Claim 14

In a pressure-sensing probe, a barrel having first and second ends, strut means at the second end of said barrel to positioned said barrel spaced from a mounting surface and in position to be impinged by fluid flow, said barrel having a longitudinal axis positioned substantially parallel with respect to normal fluid flow, said barrel having a substantially frustoconical outer surface substantially continuously diverging from said longitudinal axis in downstream direction from adjacent the first end of said barrel, said probe including a surface irregularity at the downstream terminus of said outer surface which increases the effective size of the probe downstream from the frustoconical outer surface and joined at said frustoconical surface, and static pressure-sensing port means opening through said barrel at a preselected position adjacent said surface irregularity wherein the static pressure is materially influenced by said irregularity at subsonic speed and is influenced by said outer surface at supersonic speed.

Claim 15

The combination as specified in claim 1 1 wherein said first surface forms an angle between 1* and 6* with respect to the longitudinal axis of said barrel.

Claim 16

The pressure-sensing probe of claim 1 wherein said barrel ranges in length between 3 and 12 inches.

Claim 17

The pressure-sensing probe of claim 11 wherein said static pressure port means open through said outer surface.

Claim 18

The static pressure-sensing probe of claim 11 wherein said strut means extends asymmetrically from said barrel adjacent one end thereof.

Claim 19

The pressure-sensing probe of claim 11 wherein said barrel is short, and ranges in length between 3 and 12 inches.