Gas probes
A fluid sampling probe is provided. The probe comprises an elongate main tube having: an inlet end, an outlet end, and a fluid-sampling bore disposed within the elongate main tube and extending from the inlet end and to the outlet end; at least three elongate helical fins which are adapted to prevent or reduce probe damage caused by vortex-induced vibration. The elongate helical fins overlap along a length of the elongate main tube; and the fluid-sampling bore is open at or adjacent to the inlet end, and is adapted to receive a fluid-sample extracted from a fluid flowing past the fluid sampling probe. Numerous other aspects are provided.
1. A fluid sampling probe comprising:
an elongate main tube having: an inlet end, an outlet end, and
a fluid-sampling bore disposed within the elongate main tube and extending from the inlet end and to the outlet end;
at least three elongate helical fins which are adapted to prevent or reduce probe damage caused by vortex-induced vibration,
wherein the elongate helical fins overlap along a length of the elongate main tube;
wherein the fluid-sampling bore is open at or adjacent to the inlet end, and is adapted to receive a fluid-sample extracted from a fluid flowing past the fluid sampling probe; and
wherein the elongate helical fins originate adjacent to the inlet end at separate locations.
2. The fluid sampling probe of claim 1 , wherein the elongate main tube is substantially circular in cross-section.
3. The fluid sampling probe of claim 1 , wherein circumferentially-spaced helical flow channels are defined by respective neighboring elongate helical fins.
4. The fluid sampling probe of claim 3 , wherein the elongate helical fins form edges of the associated helical flow channels.
5. The fluid sampling probe of claim 3 , wherein an end of each circumferentially-spaced helical flow channel is substantially flush with the outlet end.
6. The fluid sampling probe of claim 3 , wherein the circumferentially-spaced helical flow channels terminate at or adjacent to the outlet end and at separate locations.
7. The fluid sampling probe of claim 1 , wherein the elongate helical fins have a constant depth which is in the range 0.05 D to 0.5 D, where D is an external diameter or width of the outlet end.
8. The fluid sampling probe of claim 1 , wherein a pitch of each of the plurality of elongate helical fins is in the range D to 20 D, where D is an external diameter or width of the inlet end.
9. The fluid sampling probe of claim 1 , wherein the elongate helical fins overlap each other in an axial direction of the elongate main tube.
10. The fluid sampling probe of claim 1 , wherein a ⅓ or more of a portion of the probe that lies within a flowing fluid has said elongate helical fins.
11. The fluid sampling probe of claim 1 , wherein a number of elongate helical fins is in a range of three to nine.
12. The fluid sampling probe of claim 1 , wherein the elongate helical fins are integrally formed on the elongate main tube.
13. A fluid sampling probe comprising:
an elongate main tube having: an inlet end, an outlet end, and
a fluid-sampling bore disposed within the elongate main tube and extending from the inlet end and to the outlet end;
at least three elongate helical fins which are adapted to prevent or reduce probe damage caused by vortex-induced vibration,
wherein the elongate helical fins overlap along a length of the elongate main tube;
wherein the fluid-sampling bore is open at or adjacent to the inlet end, and is adapted to receive a fluid-sample extracted from a fluid flowing past the fluid sampling probe; and
wherein a ⅓ or more of a portion of the probe that lies within a flowing fluid has said elongate helical fins.