Systems and methods for flow measurement

• US 7,274,621 B1
• Filed: 04/23/2003
• Issued: 09/25/2007
• Est. Priority Date: 06/13/2002
• Status: Expired due to Term

• Current Assignee: Raytheon BBN Technlogies Corp. (Rtx Corporation)
• Original Assignee: BBN Technologies (Rtx Corporation)
• Inventors: Coney, William B.
• Primary Examiner(s): Lobo; Ian J.
• Application Number:
  US10/421,065
• Time in Patent Office: 1,616 Days
• Field of Search: 738/611.8, 738/612.1, 731/701.1, 731/701.3, 367/99
• US Class Current: 367/99
• CPC Class Codes: G01F 1/20 by detection of dynamic effects of the flow
• CPC Class Codes: G01F 1/66 by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
• CPC Class Codes: G01P 13/045 with speed indication
• CPC Class Codes: G01P 5/00 Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft application of speed-measuring devices for measuring volume of fluid G01F
• CPC Class Codes: G01P 5/24 by measuring the direct influence of the streaming fluid on the properties of a detecting acoustical wave

Abstract

A system estimates flow parameters associated with a fluid flow encountering a bluff body. The system includes multiple sensors distributed on a surface of a bluff body. The system further includes input circuitry and a sensor processing unit. The input circuitry receives a signal from each of the multiple sensors. The sensor processing unit determines noise levels associated with each of the multiple sensors due to the fluid flow encountering the bluff body. The sensor processing unit further assigns weights to each of the multiple sensors based on the determined noise levels and estimates the fluid flow direction based on the assigned weights.

Claims

1. A method of estimating fluid flow parameters, comprising:

distributing a plurality of sensors over a surface of a body;

determining noise levels associated with each of the plurality of sensors due to a fluid flow encountering the body;

assigning weights to each of the plurality of sensors based on the determined noise levels; and

estimating fluid flow direction based on the assigned weights.

2. The method of claim 1, wherein assigning weights to each of the plurality of sensors further comprises:

assigning large weights to sensors of the plurality of sensors that are subject to high flow noise.

3. The method of claim 1, wherein assigning weights to each of the plurality of sensors further comprises:

assigning small weights to sensors of the plurality of sensors that are subject to low flow noise.

4. The method of claim 1, further comprising:

determining a geometric center of the assigned weights.

5. The method of claim 4, wherein estimating the fluid flow direction is further based on the determined geometric center of the assigned weights.

6. The method of claim 1, wherein the body comprises a three dimensional body.

7. The method of claim 6, wherein the three dimensional body comprises at least one of a sphere, a cylinder, and a cone.

8. The method of claim 1, wherein the determined noise levels comprise root-mean-square (RMS) noise levels.

9. The method of claim 1, wherein the body comprises a sphere and wherein distributing a plurality of sensors over a surface of the body further comprises:

distributing the plurality of sensors around an equator of the sphere.

10. The method of claim 1, wherein the body comprises a sphere and wherein distributing a plurality of sensors over a surface of the body further comprises:

distributing the plurality of sensors at icosahedral points on the sphere.

11. The method of claim 1, wherein the plurality of sensors comprise pressure sensors.

12. The method of claim 1, further comprising:

estimating a velocity of the fluid flow based on at least a portion of the determined noise levels.

13. The method of claim 1, further comprising:

identifying sensors of the plurality of sensors that are located on a downstream face of the body.

14. The method of claim 13, wherein determining noise levels further comprises:

determining noise levels associated with the identified sensors.

15. The method of claim 14, further comprising:

maintaining a look-up table that relates noise levels to fluid flow velocity values.

16. The method of claim 15, wherein estimating the velocity of the fluid flow further comprises:

referencing the look-up table with the determined noise levels associated with the identified sensors to retrieve a corresponding one of the fluid flow velocity values.

17. The method of claim 14, wherein estimating the velocity of the fluid flow further comprises:

calculating the velocity of the fluid flow using the determined noise levels and a function which relates noise levels to fluid flow velocities.

18. A system for estimating flow parameters associated with a fluid flow encountering a bluff body, comprising:

a plurality of sensors distributed on a surface of a bluff body;

input circuitry configured to receive signals from each of the plurality of sensors;

a sensor processing unit configured to;

determine noise levels associated with each of the signals from the plurality of sensors due to the fluid flow encountering the bluff body,

assign weights to each of the plurality of sensors based on the determined noise levels, and

estimate the fluid flow direction based on the assigned weights.

19. The system of claim 18, wherein the sensor processing unit is further configured to:

assign large weights to sensors of the plurality of sensors that are subject to high flow noise.

20. The system of claim 18, wherein the sensor processing unit is further configured to:

assign small weights to sensors of the plurality of sensors that are subject to low flow noise.

21. The system of claim 18, wherein the sensor processing unit is further configured to:

determine a geometric center of the assigned weights.

22. The system of claim 21, wherein the sensor processing unit is further configured to:

estimate the fluid flow direction further based on the determined geometric center of the assigned weights.

23. The system of claim 18, wherein the bluff body comprises a three dimensional body.

24. The system of claim 23, wherein the three dimensional body comprises at least one of a sphere, a cylinder, and a cone.

25. The system of claim 18, wherein the determined noise levels comprise root-mean-square (RMS) noise levels.

26. The system of claim 18, wherein the plurality of sensors comprise pressure sensors.

27. The system of claim 18, wherein the sensor processing unit is further configured to:

estimate a velocity of the fluid flow based on at least a portion of the determined noise levels.

28. The system of claim 18, wherein the sensor processing unit is further configured to:

identify sensors of the plurality of sensors that are located on a downstream face of the bluff body.

29. The system of claim 28, wherein the sensor processing unit is further configured to:

determine noise levels associated with the identified sensors.

30. The system of claim 29, wherein the sensor processing unit is further configured to:

maintain a look-up table that relates noise levels to fluid flow velocity values.

31. The system of claim 30, wherein the sensor processing unit is further configured to:

reference the look-up table with the determined noise levels to retrieve a corresponding one of the fluid flow velocity values.

32. The system of claim 29, wherein the sensor processing unit is further configured to:

calculate the velocity of the fluid flow using the determined noise levels and a function which relates noise levels to fluid flow velocities.

33. A method of estimating fluid flow velocity, comprising:

distributing a plurality of sensors on an external surface of a three dimensional body, wherein the plurality of sensors measure at least one of pressure or force applied to the external surface of the three dimensional body;

determining noise levels associated with the pressure or force measured by at least a portion of the plurality of sensors due to a fluid flowing externally across the external surface of the body; and

estimating a velocity of the fluid flow based on the determined noise levels.

34. The method of claim 33, further comprising:

identifying sensors of the plurality of sensors that are located on a downstream face of the body.

35. The method of claim 34, wherein determining noise levels associated with at least a portion of the plurality of sensors further comprises:

determining noise levels associated with the identified sensors.

36. The method of claim 33, wherein the three dimensional body comprises at least one of a sphere, a cylinder, and a cone.

37. The method of claim 33, further comprising:

maintaining a look-up table that relates noise levels to fluid flow velocity values.

38. The method of claim 37, wherein estimating the velocity of the fluid flow further comprises:

referencing the look-up table with the determined noise levels to retrieve a corresponding one of the fluid flow velocity values.

39. The method of claim 33, wherein estimating the velocity of the fluid flow further comprises:

calculating the velocity of the fluid flow using the determined noise levels and a function which relates noise levels to fluid flow velocities.

48. The method of claim 33, wherein the noise levels comprise root-mean-square (RMS) noise levels.

40. A system for estimating fluid flow velocity, comprising:

a plurality of sensors distributed over a surface of a body;

a sensor processing unit configured to;

maintain a look-up table that relates noise levels to fluid flow velocity values;

determine noise levels associated with at least a portion of the plurality of sensors due to a fluid flow across the surface of the body, and

estimate a velocity of the fluid flow based on the determined noise levels.

41. The system of claim 40, wherein the sensor processing unit is further configured to:

identify sensors of the plurality of sensors that are located on a downstream face of the body.

42. The system of claim 41, wherein the sensor processing unit is further configured to:

determine noise levels of the identified sensors.

43. The system of claim 40, wherein the body comprises a three dimensional body.

44. The system of claim 40, wherein the three dimensional body comprises at least one of a sphere, a cylinder, and a cone.

45. The system of claim 40, wherein the sensor processing unit is further configured to:

calculate the velocity of the fluid flow using the determined noise levels and a function which relates noise levels to fluid flow velocities.

46. The system of claim 40, wherein the plurality of sensors comprise pressure sensors.

47. A system for estimating fluid flow direction, comprising:

a plurality of sensors distributed over a surface of a body;

means for determining noise levels associated with each of the plurality of sensors due to the fluid flow across the surface of the body;

means for assigning weights to each of the plurality of sensors based on the determined noise levels; and

means for estimating the fluid flow direction based on the assigned weights.

49. A method of estimating fluid flow velocity, comprising:

distributing a plurality of sensors over a surface of a body;

determining noise levels associated with at least a portion of the plurality of sensors due to a fluid flow across the surface of the body;

maintaining a look-up table that relates noise levels to fluid flow velocity values; and

estimating a velocity of the fluid flow based on the determined noise levels.

50. The method of claim 49, wherein estimating the velocity of the fluid flow further comprises:

referencing the look-up table with the determined noise levels to retrieve a corresponding one of the fluid flow velocity values.

51. A system for estimating fluid flow velocity, comprising:

a plurality of sensors distributed over a surface of a body;

a sensor processing unit configured to;

maintain a look-up table that relates noise levels to fluid flow velocity values,

determine noise levels associated with at least a portion of the plurality of sensors due to a fluid flow across the surface of the body,

reference the look-up table with the determined noise levels to retrieve a corresponding one of the fluid flow velocity values, and

estimate a velocity of the fluid flow based on the determined noise levels.