System and method for thermal inspection of parts

• US 7,651,261 B2
• Filed: 07/10/2007
• Issued: 01/26/2010
• Est. Priority Date: 07/10/2007
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Bunker, Ronald Scott, Allen, Jason Randolph
• Primary Examiner(s): Allen; Andre J
• Application Number:
  US11/775,502
• Publication Number:
  US 20090016402A1
• Time in Patent Office: 931 Days
• Field of Search: 374/107, 374/43
• US Class Current: 374/43
• CPC Class Codes: G01N 25/72 Investigating presence of flaws

Abstract

A method of thermal inspection of a part having at least one internal cavity is provided. The method includes flowing a fluid through the at least one internal cavity. The method also includes measuring a temperature at one or more locations on the part over time. The method further includes calculating at least one of a first and a second derivative of the temperature with respect to time. The method also includes comparing at least one of the first or the second derivative to one or more baseline values to determine if the part meets a desired specification.

Claims

1. A method of thermal inspection of a part having at least one internal cavity, the method comprising:

flowing a fluid through the at least one internal cavity;

measuring a temperature at one or more locations on the part over time;

calculating at least one of a first and a second derivative of the temperature with respect to time; and

comparing at least one of the first or the second derivative to one or more baseline values to determine if the part meets a desired specification.

2. The method of claim 1, further comprising heating or cooling the part prior to performing the flowing step, wherein flowing the fluid provides a steady-flow thermal transient.

3. The method of claim 1, wherein the part is at room temperature prior to performing the flowing step.

4. The method of claim 1, wherein the flowing comprises introducing a steady flow of the fluid.

5. The method of claim 4, wherein the fluid comprises a cooling fluid.

6. The method of claim 4, wherein the fluid comprises a healing fluid.

7. The method of claim 1, wherein the measuring comprises measuring the temperature at the one or more locations on the part via an infrared camera.

8. The method of claim 1, further comprising mapping a thermal profile of the part prior to performing the calculating step.

9. The method of claim 1, wherein the comparing comprises comparing at least one of the first or the second derivative to an upper and a lower specification limit of the part.

10. A system for thermal inspection of a part having at least one internal cavity, the system comprising:

a fluid source configured to provide a flow of a fluid to the part,

a camera configured to capture a plurality of images corresponding to a thermal response of the part to the flow, and

a processor configured to;

calculate at least one of a first and second derivative of a temperature with respect to time; and

compare at least one of the first or the second derivative to one or more baseline values or an acceptable range of values to determine if the part meets a desired specification.

11. The system of claim 10, further comprising a thermal source configured to heat or cool the part.

12. The system of claim 11, wherein the thermal source comprises one of a lamp, an oven, and a fluid.

13. The system of claim 12, wherein the fluid comprises a cooling or a heating fluid.

14. The system of claim 13, wherein the cooling fluid comprises one of air, nitrogen, steam, water, or a Newtonian fluid.

15. The system of claim 13, wherein the heating fluid comprises one of air, nitrogen, steam, water, or a Newtonian fluid.

16. The system of claim 10, wherein the internal cavity is selected from the group consisting of film holes, crossover holes, exit holes, flow channels and combinations thereof.

17. The system of claim 10, further comprising a camera controller configured to control the camera to measure temperature of the part over time.

18. The system of claim 10, wherein the camera comprises an infrared camera.

19. The system of claim 10, wherein the flow of the fluid comprises a steady flow.