Ultrasonic waveguide technique for distribute sensing and measurements of physical and chemical properties of surrounding media

Abstract

This invention relates to a waveguide with distributed sensors that support traveling ultrasonic wave modes to provide quantitative local distributed sensing of the physical and chemical properties of the medium surrounding the sensor locations and/or the material properties of the waveguide. The plurality of sensors is operably associated with a plurality of wave modes for probing and identifying a plurality of properties simultaneously. The reflected waves are representative of local information about the surrounding media at that sensor location.

Claims

1. A method for distributed sensing and measurements of physical and chemical properties of surrounding media, the method comprising: generating at least one ultrasonic wave having a wave mode; providing the at least one ultrasonic wave to a plurality of waveguides, each waveguide has an elongated body configured to guide waves between a first end and a second end to at least one sensor feature of the waveguide between the first end and second end so that each sensor feature reflects a wave mode and/or transmits the wave mode; receive the at least one ultrasonic wave with at least one first receiver transducer that converts the wave mode that traveled along the elongated body into a first electronic signal, wherein each waveguide has a first receiver transducer at the second end thereof that captures the wave mode from the ultrasonic transmitter transducer at the first end of the corresponding waveguide; receiving at least one reflected wave mode with at least one second receiver transducer that converts the reflected wave mode from the elongated body into a second electronic signal, wherein each waveguide has a second receiver transducer at the first end thereof that captures the reflected wave mode that is reflected from the second end of the corresponding waveguide or reflected from the sensor feature of the corresponding waveguide, wherein optionally the at least one ultrasonic transmitter transducer and the at least one second receiver transducer are the same transducer; receiving data into a data collection system from the plurality of first receiver transducers and the plurality of second receiver transducers so as to receive data of the first electronic signal and the second electronic signal; and calculating, with the data collection system, properties of a fluid surrounding the plurality of waveguides.

2. The method of claim 1, wherein each waveguide of the plurality of waveguides is in a form selected from solid rod, wire, plate, sheet, hollow tube, pipe or a shell.

3. The method of claim 1, wherein each waveguide is in a form selected from meandering, circular or a spiral.

4. The method of claim 1, wherein each waveguide has the same ultrasonic transmitter transducer at the respective first end of each waveguide.

5. The method of claim 1, wherein each waveguide has a circular, cylindrical, elliptical, triangular, diamond or a hexagonal cross-section.

6. The method of claim 1, wherein each sensor feature has a form selected from notches, kinks, bends, variable geometry, joints, clamping mechanisms, surface treatments or surface coatings.

7. The method of claim 1, wherein the at least one ultrasonic transmitter transducer and the at least one second receiver transducer are the same transducer at the first end of each waveguide.

8. The method of claim 1, wherein the material of the plurality of waveguides is selected from metals or alloys of metals.

9. The method of claim 1, wherein at least one sensor feature is adapted for partial reflection of the wave mode.

10. The method of claim 1, wherein at least one sensor feature is adapted for full reflection of the wave mode.

11. The method of claim 1, wherein at least one sensor feature is adapted for partial transmission of the wave mode.

12. The method of claim 1, wherein at least one sensor feature is configured to reflect the wave mode into a pulse echo mode.

13. The method of claim 1, wherein at least one sensor feature is configured for partial transmission of the wave mode in a through-transmission mode.

14. The method of claim 1, wherein a spacing arrangement between the plurality of sensor features is uniform.

15. The method of claim 1, wherein a spacing arrangement between the plurality of sensor features is not uniform.

16. The method of claim 1, wherein the wave modes are selected from longitudinal, flexural or torsional modes.

17. The method of claim 1, wherein the wave modes are selected from Longitudinal (L(m,n)), Torsional (T(m,n)), Fiexural (F(m,n)), Anti-Symmetric (A(m)), Symmetric (S(m)) or Shear Horizontal (SH(m)).

18. The method of claim 1, wherein the plurality of ultrasonic transmitter transducers are selected from piezo-electric, electromagnetic, magneto-strictive, thermo-elastic, opto-mechanic al or electro-mechanical.

19. The method of claim 1, wherein the plurality of ultrasonic transmitter transducers are piezo-electric.

20. The method of claim 1, wherein the method is performed with at least a portion of at least one waveguide being in an environment having a temperature range of −100° C. to 2000° C.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1: Typical (some) 2 Dimensional Distributed sensing configurations on an ultrasonic waveguide showing the sensor locations (boxes) and the waveguide (line).

(2) FIG. 2: Typical (some) 3 Dimensional Distributed sensing configurations on an ultrasonic waveguide showing the sensor locations (boxes) and the waveguide (line).

(3) FIG. 3: Typical sensors that can be embodiments on an ultrasonic waveguide in order to provided reflected/transmitted signal signatures. The signature changes are used for sensing the physical and chemical properties of the surrounding media. The use of special coatings that changes its mechanical properties due to exposure to target chemical or physical properties may be combined with other embodiments.

(4) FIG. 4: Typical instrumentation block diagram for the sensor data collection.

(5) FIG. 5: Schematic of some typical wave generation mechanisms using Piezoelectric exciter showing the excitation vibration direction and the wave propagation directions.

(6) FIGS. 6A and 6B: A typical distributed sensor in helical format (FIG. 6A) schematic, (FIG. 6B) as fabricated using metal wire, with 18 notches as reflector embodiment to provide local ultrasonic signatures. This spiral or helical format allows for flexibility in depth/length resolution of the measurements.

(7) FIG. 7: A typical ultrasonic reflected signal signature from the 18 notch spiral or helical waveguide showing the notch reflections and the reflection from the end of the waveguide. The notches here were machined in pairs so that first notch in any pair serves as a reference and difference in the signatures between the first and the second notch is used for measurement.

(8) FIG. 8: The 18 notches helical waveguides experiment results in a uniform region of the furnace, during the heating cycle, with insert of the photo of the sensor inside the uniform region of the furnace. It can be observed that at each time of acquisition of the data, all regions are showing the same temperature. A set of standard thermocouples were used (T-Data) to validate the measurements.

(9) FIG. 9: The validation of the single ultrasonic waveguide distributed sensor in a temperature gradient zone of the furnace (insert) showing that the ultrasonic sensors measurements (U) at different depths are comparable to the standard thermocouple measurements (T) at different time instances of acquisition of data during the heating cycle.

(10) FIG. 10: The schematic representation of multiple waveguides with sensors connected to a single ultrasonic transducer.

THE ADVANTAGES AND UNIQUENESS OF THE INVENTION ARE

(11) Using multiple sensor embodiments on a single waveguide, with the ultrasonic wave interacts with the sensor embodiments to provide a reflected or a transmitted wave, whose signature is assessed to provide local information measurements about the surrounding media in the vicinity of the sensor embodiments.

(12) The wave modes that are generated and received may be of the Longitudinal, Flexural or Torsional modes including, but not limited to, Longitudinal (L(m,n)), Torsional (T(m,n), Flexural (F(m,n)), Anti-Symmetric (A(m)), Symmetric (S(m)), Shear Horizontal (SH(m)), etc. The wave modes used can be mode converted wave modes generated from the sensor embodiments.

(13) The waveguide has configurations, such as linear, meandering, circular, spiral, etc. with the configuration optimized for the type of measurement to be made.

(14) The waveguide configuration and the sensor locations can be in 1 D, 2D or 3D domain.

(15) The waveguide configuration and the sensor locations can be designed to make measurements in a confined volume or over a very large volume through appropriate shape of the waveguide and spacings between the sensor embodiments.

(16) The waveguides may have difference cross-sections including rectangular, circular, cylindrical, elliptical, triangular, diamond, hexagonal, etc. The wave guide may be in the form of a solid rod; wire, plate, sheet, etc., or hollow tube, pipe, shell, etc.

(17) Sensor embodiments may include different forms that provide a local acoustic impedance change. Such embodiments may include notches, dimension changes, bends, Bragg gratings, joints (such as welds), treatments, coatings, etc.

(18) The ultrasonic waveguide gratings could be variable based on the resolution of the (level of fluid and temperature, etc.) measurements due to the radial or axial and or both dimensions.

(19) The sensor embodiments are distributed along the waveguide at distances/spacings that can either be uniform or arbitrary.

(20) The sensor embodiments allow for the partial reflection of the traveling ultrasonic waves at the sensor embodiment locations. This reflected wave and consequently the transmitted wave contains information regarding the local information around the sensor locations.

(21) The reflected and/or transmitted waves are converted into electrical signals and the signature of these signals are analyzed to provide the local information about the surrounding media at each sensor locations.

(22) The local information measurements of the surrounding media that can be measured may include physical properties such as temperature, pressure, viscosity, density, humidity, flow, level, strain, stress, moduli, coefficient of thermal expansion, ultraviolet radiation, magnetic and electric fields, etc., and chemical properties such as chemical composition, concentrations, reactions, cross-linking, etc.

(23) Multiple properties can be simultaneously measured using the same sensor embodiment by using different ultrasonic measurements viz. amplitude, time of flight, frequency, etc.

(24) Multiple properties can be simultaneously measured using the same sensor embodiment by probing using different ultrasonic wave modes.

(25) Multiple properties can be simultaneously measured using the same waveguide Using a combination of the sensor embodiments.

(26) The generation and reception of the waves can be from either one end or generation from one end and reception at the other end or any location on the waveguide.

(27) Generation and Reception of the ultrasonic wave modes may be through appropriate means including piezo-electric, electromagnetic, magnetostrictive, thermo-elastic, opto-mechanical, or electro-mechanical methodologies.

(28) More than one of the wave modes can be generated and received simultaneously to provide multiple signals for measurement.

(29) The analysis can be in time domain, frequency domain, or time-frequency domain.

(30) The waveguide can be made of different materials such as metals, glass, ceramics, polymers, etc.

(31) The distributed sensing can be made from very low temperatures (−100 Celsius) to elevated temperatures (2000 Celsius) by choosing the appropriate material for the waveguide and appropriate sensor embodiment.

(32) The sensor will measure the properties of the inviscid and viscous fluids/Solids/Slurry/etc. in contact with the outside surface or the inside surface of waveguide including viscosity, temperature, or density.

(33) The sensor, when used in multiple numbers, will measure the gradients/profiles of the properties along the length of the waveguide.

(34) The waveguides, when used in multiple numbers, can be connected to a single or plural number of transducers to provide customized monitoring.

(35) The specification includes few embodiments but only for the purpose of understanding. The scope of the invention is not limited by disclosed by these embodiments. All variations and modifications as will be obvious to skilled person is well within the scope and spirit of the invention.