Granted Patent B2

US 12,578,216 · App. 18/505,807 · Granted Mar 17, 2026

Inventors: Jordan Loren Loos (Rockford, IL); Gregory Warren Pulley (Loveland, CO); Brian Lynn Swope (Janesville, WI)

Assignee: Woodward, Inc.

G01F1/668G01F1/662B06B1/0651

Abstract

Claims (152)

1 . A method of sensing, comprising:

activating a first emitter to emit at least a first incident wave in a first direction and emit a second incident wave in a second direction opposite the first direction;

transmitting the first incident wave along a first buffer rod having a first planar axial end abutted to the first emitter and a second planar axial end opposite the first planar axial end;

transmitting the second incident wave along a second buffer rod having a third planar axial end abutted to the first emitter and a fourth planar axial end opposite the third planar axial end;

reflecting a first echo of the first incident wave by a first acoustic reflector defined along a portion of the second planar axial end;

detecting the first echo;

determining a first amplitude of the first echo;

reflecting a second echo of the second incident wave by the fourth planar axial end;

detecting the second echo;

determining a second amplitude of the second echo; and

determining a reflection coefficient based on the first amplitude and the second amplitude.

2 . The method of claim 1 , further comprising determining a fluid acoustic impedance of a fluid at the second planar axial end based on the determined reflection coefficient and a predetermined buffer rod acoustic impedance.

3 . The method of claim 2 , further comprising:

transmitting, at the second planar axial end, a portion of the first incident wave through the fluid to a first sensor arranged a predetermined distance away from and opposite the first emitter, wherein the fluid is within a tubular fluid conduit having a predetermined cross-sectional area;

detecting, by the first sensor, the portion of the first incident wave;

determining, based on the detected portion of the first incident wave, a first time of flight of the portion of the first incident wave;

transmitting, by a second emitter, another first incident wave through the fluid to a second sensor proximal to the first emitter;

detecting, by the second sensor, the other first incident wave; and

determining, based on the detected other first incident wave, a second time of flight of the other first incident wave.

4 . The method of claim 3 , further comprising determining at least one of a velocity of the fluid within the tubular fluid conduit or a speed of sound within the fluid based on the first time of flight, the second time of flight, and the predetermined distance.

5 . The method of claim 4 , further comprising determining a mass fluid flow rate based on the predetermined cross-sectional area, and the determined speed of sound.

6 . The method of claim 5 , wherein the mass fluid flow rate is given by the equation:

m

.

fluid

=

(

V

fluid

C

fluid

)

×

C

d

×

A

×

Z

fluid

=

(

t

up

-

t

dn

t

up

+

t

dn

)

×

C

d

×

A

×

(

Z

buffer

(

1

-

R

)

1

+

R

)

wherein {dot over (m)} fluid is the mass fluid flow rate, V fluid is velocity of the fluid, C fluid is speed of sound in the fluid, C d is a discharge coefficient, A is cross sectional area, Z fluid is acoustic impedance of the fluid, tup is upstream transit time, t dn is downstream transit time, Z buffer is a predetermined buffer rod impedance, and R is a reflection coefficient.

7 . The method of claim 3 , wherein one or both of the first emitter and the first sensor are piezo elements.

8 . The method of claim 3 , wherein activating the first emitter and detecting, by the first sensor, are performed by a single piezo element.

9 . The method of claim 1 , wherein the first acoustic reflector comprises a matching layer affixed to the fourth planar axial end and having a thickness of (2n−1)λ/4, where n>0 and wherein n is an integer and λ is a wavelength of the first incident wave.

10 . The method of claim 1 , wherein the first planar axial end is abutted to a gas or an at least partial vacuum.

11 . A method of sensing, comprising:

activating a first emitter to emit at least a first incident wave in a first direction and emit a second incident wave in a second direction opposite the first direction;

transmitting the first incident wave along a first buffer rod arranged within a first axial sensor housing portion of an axial interior sensor housing cavity defined by an interior surface of a sensor housing, the first buffer rod comprising a first axial end and a second axial end;

transmitting the second incident wave along a second buffer rod arranged within a second axial sensor housing portion of the axial interior sensor housing cavity, and comprising a third axial end and a fourth axial end, and configured to propagate an incident ultrasonic wave;

reflecting a first echo of the first incident wave by a first acoustic reflector defined along a portion of the second axial end;

detecting the first echo;

determining a first amplitude of the first echo;

reflecting a second echo of the second incident wave by the fourth axial end;

detecting the second echo;

determining a second amplitude of the second echo; and

determining a reflection coefficient based on the first amplitude and the second amplitude.

12 . The method of claim 11 , further comprising determining a fluid acoustic impedance of a fluid at the second axial end based on the determined reflection coefficient and a predetermined buffer rod acoustic impedance.

13 . The method of claim 12 , further comprising:

transmitting, at the second axial end, a portion of the first incident wave through the fluid to a first sensor arranged a predetermined distance away from and opposite the first emitter, wherein the fluid is within a tubular fluid conduit having a predetermined cross-sectional area;

detecting, by the first sensor, the portion of the first incident wave;

determining, based on the detected portion of the first incident wave, a first time of flight of the portion of the first incident wave;

transmitting, by a second emitter, another first incident wave through the fluid to a second sensor proximal to the first emitter;

detecting, by the second sensor, the other first incident wave; and

determining, based on the detected other first incident wave, a second time of flight of the other first incident wave.

14 . The method of claim 13 , further comprising determining at least one of a velocity of the fluid within the tubular fluid conduit or a speed of sound within the fluid based on the first time of flight, the second time of flight, and the predetermined distance.

15 . The method of claim 14 , further comprising determining a mass fluid flow rate based on the predetermined cross-sectional area, and the determined speed of sound.

16 . The method of claim 15 , wherein the mass fluid flow rate is given by the equation:

m

.

fluid

=

(

V

fluid

C

fluid

)

×

C

d

×

A

×

Z

fluid

=

(

t

up

-

t

dn

t

up

+

t

dn

)

×

C

d

×

A

×

(

Z

buffer

(

1

-

R

)

1

+

R

)

wherein {dot over (m)} fluid is the mass fluid flow rate, V fluid is velocity of the fluid, C fluid is speed of sound in the fluid, C d is a discharge coefficient, A is cross sectional area, Z fluid is acoustic impedance of the fluid, tup is upstream transit time, t dn is downstream transit time, Z buffer is a predetermined buffer rod impedance, and R is a reflection coefficient.

17 . The method of claim 13 , wherein one or both of the first emitter and the first sensor are piezo elements.

18 . The method of claim 13 , wherein activating the first emitter and detecting, by the first sensor, are performed by a single piezo element.

19 . The method of claim 11 , wherein the first acoustic reflector comprises a matching layer affixed to the fourth axial end and having a thickness of (2n−1) λ/4, where n>0 and wherein n is an integer and λ is a wavelength of the first incident wave.

20 . The method of claim 11 , wherein the first axial end is abutted to a gas or an at least partial vacuum.

Assignments (1)

Continuity (3)

References Cited (158)