Ultrasonic Flow Meter including a transducer having conical face
An ultrasonic transducer for a pipe includes an ultrasonic source which produces plane waves. The transducer includes a housing having a face at least a portion of which is curved through which the plane waves produced from the source disposed in the housing are emitted and directed outward towards the pipe's interior wall so a full cross-section of the pipe's interior can be measured. A flow meter for detecting fluid flow rates in a pipe. A method for detecting fluid flow rates in a pipe.
1. An ultrasonic transducer for a pipe comprising:
an ultrasonic source which produces plane waves in a fluid flow; and
a housing having a face at least a portion of which is curved through which the plane waves produced from the source disposed in the housing are emitted and directed outward towards the pipe's interior wall so a full cross-section of the fluid flow in the pipe's interior can be measured, wherein a desired angle, φ desired, of the conical shape is defined by:
∅
Desired
=
tan
-
1
[
D
2
-
r
2
L
2
+
sin
∅
face
·
r
z
]
where D is the diameter of the pipe, L is the length of the pipe, r is the radius of the transducer,
sin
∅
face
C
window
=
sin
∅
refract
C
fluid
∅
Desired
=
∅
face
-
∅
refract
.
2. The transducer of claim 1 wherein at least a portion of the face is a portion of a cone.
3. The transducer of claim 2 wherein the face is conically shaped.
4. A flow meter for detecting fluid flow rates in a pipe comprising:
an upstream ultrasonic transducer having a face at least a portion of which is curved in communication with the pipe interior and positioned so plane waves generated by the upstream transducer are directed outward towards the pipe's interior wall and propagate along the pipe's interior so a full cross-section of the fluid flow in the pipe's interior can be measured;
a controller in communication with the upstream transducer which calculates fluid flow rate from the plane waves that have propagated along the pipe's interior; and
a downstream ultrasonic transducer having a face at least a portion of which is curved in communication with the pipe's interior and positioned so plane waves generated by the downstream transducer are directed outward towards the pipe's interior wall ad propagate along the pipe's interior so a full cross-section of the fluid flow in the pipe's interior can be measured and are received by the upstream transducer which produces an upstream transducer signal, the downstream transducer receiving the plane waves from the upstream transducer and providing a downstream transducer signal, the controller in communication with the upstream and downstream transducers which calculates fluid flow rate from the upstream transducer signal and the downstream transducer signal, wherein a desired angle, φ desired, of the conical shape is defined by:
∅
Desired
=
tan
-
1
[
D
2
-
r
2
L
2
+
sin
∅
face
·
r
z
]
where D is the diameter of the pipe, L is the length of the pipe, r is the radius of the transducer,
sin
∅
face
C
window
=
sin
∅
refract
C
fluid
∅
Desired
=
∅
face
-
∅
refract
.
5. The flow meter of claim 4 wherein at least a portion of each face is a portion of a cone.
6. The flow meter of claim 5 wherein each face is conically shaped.
7. The flow meter of claim 6 including a support that extends from the pipe wall into the pipe interior upon which the upstream transducer is mounted.
8. A method for detecting fluid flow rates in a pipe comprising the steps of:
generating plane waves by an upstream transducer having a face at least a portion of which is curved in communication with the pipe interior and positioned so plane waves are directed outward towards the pipe's interior wall and propagate along the pipe's interior so a full cross-section of the fluid flow in the pipe's interior can be measured; and
calculating fluid flow rate from the plane waves that have propagated along the pipe's interior with a controller in communication with the upstream transducer, generating plane waves with a downstream ultrasonic transducer having a face at least a portion of which is curved in communication with the pipe's interior and positioned so the plane waves are directed outward toward the pipe's interior wall and propagate along the pipe's interior so a full cross-section of the fluid flow in the pipe's interior can be measured; receiving the plane waves generated by the downstream transducer at the upstream transducer which produces an upstream transducer signal; receiving the plane waves generated by the upstream transducer at the downstream transducer which produces a downstream transducer signal; providing to the controller in communication with the upstream and downstream transducers the upstream and downstream signals; and calculating with the controller fluid flow rate from the upstream transducer signal and the downstream transducer signal, wherein a desired angle, φ desired, of the conical shape is defined by:
∅
Desired
=
tan
-
1
[
D
2
-
r
2
L
2
+
sin
∅
face
·
r
z
]
where D is the diameter of the pipe, L is the length of the pipe, r is the radius of the transducer,
sin
∅
face
C
window
=
sin
∅
refract
C
fluid
∅
Desired
=
∅
face
-
∅
refract
.
9. The method of claim 8 wherein at least a portion of each face is a portion of a cone.
10. The flow meter of claim 9 wherein each face is conically shaped.