Centre for Industrial Ultrasonics Open Day
25th April 2018
CIU Centre for Industrial Ultrasonics www.ciu.ac.uk 1
Flow Measurement Based on Two-Dimensional
Flexural Ultrasonic Phased Arrays
Lei Kang1 , Andrew Feeney1, and Steve Dixon1&2
Department of Physics1
School of Engineering2
University of Warwick
2CIU Centre for Industrial Ultrasonics www.ciu.ac.uk
Contents
1 Background and motivation
2 Design and optimization
3 Fabrication of flexural ultrasonic arrays
4 Characterization of flexural ultrasonic arrays
5 Flow measurement tests
6 Summary and future research
3CIU Centre for Industrial Ultrasonics www.ciu.ac.uk
Ultrasonic transit-time flow measurement suffers from
beam drift effect which reduces the accuracy and range.
Phased Array technology:
• Adjusting sound beam electronically
and dynamically;
• Measuring through multiple paths
(direct path, reflected paths).
1 Background and Motivation
4CIU Centre for Industrial Ultrasonics www.ciu.ac.uk
1 Background and Motivation
Flexural Ultrasonic Transducers (unimorph, bimorph):
• Uses bending modes in a plate;
• Generates and receives ultrasound
efficiently in fluids;
• Low cost and low voltage supply.
Flexural Ultrasonic Phased Arrays:
• Combining the advantages of flexural
ultrasonic transducers and phased
array technology;
• A potentially economic and low voltage
solution for flow measurement with
higher accuracy and larger range.
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2 Design and Optimization
(0,0) mode (1,0) mode
3D Axisymmetric FE model
(0,0) mode: PZT/Mem=0.92
(1,0) mode: PZT/Mem=0.53
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3 Fabrication
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4 Characterization – impedance analyzer
Table 1: Centre frequency of elements of
a typical array (unit: kHz)
• Backplate not only enhances the
mechanical robustness of the array,
but also improves the performance of
the array in terms of its amplitude,
mode purity, mechanical crosstalk.
• Averaged -6 dB bandwidth: 1.5 kHz.
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8-cycle tone burst signal
transmitting simultaneously
8-cycle tone burst signal
transmitting with time delay
(30o beam steering mode)
Only one element is driven
(study of mechanical cross)
• Array elements vibrate in the (0,0) mode;
• No obvious debonding or weak bonding is observed;
• Crosstalk between neighbouring elements doesn’t severely affect performance.
4 Characterization – laser vibrometer
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5 Flow measurement tests
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5 Flow measurement tests
0 500 1000 1500 2000 2500
Flow rates (m3/h)
470
480
490
500
510
520
530
540
550
560
ToA
s o
f u
ltra
son
ic s
ign
al
(µs)
Tx1 - Rx (17~20)
Tx1 - Rx (21~24)
Tx1 - Rx (25~28)Tx1 - Rx (29~32)
0 500 1000 1500 2000 2500
Flow rates (m3/h)
450
460
470
480
490
500
510
520
ToA
s o
f u
ltra
son
ic s
ign
al
(µs)
Tx1 - Rx (17~20)
Tx1 - Rx (21~24)Rx1 - Tx (17~20)
Rx1 - Tx (21~24)
Rx1 - Tx (25~28)
Rx1 - Tx (29~32)
Upstream
Downstream
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Upstream Downstream
40
38
36
34
32
30
28
26
24
220 500 1000 1500 2000 2500
Flow rates (m3/h)
Ste
erin
g a
ng
le (
o)
Variation of optimum steering angle with flow rates
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5 Flow measurement tests
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5 Flow measurement tests
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6 Summary and Future ResearchSummary
• The design, the fabrication and the characterization of two-dimensional
flexural ultrasonic phased arrays are presented;
• Flow measurements with the arrays are conducted and the results
closely correlate with those measured by a calibrated mechanical flow
meter;
• Flexural ultrasonic phased arrays are a potentially economic and low-
voltage solution for flow measurement with higher accuracy and larger
range.
Future Research
• Compare various data fusion technologies to further improve accuracy;
• Carry out multi-path flow measurement using the 2D phased arrays.
CIU Centre for Industrial Ultrasonics www.ciu.ac.uk
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Flow Measurement based on two-dimensional
Flexural Ultrasonic Phased Array
Thank you for your attention!
Dr. Lei Kang
Research Fellow
Centre for Industrial Ultrasonics
University of Warwick
Email: [email protected]
CIU Centre for Industrial Ultrasonics www.ciu.ac.uk