Ultrasound Transducers for a Simplified Martian Acoustic Anemometer
selection, modeling and verification of ultrasonic transducers in an ultrasound transmit
- receive system are described. The system is applied to the measurement of wind speed
in an acoustic anemometry application. The target environment for the final system is
the surface of Mars, which requires operation in approximately 6 mbar CO2. Four
transducers are tested as part of this ... read morework: Kobitone and PUI piezoelectric transducers,
and custom "CAP1" and capacitive micromachined ultrasound (cMUT) transducers from VN
Instruments and Tufts University, respectively. Tukey - windowed linear chirp acoustic
signal is chosen and analyzed using cross frequency techniques. A model for the full
system frequency response, which includes the control electronics, electromechanical
coupling of the transducers and attenuation of sound, is provided and verified.
Transducers are also characterized using LDV (Laser Doppler Vibrometry) and input
impedance measurement. For PUI transducers, the model provides a peak value within 5% of
the measured value in air and in 6 mbar CO2. Time delay are also predicted to have a
value within 10% difference from the calculated distance in atmospheric air for all the
Thesis (M.S.)--Tufts University, 2018.
Submitted to the Dept. of Mechanical Engineering.
Advisor: Robert White.
Committee: Jason Rife, Brian Tracey, and Don Banfield.
Keyword: Mechanical engineering.read less