Ultrasounds in gas media: generation, transmission, applications (review paper)

The focus of this work is on some fundamental issues
concerning ultrasonic wave propagation in gas media. First, a short
characterization of the gas medium and matters related to transmission of
ultrasonic waves in stationary and non-stationary media were presented.
Additionally, the study presents an aeroacoustic range equation which is a basis
of the development of a computer model of an ultrasonic link. Next, attention
turns to matters related to generation of ultrasonic waves in gas media and
problems regarding matching high acoustic impedance of transducers and low
acoustic impedance of gases. Finally, examples of industrial use of ultrasounds
were given and possible future applications in non-contact measurement systems
were suggested.