| Popis: |
Publisher Summary This chapter illustrates an experimental method to characterize the vibration amplitude distribution for plane or slightly focused disk transducers. The proof of this method is based on a theoretical calculation that is a combination of three extensions of classical calculations of the field radiated by pistons in terms of impulse-response. The first extension is a derivative formulation of the classical calculations of impulse-responses, which permits an easy physical interpretation. The second permits the calculation of the impulse-response of a transducer having an arbitrary vibration amplitude distribution. The third permits the calculation of the impulse-response in transmit-receive mode after diffraction by a small target. The basic hypotheses are the medium of propagation is fluid—the equation of propagation is the time-dependent linear wave equation. The chapter concludes that the separation of the different echoes is the essential element in the application of the method. The wider the band, the larger the radius of the transducer, and the nearer the target, the easier is application. The alignment of the target must to be as exact as possible. The method can be applied only for transducers that respect the amplitude distribution condition. |
