title: Design parameters of stainless steel plates for maximizing high frequency ultrasound wave transmission.
abstract: This work validated, in a higher frequency range, the theoretical predictions made by Boyle around 1930, which state that the optimal transmission of sound pressure through a metal plate occurs when the plate thickness equals a multiple of half the wavelength of the sound wave. Several reactor design parameters influencing the transmission of high frequency ultrasonic waves through a stainless steel plate were examined. The transmission properties of steel plates of various thicknesses (1-7 mm) were studied for frequencies ranging from 400 kHz to 2 MHz and at different distances between plates and transducers. It was shown that transmission of sound pressure through a steel plate showed high dependence of the thickness of the plate to the frequency of the sound wave (thickness ratio). Maximum sound pressure transmission of ∼ 60% of the incident pressure was observed when the ratio of the plate thickness to the applied frequency was a multiple of a half wavelength (2 MHz, 6mm stainless steel plate). In contrast, minimal sound pressure transmission (∼ 10-20%) was measured for thickness ratios that were not a multiple of a half wavelength. Furthermore, the attenuation of the sound pressure in the transmission region was also investigated. As expected, it was confirmed that higher frequencies have more pronounced sound pressure attenuation than lower frequencies. The spatial distribution of the sound pressure transmitted through the plate characterized by sonochemiluminescence measurements using luminol emission, supports the validity of the pressure measurements in this study.
authors: CSIRO Food and Nutrition Flagship, 671 Sneydes Road, Werribee, VIC 3030, Australia; Institute of Biological and Chemical Engineering, University of Erlangen-Nuremberg, Germany.
authors: Mark
authors: M
authors: Michaud
authors: CSIRO Food and Nutrition Flagship, 671 Sneydes Road, Werribee, VIC 3030, Australia; Mechanical and Product Design Engineering, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Australia.
authors: Thomas
authors: T
authors: Leong
authors: CSIRO Food and Nutrition Flagship, 671 Sneydes Road, Werribee, VIC 3030, Australia.
authors: Piotr
authors: P
authors: Swiergon
authors: CSIRO Food and Nutrition Flagship, 671 Sneydes Road, Werribee, VIC 3030, Australia.
authors: Pablo
authors: P
authors: Juliano
authors: CSIRO Food and Nutrition Flagship, 671 Sneydes Road, Werribee, VIC 3030, Australia. Electronic address: kai.knoerzer@csiro.au.
authors: Kai
authors: K
authors: Knoerzer
keywords: Non-contact; Transducer; Transmission; Ultrasound