Enrico Corato defends his thesis:

Thermal Considerations in Bulk Acoustic Wave Devices towards Optimised Acoustofluidics

External link to thesis in LUCRIS.

The main goal of my studies was obtaining bulk acoustofluidic devices able to achieve high energy density inside a water-filled cavity. This led us to explore the interplay of sound and thermal effects more in details. Hence, this thesis covers both thermoacoustic effects in Bulk Acoustic Wave devices and a revisited approach for designing them, focusing on achieving good performance. Thermoacoustic effects arise every time an acoustic field interacts with a temperature gradient. Its working mechanism relies on the change in physical properties that heat induces in every substance. By changing the temperature of a fluid, its interaction with sound will also change, hence creating acoustic forces that depend on the temperature distribution. We studied this phenomenon in various configurations, by inducing differential heating either by conduction at the channel boundaries or light absorption within the fluid itself. We employed tracing particles to characterize the resulting thermoacoustic streaming in three-dimensions for each configuration. Comparing our measurements with simulations performed with a finite-element method software, we could probe the limits of our understanding of thermoacoustics.