High-intensity airborne ultrasound

High-intensity airborne ultrasound is used in various technical areas, e.g. for atomizing liquids. High sound pressure levels are required to atomize higher viscosity liquids such as paints or adhesives. In the UltraDis project, among other things, a system for standing wave atomization was set up with which liquids with viscosities of up to approx. 100 Pa s could be atomized. By optimizing the geometry and adjusting the distance between the transducer and reflector, sound pressures of up to 180 dB were achieved. At large vibration amplitudes, the transducer showed an increasingly non-linear behavior, caused on the one hand by the non-linear load and on the other hand by the inherent behavior of the transducer, which made stable operation difficult.

The aim of current research activities on high-intensity airborne ultrasound is to investigate the dynamic oscillation behavior of the ultrasonic transducer under load, to operate it in a controlled manner at the highest possible oscillation amplitude and thus to determine the limits of the atomization process. In this way, a valuable contribution can be made to increasing productivity when atomizing highly viscous liquids.

Publications of the chair on this research topic:

• Modellbasierte und experimentelle Charakterisierung von intensiven Ultraschall-Stehwellenfeldern für die Zerstäubung hochviskoser Flüssigkeiten.
• Atomization of fluids with ultrasound.