| Popis: |
The application of ultrasound to casting process can improve the quality of the casting through the effects of grain refinement, degassing, wetting, deagglomeration and dispersion. For treating large volume of liquid metal, Computational Fluid Dynamics (CFD) study has recently developed an analysis tool capable to model acoustic streaming and cavitation in liquid metal. In general, the cavitation zone is a very small region in fluid, acoustic streaming is main factor for scale-up of ultrasound process because that is a non-linear physical effect which can assist in effective dispersion of cavitation bubble with propagation of the ultrasonic wave in liquid. But previous studies of CFD have limited theoretical model revision to accurately predict cavitation phenomenon. Therefore, this study is focused on the effect of ultrasonic injection conditions and fluid characteristics on acoustic streaming. The acoustic streaming velocity in fluid was measured using Particle Image Velocimetry (PIV) and CFD modeling was performed to predict the acoustic streaming and treatment time in specific volume of fluid by ultrasonic injection. |
