Background and Aims: Production of acoustic cavitation by sonication has been recently recommended as a targeted treatment. The experimental results from studies indicate that the activity of cavitation generated by bi- or multi-frequency ultrasound irradiation is higher than that caused by single frequency irradiation. In this study, effects dual (1 MHz and 40 kHz) and single frequency soni...

investigating nozzle’s orifice flow is challenging both experimentally and theoretically. this paper focuses on simulating flow inside diesel injector nozzle via ansys fluent v15. validation is performed with experimental results from winkhofler et al (2001). several important parameters such as mass flow rate, velocity profiles and pressure profiles are used for this validation. results includ...

The objective of the present chapter is to provide the basic concepts and tools required to understand the inception and development of cavitation in liquid flows. The influence of various parameters as the boundary layer and nuclei content is discussed. A special attention is given to thermal effects which may significantly influence the development of cavitation in thermosensitive fluids as c...

The mechanisms involved in traumatic brain injury have yet to be fully characterized. One mechanism that, especially in high-energy trauma, could be of importance is cavitation. Cavitation can be described as a process of vaporization, bubble generation, and bubble implosion as a result of a decrease and subsequent increase in pressure. Cavitation as an injury mechanism is difficult to visualiz...

In this study, the effect of ultrasound irradiation on the flux recovery and fouling mitigation for the membranes made of the polysulfone by the phase inversion method were investigated. Two ultrasound irradiation regimes, including inside and outside the module, were chosen for this study. The experiments were conducted to investigate the effect of ultrasound irradiation on the membrane struct...

Cavitation inception in the near-field of high Reynolds number axisymmetric jets is analyzed using a simplified computational model. The model combines an axisymmetric vorticitystreamfunction finite-difference scheme for the simulation of the unsteady flow field. Using a simplified representation, microscopic bubbles are injected at the jet inlet. The motion of these bubbles is tracked in a Lag...

It is well known that flow instabilities called rotating stall and surge may occur in non-cavitating turbomachines at flow rates smaller than design. Rotating stall is a local instability at the turbomachinery which is basically not dependent on the hydraulic system in which the turbomachine is installed. The stalled region rotates faster than impeller. Surge is a system instability in a hydrau...

Several recent experimental and allalytical investigations of cavitating flows have revealed new phenomena which clearly affect how we should view cavitation growth arid collapse and the strategies used t o ameliorate its adverse effects. On the scale of individual bubbles it is now clear that the dynamics and acoustics of single bubbles are severely affected by the distortion of the bubble by ...

BACKGROUND In aesthetic medicine, the most promising techniques for noninvasive body sculpturing purposes are based on ultrasound-induced fat cavitation. Liporeductive ultrasound devices afford clinically relevant subcutaneous fat pad reduction without significant adverse reactions. This study aims at evaluating the histological and ultrastructural changes induced by ultrasound cavitation on th...