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...

BACKGROUND A noninvasive technique to monitor thermal lesion formation is necessary to ensure the accuracy and safety of high-intensity focused ultrasound (HIFU) treatment. The purpose of this study is to ultrasonically detect the tissue change due to thermal coagulation in the HIFU treatment enhanced by cavitation microbubbles. METHODS An ultrasound imaging probe transmitted plane waves at a...

We have investigated the quantum-to-thermal crossover temperature T for cavitation in liquid helium mixtures up to 5% He concentrations. With respect to the pure He case, T is sizeably reduced, to a value below 50 mK for He concentrations above 2%. As in pure He, the homogeneous cavitation pressure is systematically found close to the spinodal pressure. 64.60.Qb, 64.60.My, 67.60.-g, 67.80.Gb Ty...

The structure and evolution of cavitation in a transparent scaled-up diesel nozzle having a hole inclined at 90, 85, 80 and 0 degree to the nozzle axis has been investigated using high-speed motion pictures, flash photography and stroboscopic visualization. Observations revealed that at the inception stage, cavitation bubbles were not seen at the same locations in all the four nozzles. Cavitati...

In this paper, a new active vision based camera self-calibration technique is proposed. The novelty of this new technique is that it can determine LINEARLY all the FIVE intrinsic parameters of a camera. The basic principle of our new calibration technique is to use the planar information in the scene and to control the camera to undergo several sets of orthogonal planar motions. Then, a set of ...

Self camera calibration based on purely rotational movement of camera receives the most attention among di erent self camera calibration methods due to its algorithmic and operational simplicity. The purely rotational approach, however, assumes camera rotates around its optical center, therefore yielding no translation. This assumption is not realistic since in practice the precise location of ...

Cavitation is an important problem in hydraulic machines that negatively affects their performance and may cause damages. Cavitation is a phenomenon which manifests itself in the pitting of the metallic surfaces of turbine parts because of the formation of cavities. In the present paper, a brief description of the general features of cavitation phenomenon is given and also discussed about the T...