The influence of a continuous sound field on the first oscillation cycle and on the cavitation luminescence of a transient laser-induced bubble is investigated experimentally. The variation of the collapse phase is predicted with a simple numerical model and compared with experiment. Bubble dynamics is mainly influenced by three parameters: the phase of bubble generation, the size of the bubble...

The study investigates the mechanism of ring-liner lubrication in the vicinity of the top and bottom dead centres of an internal combustion engine. Predicting lubricant transient behaviour is critical when the inlet reversal leads to thin films and inherent metal-to-metal interaction. It was found that the cavitation, which is located at the trailing edge of the contact before reversal, briefly...

The optimization of hydrodynamic cavitation as an AOP requires identifying the key parameters and studying their effects on the process. Specific simulations of hydrodynamic bubbles reveal that time scales play a major role on the process. Rarefaction/compression periods generate a number of opposing effects which have demonstrated to be quantitatively different from those found in ultrasonic c...

Abstract: An experimental study is carried out in a cavitation tunnel on a propeller operating downstream of a non-uniform wake. The goal of this work is to establish quantitative correlations between the near pressure field and the cavitation pattern that takes place on the propeller blades. The pressure field is measured at the walls of the test section and in the near wake of the propeller, ...

A recently suggested melt-dispersion mechanism (MDM) for fast reaction of aluminium (Al) nano- and a few micrometre-scale particles during fast heating is reviewed. Volume expansion of 6% during Al melting produces pressure of several GPa in a core and tensile hoop stresses of 10 GPa in an oxide shell. Such stresses cause dynamic fracture and spallation of the shell. After spallation, an unload...

The use of power ultrasound refers to the application of sound that is just above the range of human hearing. Under these conditions, an acoustic wave is able to create very high levels of turbulence within an aqueous solution, through the generation of transient cavitation, the growth and violent collapse of microbubbles. Many scientists will be aware of the use of ultrasonic cell disruptors a...

rF he name of Dr. Charles E. Smith is closely entwined with the modern history of coccidioidomycosis. His early reports1 ’2delineated the endemic area of coccidioidomycosis, the epidemiologic aspects, the life history of the fungus C. immitis, the importance of dust control, the use of coccidioidin, and the development of accurate serologic procedures. He noted that military recruits and travel...

AN INVESTIGATION OF SURFACE RE-FORMATION IN THE PRESENCE OF INERTIAL (TRANSIENT) CAVITATION (GR/N30989/01) P. R. Birkin and T. G. Leighton 1. Background There is an international need to understand the influence of inertial (transient) cavitation on the erosion of surfaces. Electrochemical data, relevant to this area, has been concentrated on the bulk effects observed for relatively large elect...

Roots of hardwoods have been shown to be more vulnerable to xylem cavitation than stems. This study examined whether this pattern is also observed in a conifer species. Vulnerability to cavitation was determined from the pressure required to inject air into the vascular system of hydrated roots and stems, and reduce hydraulic conductance of the xylem. According to the air-seeding hypothesis for...