Purpose: Purpose of this paper is attempt explanation how laser beam processing influence on the cavitation performance of the Fe-Cr-Mn and Fe-Cr-Co alloys. This kind of alloys are frequently used in Polish power plants to routine repairs of damaged blades working under cavitation loading. Design/methodology/approach: Padding welds of investigated alloys were tested for three cases: after laser...

BACKGROUND High intensity focused ultrasound (HIFU) has gained clinical interest as a non-invasive local tumour therapy in many organs. In addition, it has been shown that lung cancer can be targeted by HIFU using One-Lung Flooding (OLF). OLF generates a gas free saline-lung compound in one lung wing and therefore acoustic access to central lung tumours. It can be assumed that lung parenchyma i...

A simple mathematical expression is presented to describe cavitation mean depth of erosion versus time for cavitating jets and ultrasonic cavitation. Following normalization with a characteristic time, t*, which occurs at 75% of the time of maximum rate of erosion, and a corresponding material characteristic mean erosion depth, h*, the normalized erosion depth is related to the normalized time ...

The phenomenon of cavitation is widely experienced in both pumps and under-water components of hydro power plants. The mechanism of material damage during cavitation is mainly attributed to implosion of high velocity bubbles on to the surface giving raise to local increase in stresses in excess of 1.4 GPa. In addition, material wastage due to particle induced erosion is observed in hydro plants...

This research determines which of the phenomena that appear during cavitation are responsible for the erosion of some brittle water soluble materials, such as gypsum and alum, when exposed to a high intensity ultrasound field over the cavitation level. The observation that gypsum suffers no erosion under the effect of an ultrasound field when the material is irradiated in a saturated solution o...

A new sonochemical process for the top-down production of silicon nanoparticles (<1 nm) with surface functional groups is described. The procedure involves a combination of acoustic cavitation erosion of a single-crystalline silicon surface coupled with simultaneous reaction with a reactive organic compound such as 1-hexyne. The sonochemical formation of the photoluminescent silicon nanoparticl...

In some circumstances the erosive effects of inertial (transient) cavitation have been usefully employed in the acceleration of chemical processes that are dependent on surface reactions. However, in other situations the erosion of materials can be detrimental. For example erosion/corrosion phenomena have been well documented. It will be demonstrated here that the employment of inertial cavitat...

The internal flow in the rotating bucket of Pelton turbine is free water sheet flow with moving boundary. The runner operates under atmospheric and the cavitation in the bucket is still a controversial problem. While more and more field practice proved that there exists cavitation in the Pelton turbine bucket and the cavitation erosion may occur at the worst which will damage the bucket. So a w...