FLOW INDUCED NOISE & CAVITATION CONTROL LAB.
AUTHENTIC DISCOVERY OF CAVITATION
01 Bubbly Flow by Air Injection on an Inclined Hydrofoil
02 Experimental Investigation of Artificial Supercavitation
Experimental investigation on drag characteristics and flow physics of ventilated supercavitating objects with different body shapes were conducted. The test model consists of a disk-type cavitator with two different fore bodies (slender and blunt shape) and three different rear bodies (flat, shrinkage, and expanded shape). The drag forces acting on different body-combinations in fully wetted conditions are measured and the results show that the drag coefficients strongly depend on the body shapes. It explains in detail through particle image velocimetry measurements. The drag characteristics are systematically examined over a broad range of ventilation rates.
03 Coherent Structure of Turbulent Cavitating Flow
In many practical submerged objects, various types of cavitation such as bubble, sheet, and cloud cavitation occur according to flow conditions. In this work, the series process consisting of inception, growth, and desinence of the partial cavity was investigated, and also noise generated during the process was also measured. The results show that the periodic behavior of cavitation clouds is directly reflected in the noise characteristics. In addition, the visualization of coherent structures within the sheet and cloud cavity provides a qualitative understanding of hairpin vortices and their packets, which play a dominant role in turbulent cavitating flows.