• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.11-12
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• 2006

We conducted a direct numerical simulation (DNS) to establish database for the purpose of improvement of practical method which is applicable to cavitating turbulent flows. Cavitations caused by spanwise and streamwise vortices, which are typical features in high shear layer, is represented by a simple model and interaction between vortices and cavities is reproduced. The qualitative agreement between computation and experiment are reasonable. Cavities due to streamwise vortices in a shear layer seem to attenuate turbulent eddies.

• 대한조선학회논문집
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• 제48권3호
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• pp.233-237
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• 2011

In the present experiments, vortical structures behind the hydrofoil trailing edge are visualized and analyzed as an elementary study for propeller singing phenomena. Two sorts of hydrofoil are selected for the measurement of shedding vortices. One was KH45 hydrofoil section and the other is KH45 with the truncated trailing edge that is positioned at X/C = 0.9523(C=chord length). Assuming the Strouhal number of 0.23, the shedding frequencies of vortices are extracted by analyzing the boundary layer thickness and the flow speed. The frequency distribution of shedding vortices is obtained with the variation of angle-of-attack while the flow speed is fixed to 8m/s. The truncation of the trailing edge makes the frequency of shedding vortices about 120Hz lower than that of original trailing edge and makes the vorticity value higher than the original trailing edge.