LES 모델을 이용한 NACA66 수중익 주변의 비정상 부분 캐비테이션 유동에 대한 거칠기 효과 = ROUGHNESS EFFECTS ON UNSTEADY PARTIAL CAVITATION FLOW AROUND NACA66 HYDROFOIL USING THE LES MODEL

다국어 초록 (Multilingual Abstract)

The wall roughness effects on unsteady unstable partial cavitation flow around NACA66 hydrofoil are numerically investigated using the Schnerr-Sauer cavitation model with the LES turbulence model. The wall roughness in the LES is modeled with Harmonic Blending wall functions based on the roughness Reynolds number. The roughness is applied to the three different zones of the suction side of the hydrofoil with different heights according to the non-dimensional roughness height. The numerical results show the correlations between the roughness effects and cavity behavior. The increased surface roughness leads to higher turbulent velocity. The turbulence destabilizes the sheet cavitation, leading to more rapid cavitation collapse or shedding. As a result, increased roughness surface leads to higher shedding frequency.

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