CAJ | 학술논문

应用二维不可压缩N-S方程结合改进VOF空化模型模拟了NACA66二维翼的空化流动.数值计算中采用SST k-ω湍流模型计算了不同空泡数下定常稳态空化发生时水翼吸力面的压力分布,并与实验结果进行对比,发现空化末端压力梯度计算值明显大于实验值,而且压力有明显突增,通过修正空化模型中的经验参数较好地解决了这个问题.应用SST-SAS湍流模型及修正的经验参数较好地模拟了低空泡数时非定常云空泡的脱落现象,该数值方法对非稳态空化的发展,脱落过程及其频率的预报结果与实验结果吻合良好.
응용이유불가압축N-S방정결합개진VOF공화모형모의료NACA66이유익적공화류동.수치계산중채용SST k-ω단류모형계산료불동공포수하정상은태공화발생시수익흡력면적압력분포,병여실험결과진행대비,발현공화말단압력제도계산치명현대우실험치,이차압력유명현돌증,통과수정공화모형중적경험삼수교호지해결료저개문제.응용SST-SAS단류모형급수정적경험삼수교호지모의료저공포수시비정상운공포적탈락현상,해수치방법대비은태공화적발전,탈락과정급기빈솔적예보결과여실험결과문합량호.
Cavitating flow around a 2-dimentional NACA 66 hydrofoil was simulated using 2D incompressible Navier-Stokes equation with modified VOF cavitation model. In the numerical modeling, the pressure distribution on the suction side was calculated for different cavitation numbers using SST k-ω turbulence model. The calculated pressure gradient is quite steep and the pressure has an obvious peak in the closure region of the cavity, which does not well agree with experimental results. The problem was solved by modifying the empirical parameters of the cavitation model. Then, the unstable cavity shedding at lower cavitation numbers can be well predicted using SST-SAS turbulence model and the modified empirical parameters. The calculated results show that the predicted cavity growth and shedding process and its frequency agree well with experimental data.