CAJ | 학술논문

文章采用数值方法对绕水翼的非定常空化流动进行了流动计算，并采用涡动力学方法对非定常空化流场特性进行了分析。计算中，采用基于当地涡旋修正的湍流模型封闭控制方程，通过实验对该计算结果进行验证；采用涡量法分析了空化的发生和发展对涡量输运过程的影响。结果表明：基于当地涡旋修正的湍流模型可以准确地模拟水翼周围非定常空化流场结构；水翼空化流场具有强烈的非定常特性，空化的发展和流场中的涡结构有着紧密的联系；反向射流的作用会导致附着空穴尾缘附近速度梯度的非定常变化，是导致涡量产生和消失的重要因素；空化区域内部水气两相的质量交换会导致流场内体积变化率的变化，使得空化区域内部流体的非正压性显著增强，上述两者导致空化区域内部的涡量分布呈现强烈的非定常特性；空化现象引起的水气两相之间的相互转换以及对湍流的作用都是影响涡结构空间分布的重要因素。
문장채용수치방법대요수익적비정상공화류동진행료류동계산，병채용와동역학방법대비정상공화류장특성진행료분석。계산중，채용기우당지와선수정적단류모형봉폐공제방정，통과실험대해계산결과진행험증；채용와량법분석료공화적발생화발전대와량수운과정적영향。결과표명：기우당지와선수정적단류모형가이준학지모의수익주위비정상공화류장결구；수익공화류장구유강렬적비정상특성，공화적발전화류장중적와결구유착긴밀적련계；반향사류적작용회도치부착공혈미연부근속도제도적비정상변화，시도치와양산생화소실적중요인소；공화구역내부수기량상적질량교환회도치류장내체적변화솔적변화，사득공화구역내부류체적비정압성현저증강，상술량자도치공화구역내부적와량분포정현강렬적비정상특성；공화현상인기적수기량상지간적상호전환이급대단류적작용도시영향와결구공간분포적중요인소。
Unsteady cavitating flows around a hydrofoil are calculated. Vortex dynamics are used to ana-lyze the flow structure. Local swirling correction turbulence model is adopted to close the governing equa-tions. Validation of the LSC turbulence model can be reached comparing with experimental results. Vortici-ty transport equations are conducted to analyze the influence of cavitation on vorticity transport process. The results show that: The LSC turbulence model can reflect the influence of the local swirling on cavitating flows well. It can get a good compromise with experimental results. Unsteady cavitation process contains de-veloping of complex vortex structures. Re-entrant jet near trailing of attached cavity leads to distinct changes of velocity gradient, which has great influence on production and dissipation of vorticity. Intensive mass transfer between liquid and vapor phase may induce the volumetric expansion or contraction and baroclinic torque. Two factors mentioned above keep changing and result in unsteady distributions of vorticity. Cavi-tation may lead to unsteady mass and momentum transfers between liquid and vapor phase, which will change turbulence and vorticity distributions distinctly.