摘要
针对直升机旋翼CFD仿真的复杂性,提出了改进的适合于格心格式求解器的非结构嵌套网格算法。采用自适应网格技术在旋翼流场仿真的整个过程中进行网格的自适应加密和疏化操作,以更好地捕捉桨尖涡等流动细节。对于频繁的自适应过程中产生的大量重复点和无用点,采用了高效的交替数字树算法(Alternating digital tree,ADT)和标记-删除-移动算法(Mark,delete,move,MDM)进行删除,节约了不必要的存储。针对格心格式的求解器,采用了基于梯度的网格间插值方式,简化了网格间数值传递的复杂性,同时不降低求解器的精度。对Caradonna&Tung旋翼悬停算例和HLISHAPE 7A旋翼悬停算例进行了模拟验证,计算值与实验值吻合,表明本文建立的方法具有良好的鲁棒性和有效性。最后,与未采用自适应时求解器对桨尖涡的捕捉效果进行了对比,结果表明本文所采用的方法可以明显地提高求解器对桨尖涡的捕捉。
In order to deal with the fluid simulation of the rotor,an algorithm for overset mesh system based on unstructured grids is built.It is suitable for the CFD solver of cell-centred scheme.To capture the blade vortex,the Cartesian grid is adapted all the time during the fluid simulation of the rotor.Alternating digital tree(ADT)algorithm and make,delete,move(MDM)algorithm are used to delete amounts of unused and repeated points generated in every adaptive process.An interpolation method based on gradient is adopted,which greatly simplifies the complexity of the numerical transmission between grids and can satisfy the requirement of accuracy.For Caradonna&Tung and HLISHAPE 7A rotors,calculation in hovering state is conducted and the results are corresponding with the exp erimental data.It indicates that the algorithm is robust and efficient.After that,the results about capturing blade tip vortex are compared with the simulation without utilizing adaptive gird.It shows that the algorithm can significantly improve the resolution of capturing the blade tip vortex.
作者
桑树浩
孙振航
陈仁良
李赟
SANG Shuhao;SUN Zhenhang;CHEN Renliang;LI Yun(National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics,Nanjing University of Aeronaut ics&Astronautics,Nanjing,210016,China)
出处
《南京航空航天大学学报》
EI
CAS
CSCD
北大核心
2018年第4期528-535,共8页
Journal of Nanjing University of Aeronautics & Astronautics
基金
江苏高校优势学科建设工程资助项目
南京航空航天大学研究生创新基地(实验室)开放基金(kfjj20160101)资助项目
中央高校基本科研业务费专项基金资助项目
