针对旋翼流场模拟的自适应网格算法

Adaptive Grid Algorithm for Fluid Simulation of Rotor

针对基于格心格式求解器的旋翼流场模拟,提出了相应的自适应笛卡尔网格的数据存储结构及自适应算法。给出了相应的单元处理策略,简化了对自适应笛卡尔网格的处理;对于频繁的自适应加密过程中产生的大量重复点,采用了高效的交替数字树算法(Alternating digital tree,ADT)予以删除;对于自适应疏化过程中产生的大量无用点,提出了标记-删除-移动(Mark,delete,move,MDM)算法予以快速地删除,减少了不必要的计算资源消耗。对Caradonna&Tung旋翼在不同悬停状态下进行了模拟验证,对比了压力分布系数与桨尖涡位置。之后对HELISHAPE7A旋翼在前飞情况下进行了模拟验证,计算值与实验值吻合。此外,求解器对桨尖涡的捕捉效果得到了明显的提高,表明本文方法具有良好的有效性与鲁棒性。

The data structure,adaptive algorithm and the method of extracting cell information for adaptive Cartesian grid are introduced,which are designed for the CFD solver based on cell-centered scheme.Alternating digital tree(ADT)algorithm is used to delete amounts of repeated points generated in adaptive process.Mark,delete,move(MDM)algorithm is introduced to erase the unused points.For the Caradonna&Tung rotor in different hovering states,calculations are conducted.The distribution of pressure coefficient and the location of vertex are compared well with the experimental data.After that,the simulation for the HELISHAPE 7A rotor in forward state is conducted.It shows that the computation data are compared well with experimental data.It indicates that the algorithms are efficient and robust.The blade tip vortex is compared with the case without utilizing adaptive gird.It manifests that adaptive grid can significantly improve the resolution of capturing the blade tip vortex.