基于聚合多重网格方法的跨音速颤振的数值模拟

采用流固耦合方法对跨音速颤振进行了数值模拟。流体方面在非结构网格上用有限体积方法求解了Euler方程；结构方面则求解了后掠机翼典型剖面的结构模态方程。时间推进采用双时间步长：对每一真实时间步，都通过基于聚合多重网格方法的伪时间步推进，对流体和结构方程交替迭代．得到一个稳态的流固耦合的解。文章最后给出了NACA64A010翼型剖面的跨音速颤振边界．与相关文献的计算结果符合良好。

Numerical simulation of transonic flutter based on agglomeration multigrid method

An efficient fluid-structure interaction solver based on agglomeration multigrid is developed in this paper. The unsteady Euler equations are fully coupled with the modal dynamic equations of a typical Isogai wing section and integrated forward in time. CFD solver is based on an unstructured finite volume algorithm and the Roe's upwind scheme is used for fluxes computation. The whole mesh moves rigidly with the airfoil without any deformation, which simplifies the procedure to compute the grid speed on control volume boundary. Aeroelastic system is decomposed for the two degree of freedom and integrated using a direct procedure. The whole system (fluid equations and structural modal equations) is marched implicitly in time using a dual time stepping method: at every real time step, a fully converged CFD-CSD solution is achieved by pseudo time marching which is accelerated by the agglomeration multigrid method. A steady transonic case of NACA0012 is first given to verify the efficiency of the agglomeration multigrid. Five level grids are used and the convergent rate is increased at least one order without losing any accuracy. Finally the Isogai test case which has been widely numerically investigated is studied. Flutter boundary prediction for a typical wing section NACA 64A010 is present and compared well with correlational references.