用动网格法计算理想平板的颤振导数

提出了一种数值模拟振动的理想平板绕流场 ,并提取其气动导数的方法。时间相关的不可压N S方程采用Projetion 2格式解耦 ,关于中间速度的动量方程的时间和空间离散采用二阶半隐格式 ,压力Possion方程迭代用多层网格法加速收敛。分别计算平板作竖向强迫振动或扭转强迫振动的气动力 ,用动网格法考虑平板和气流的耦合作用。由计算得到的气动力用最小二乘法确定 8个气动导数。计算结果和理想平板的Theodorsen理论值有较好的一致性

Assessment of Aerodynamic Derivatives of the Ideal Flat Plate Based on the Moving Grid Method

Numerical simulation of the flow field around the oscillating ideal flat plate is presented to assess the aerodynamic derivatives. The time-dependent incompressible Navier-Stokes equations are decoupled using Projection-2 method. The second order semi-implicit scheme is employed in temporal and spatial discretization for the momentum equations of intermediate velocities, while the Possion's equation for pressure is solved efficiently by using the multigrids method. Unsteady aerodynamic force on the heaving or pitching oscillated flat plate are computed and the motion of the plate is accounted by the moving grid method. The aerodynamic derivatives are extracted with the Least Square Method. The computed aerodynamic derivatives are in better agreement with Theodorsen's theoretic solutions.