POD方法在风洞试验二维速度场分析中的应用

针对风洞试验二维速度流场,构建了正交分解与流场重构的数学模型。通过对鼓包背风面PIV瞬时速度流场进行分解,发现阶数越低的模态对原始流场的能量贡献率越大,代表了流场中的低频、大尺度流动结构;反之,阶数越高的模态对原始流场的能量贡献率越小,代表了流场中的高频、小尺度流场结构等信息。通过对流场进行低维重构,发现前4阶重构流场几乎不受一些小尺度旋涡的影响,很清晰地显示了流场的主要结构。

Application of POD Method in 2D Velocity Flow Filed Analysis in Wind tunnel Test

A mathematical model is constructed to analyze velocity flow filed of wind tunnel test using POD method. Based on this model, the instantaneous velocity field at the leeward side of a bump is analyzed. The results show that the first few POD modes occupying most of the energy represent the large scale coherent structures that dominate the global flow field while higher POD modes occupying less energy represent the small scale structures and background noise. The reconstructed velocity field by the first four POD modes can exclude small scale flow structures, containing only large scale structures, which researchers are interested in.