论文部分内容阅读
由正交Walsh函数构造Walsh-单信号-复合-输入,对其作用下的计算流体力学响应采用单信号-复合-输入/特征系统实现算法SCI/ERA(Single-Composite-Input/Eigensystem Realization Algorithm)辨识得到离散时间非定常气动力状态空间降阶模型。通过对Isogai机翼剖面气动弹性算例的计算证明该方法具有和非定常计算流体力学方法相当的精度同时模型维数降低2个数量级;在模型构造时间上,SCI/ERA方法比脉冲/ERA方法计算效率提高24%,同时内存占用减小34%;由理论分析可知当耦合结构模态数目增加时,SCI/ERA方法所需的计算开销增幅远小于脉冲/ERA方法;采用频域平衡特征正交分解BPOD(Balanced Proper Orthogonal Decomposition)方法可以准确地从降阶模型中提取出一个低频二次降阶模型,同时保持与原模型相当的精度。二次降阶后模型维数进一步减小88%。
The Walsh-monosignal-complex-input is constructed by orthogonal Walsh function. The computational fluid dynamics (CFD) response of the Walsh-single-composite-input / Identify the reduced order model of unsteady aerodynamic state space in discrete time. Computation of the aeroelasticity of the Isogai airfoil section proves that this method has the same accuracy as the unsteady CFD method and the model dimension is reduced by two orders of magnitude. In model construction time, the SCI / ERA method is more accurate than the pulse / ERA method The computational efficiency is improved by 24% and the memory occupation is reduced by 34%. The theoretical analysis shows that the computational cost increase required by the SCI / ERA method is much smaller than that of the pulse / ERA method when the number of coupled structures increases. The BPD (Balanced Proper Orthogonal Decomposition) method can accurately extract a low frequency quadratic reduction model from the reduced order model, while maintaining the accuracy comparable to the original model. After the second order reduction, the dimension of the model is further reduced by 88%.