基于神经网络的线性稳定性分析方法

Linear stability analysis based on neural network

  • 摘要: 在实现eN方法时需要搜索流场中的不稳定波并大量求解当地边界层的稳定性问题,因此,为高效求解当地边界层的不稳定波参数,本文提出了一种基于神经网络的线性稳定性分析方法(NN-LSA),使用平板数据集训练神经网络模型,并利用平板和尖锥算例进行验证。该方法采用卷积神经网络 ( convolutional neural network, CNN)给出最不稳定波频率、展向波数、流向波数和增长率的初值对,再通过迭代法计算失稳扰动波的实际空间失稳波数和增长率。结果表明,NN-LSA方法求解出的流场中最不稳定波的特征与传统全局搜索方法一致,相比传统方法,求解效率有较大提高,大大减少了人为因素在稳定性计算过程中的影响。本文提出的方法可以实现自动分析边界层流动的线性稳定性,具有一定的实用潜力。

     

    Abstract: The eN method, which has been widely used for predicting boundary-layer transition, necessitates a meticulous search for unstable modes by solving a large number of local boundary-layer stability problems, a process that can be very time-consuming. This paper proposes a novel neural network-based linear stability analysis method, NN-LSA, that leverages convolutional neural networks to generate an initial guess of the frequency, streamwise and spanwise wave numbers, and growth rate of the most unstable mode. Subsequently, the actual values are iteratively calculated based on this initial guess.,The primary advantage of NN-LSA over the traditional eN method lies in its ability to mitigate the influence of human factors in the stability analysis process, thereby facilitating automatic stability analysis. The application of NN-LSA in boundary layers over flat plates and a sharp cone demonstrates that NN-LSA can obtain characteristics of the most unstable modes consistent with those obtained by traditional global search methods. More importantly, NN-LSA trained by databases of boundary layers over flat plates can be successfully applied in the stability analysis of the boundary layer over a zero-angle-of-attack sharp cone, underscoring its generalization ability.

     

/

返回文章
返回