arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.00690physics.comp-phphysics.flu-dyn
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基于混合深度神经网络的动边界非定常流预测方法

Hybrid deep neural network based prediction method for unsteady flows with moving boundaries

Renkun Han, Zhong Zhang, Yixing Wang, Ziyang Liu, Yang Zhang, Gang Chen

摘要:

设计了一种新的混合深度神经网络架构,用于直接从高维非定常流场数据中捕获运动边界周围非定常流的时空特征。混合深度神经网络由卷积神经网络(CNN)、改进的卷积长短期记忆神经网络(ConvLSTM)和去卷积神经网络(DeCNN)构成。该混合深度神经网络可以通过前一时间步的流场和这些时间步的边界位置来预测未来时间步的流场。计算了不同振幅的强迫振荡圆柱周围的非定常尾流,以建立数据集作为训练混合深度神经网络的训练样本。然后通过预测具有新振幅的受迫振荡圆柱周围的非定常流场来测试训练的混合深度神经网络。分析了神经网络结构参数对预测精度的影响。由最佳参数组合构成的混合深度神经网络用于预测未来时间的流场。预测的流场与计算流体动力学求解器直接计算的流场吻合良好,这意味着这种深度神经网络可以从运动边界周围非定常流的时空序列中捕获精确的时空信息。结果表明,这种新型的混合深度神经网络在振动圆柱流动控制中具有潜在的能力,需要快速计算高维非线性非定常运动边界流动。

英文摘要:

A novel hybrid deep neural network architecture is designed to capture the spatial-temporal features of unsteady flows around moving boundaries directly from high-dimensional unsteady flow fields data. The hybrid deep neural network is constituted by the convolutional neural network (CNN), improved convolutional Long-Short Term Memory neural network (ConvLSTM) and deconvolutional neural network (DeCNN). Flow fields at future time step can be predicted through flow fields by previous time steps and boundary positions at those steps by the novel hybrid deep neural network. Unsteady wake flows around a forced oscillation cylinder with various amplitudes are calculated to establish the datasets as training samples for training the hybrid deep neural networks. The trained hybrid deep neural networks are then tested by predicting the unsteady flow fields around a forced oscillation cylinder with new amplitude. The effect of neural network structure parameters on prediction accuracy was analyzed. The hybrid deep neural network, constituted by the best parameter combination, is used to predict the flow fields in the future time. The predicted flow fields are in good agreement with those calculated directly by computational fluid dynamic solver, which means that this kind of deep neural network can capture accurate spatial-temporal information from the spatial-temporal series of unsteady flows around moving boundaries. The result shows the potential capability of this kind novel hybrid deep neural network in flow control for vibrating cylinder, where the fast calculation of high-dimensional nonlinear unsteady flow around moving boundaries is needed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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