Flow field reconstruction method based on array neural network

2020 ◽  
Vol 125 (1283) ◽  
pp. 223-243
Author(s):  
W. Yuqi ◽  
Y. Wu ◽  
L. Shan ◽  
Z. Jian ◽  
R. Huiying ◽  
...  

ABSTRACTMulti-dimensional aerodynamic database technology is widely used, but its model often has the curse of dimensionality. In order to solve this problem, we need projection to reduce the dimension. In addition, due to the lack of traditional method, we have improved the traditional flow field reconstruction method based on artificial neural networks, and we proposed an array neural network method.In this paper, a set of flow field data for the target problem of the fixed Mach number is obtained by the existing CFD method. Then we arrange all the sampled flow field data into a matrix and use proper orthogonal decomposition (POD) to reduce the dimension, whose size is determined by the first few modals of energy. Therefore, significantly reduced data are obtained. Then we use an arrayed neural network to map the flow field data of simplified target problem and the flow field characteristics. Finally, the unknown flow field data can be effectively predicted through the flow field characteristic and the trained array neural network.At the end of this paper, the effectiveness of the method is verified by airfoil flow fields. The calculation results show that the array neural network can reconstruct the flow field of the target problem more accurately than the traditional method, and its convergence speed is significantly faster. In addition, for the case of high angle flow field, the array neural network also performs well. There are no obvious jumps, and huge errors are found in results. In general, the proposed method is better than the traditional method.

2019 ◽  
Vol 27 (8) ◽  
pp. 11413 ◽  
Author(s):  
Xiangju Qu ◽  
Yang Song ◽  
Ying Jin ◽  
Zhenyan Guo ◽  
Zhenhua Li ◽  
...  

2019 ◽  
Vol 45 (11) ◽  
pp. 3042-3055 ◽  
Author(s):  
Xinhuan Zhou ◽  
Peter Vincent ◽  
Xiaowei Zhou ◽  
Chee Hau Leow ◽  
Meng-Xing Tang

2013 ◽  
Vol 192 ◽  
pp. 10-19 ◽  
Author(s):  
Monirosadat Sadati ◽  
Clarisse Luap ◽  
Beat Lüthi ◽  
Martin Kröger ◽  
Hans Christian Öttinger

2020 ◽  
Vol 12 (14) ◽  
pp. 2293
Author(s):  
Shuheng Zhao ◽  
Denghong Liu ◽  
Qiangqiang Yuan ◽  
Jie Li

Mercury, the enigmatic innermost planet in the solar system, is one of the most important targets of space exploration. High-quality gravity field data are significant to refine the physical characterization of Mercury in planetary exploration missions. However, Mercury’s gravity model is limited by relatively low spatial resolution and stripe noises, preventing fine-scale analysis and applications. By analyzing Mercury’s gravity data and topography data in the 2D spatial field, we find they have fairly high spatial structure similarity. Based on this, in this paper, a novel convolution neural network (CNN) approach is proposed to improve the quality of Mercury’s gravity field data. CNN can extract the spatial structure features of gravity data and construct a nonlinear mapping between low- and high-degree data directly. From a low-degree gravity input, the corresponding initial high-degree result can be obtained. Meanwhile, the structure characteristics of the high-resolution digital elevation model (DEM) are extracted and fused to the initial data, to get the final stripe-free result with improved resolution. Given the paucity of Mercury’s data, high-quality lunar datasets are employed as pretraining data after verifying the spatial similarity between gravity and terrain data of the Moon. The HgM007 gravity field obtained by the MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) mission at Mercury is selected for experiments to test the ability of the proposed algorithm to remove the stripes caused by quality differences of the highly eccentric orbit data. Experimental results show that our network can directly obtain stripe-free and higher-degree data via inputting low-degree data and implicitly assuming a lunar-like relation between crustal density and porosity. Albeit the CNN-based method cannot be sensitive to subsurface features not present in the initial dataset, it still provides a new perspective for the gravity field refinement.


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