exploring-the-deep-reinforcement-learning-in-fluid-engineering

当前,深度强化学习在工业流体力学中的应用得到了广泛关注。工业领域,尤其是航天航空、海洋船舶及能源动力等行业,有大量流体控制及优化设计的难题趋待解决。发掘此类方法的极限潜力仍需要一定的时间,特别是针对处理工业流体力学中无理论最优解的控制问题及优化设计。传统方法在流动控制及优化设计领域面临应对非线性及高维复杂性挑战,人工智能的飞速发展带来了新的希望,其中深度强化学习为解决流体控制及优化设计提供了一个崭新的手段。本期聚焦深度强化学习在流动控制及优化设计中的应用,以探索深度强化学习在相关领域应用潜力。本期内容来自2019年12月13日至16日在上海召开的“高保真计算方法及应用国际会议”中人工智能讨论专题,探讨未来基于高保真数据驱动的人工智能在流体力学中的深入应用。

在本期专栏中,我们主要关注深度强化学习研究,探讨算法和新应用的问题。稿件包含三篇论文:在第一篇论文“Deep reinforcement learning in fluid mechanics: A promising method for both active flow control and shape optimization(https://doi.org/10.1007/s42241-020-0028-y,share this article: https://rdcu.be/b4PPe)”中,作者就深度强化学习在流体力学中的先进应用做了综述,包含人工神经网络、监督学习、深度强化学习及在流动控制及形状优化设计中的应用。第二篇论文“Active flow control using machine learning: A brief review”(https://doi.org/10.1007/s42241-020-0026-0,share this article: https://rdcu.be/b4QgL,)中,作者就机器学习在主动控制中的应用做了综述,包含基于遗传编程的主动控制、基于深度学习的主动控制及未来的挑战和展望。第三篇论文“Active flow control with rotating cylinders by an artificial neural network trained by deep reinforcement learning”( https://doi.org/10.1007/s42241-020-0027-z,share this article:https://rdcu.be/b4QgN)中,作者就深度强化学习在流动控制中应用做了实践研究,内容主要涉及深度强化学习在圆柱尾迹控制中的应用及实施,展示了深度强化学习实施复杂流动控制的潜力。

(a)    深度强化学习控制

(b)    无控制

为加强交流以共同促进高保真计算方法、理论研究及工业领域的应用研究,2019年12月13日至16日,在上海召开了高保真计算方法及应用国际会议(International Symposium on High-Fidelity Computational Methods & Applications 2019)。在交叉学科领域,会议将机器学习及人工智能作为一个特别的专题,主要探讨高精度数据驱动下的机器学习及人工智能在流体力学中的应用,会议论文在Journal of Hydrodynamics上作为专栏进行了发表(https://link.springer.com/journal/42241/32/2),旨在推动相关方法在流动控制领域的广泛应用。特别需要指出,关于深度强化学习在流体力学中应用的相关研究得到了广泛关注。

 

客座编辑介绍:

徐辉,上海交通大学航空航天学院博士生导师,帝国理工荣誉研究员。主要从事流体力学、应用数学及计算数学、人工智能及机器学习在流体学中的应用研究,特别地致力于先进高精度科学计算方法研究及在流动稳定性、转捩、湍流、噪声及流动控制等方面的理论及工程应用研究。担任Journal of hydrodynamics编委。

张伟,中国船舶与海洋设计研究院,喷水推进技术重点实验室,高级工程师。主要从事流体力学、湍流与空化流动,以及人工智能及机器学习在流体力学中的应用研究。担任Journal of hydrodynamics编委。

CONTENTS OF JOURNAL OF HYDRODYNAMICS Vol.32 No.2 2020

https://link.springer.com/journal/42241/32/2

CONTENTS

FEATURE ARTICLE

Liutex theoretical system and six core elements of vortex identification
Yi-qian Wang, Yi-sheng Gao, Hongyi Xu, Xiang-rui Dong, Jian-ming Liu, Wen-qian Xu, Meng-long Chen, Chaoqun Liu(197)

REVIEW ARTICLE

Numerical techniques for coupling hydrodynamic problems in ship and ocean engineering
Xiao-song Zhang, Jian-hua Wang, De-cheng Wan(212)

SPECIAL COLUMN ON THE INTERNATIONAL SYMPOSIUM ON HIGH-FIDELITY COMPUTATIONAL METHODS AND APPLICATIONS 2019 (GUEST EDITORS HUI XU, WEI ZHANG)

Deep reinforcement learning in fluid mechanics: A promising method for both active flow control and shape optimization
Jean Rabault, Feng Ren, Wei Zhang, Hui Tang, Hui Xu(234)
Active flow control using machine learning: A brief review
Feng Ren, Hai-bao Hu, Hui Tang(247)
Active flow control with rotating cylinders by an artificial neural network trained by deep reinforcement learning
Hui Xu, Wei Zhang, Jian Deng, Jean Rabault(254)

SPECIAL COLUMN ON THE 3RD SYMPOSIUM ON COMPUTATIONAL MARINE HYDRODYNAMICS (GUEST EDITOR DE-CHENG WAN)

An unstructured mesh method for numerical simulation of violent sloshing flows
Changhong Hu, Mohamed M. Kamra(259)
A sharp-interface immersed smoothed point interpolation method with improved mass conservation for fluid- tructure interaction problems
Bo-qian Yan, Shuangqiang Wang, Gui-yong Zhang, Chen Jiang, Qi-hang Xiao, Zhe Sun(267)
Vortex identification methods in marine hydrodynamics
Wei-wen Zhao, Jian-hua Wang, De-cheng Wan(286)

ARTICLES

ARTICLES Law-of-the-wall analytical formulations for Type-A turbulent boundary layers
Duo Wang, Heng Li, Bo-chao Cao, Hongyi Xu(296)
Mean flow and turbulence structure of open channel flow with suspended vegetation
Qian Li, Yu-hong Zeng, Yu Bai(314)
Detached-eddy simulation of turbulent coherent structures around groynes in a trapezoidal open channel
Jing-xin Zhang, Jian Wang, Xiang Fan, Dongfang Liang(326)
Experimental study of anti-cavitation mechanism of valve lintel natural aeration of high head lock
Xin Wang, Ya-an Hu, Jian-min Zhang(337)
Large eddy simulation of the transient cavitating vortical flow in a jet pump with special emphasis on the unstable limited operation stage
Xin-ping Long, Dan Zuo, Huai-yu Cheng, Bin Ji(345)
Evolution characteristics and quantization of wave period variation for breaking waves
Shu-xiu Liang, Zhao-chen Sun, Yan-ling Chang, Ying Shi(361)
Erosion characteristics and mechanism of the self-resonating cavitating jet impacting aluminum specimens under the confining pressure conditions
Hua-lin Liao, Sheng-li Zhao, Yan-feng Cao, Lei Zhang, Can Yi, Ji-lei Niu, Li-hong Zhu(375)
Experimental study of wave propagation characteristics on a simplified coral reef
Jia-yi Xu, Shu-xue Liu, Jin-xuan Li, Wei Jia(385)
Large eddy simulation of cavitating flows with dynamic adaptive mesh refinement using OpenFOAM
Lin-min Li, Dai-qing Hu, Yu-cheng Liu, Bi-taoWang,Chen Shi, Jun-jie Shi, Chang Xu(398)
LETTER Fin performance of 3-D aerator devices with backward lateral deflectors
Jian-rong Xu, Jian-hua Wu, Yu Peng, Fei Ma(410)
Erratum
(414)

CONTENTS OF JOURNAL OF HYDRODYNAMICS Vol.32 No.1 2020

CONTENTS

SPECIAL COLUMN ON THE 3RD INTERNATIONAL SYMPOSIUM OF CAVITATION AND MULTPHASE FLOW (GUEST EDITORS HONG-XUN CHEN, WEI ZHANG)

Effect of compressibility on bubbly cavitating flows
Harish Ganesh, Anubhav Bhatt, Juliana Wu, Steven Ceccio(1)
Hydrodynamic mechanisms of aggressive collapse events in leading edge cavitation
Mohammad Hossein Arabnejad, Ali Amini, Mohamed Farhat, Rickard E. Bensow(6)
Numerical investigation on free surface effect on the supercavitating flow over a low aspect ratio wedge-shaped hydrofoil
Chang Xu, Boo Cheong Khoo(20)

ARTICLES

Numerical investigation of flow with floating vegetation island
Yi-dan Ai, Meng-yang Liu, Wen-xin Huai(31)
Numerical study of high-lift hydrofoil near free surface at moderate Froude number
Tao Xing, Konstantin I. Matveev, Miles P. Wheeler(44)
A dynamic solution for predicting resonant frequency of piston mode fluid oscillation in moonpools/narrow gaps
Lei Tan, Lin Lu, Guo-qiang Tang, Liang Cheng(54)
Wave action by arrays of vertical cylinders with arbitrary smooth cross-section
Jia-bin Liu, An-xin Guo, Qing-he Fang, Hui Li, Hui Hu, Peng-fei Liu(70)
Experimental investigation of vortex generator influences on propeller cavitation and hull pressure fluctuations
Hong-bo Huang, Yun Long, Bin Ji(82)
Drag reduction and flow structures of wing tip sails in ground effect
Jian-xun Zhou, Cheng-hong Sun, Daichin(93)
Slip in Couette flow with pressure gradient: Theoretical and experimental investigation of hydrodynamic characteristics considering slip effect
Xin Zhao, Chao Wei, Shi-hua Yuan(107)
Development of two-dimensional numerical wave tank based on lattice Boltzmann method
Guang-wei Liu, Qing-he Zhang, Jin-feng Zhang(116)
Study of parametric roll in oblique waves using a three-dimensional hybrid panel method
Min Gu, Shu-xia Bu, Jiang Lu(126)
Reconstruction of 3-D surface waves generated by moving submerged sphere based on stereo imaging principle
Xin-long Wang, Gang Wei, Hui Du, Shao-dong Wang(139)
Adaptive mesh refinement immersed boundary method for simulations of laminar flows past a moving thin elastic structure
Mohammed Suleman Aldlemy, Mohammad Rasidi Rasani, A. K. Ariffin, T. M. Y. S. Tuan Ya(148)
A design of T-foil and trim tab for fast catamaran based on NSGA-II
Qi-dan Zhu, Yu Ma(161)

LETTERS

Spatial and spectral investigation of turbulent kinetic energy in cavitating flow generated by Clark-Y hydrofoil
Xiao-rui Bai, Huai-yu Cheng, Bin Ji, Xin-ping Long(175)
Flow regime and energy dissipation of SFS-type flip buckets
Ran Tian, Jian-hua Wu, Fei Ma(179)
Numerical simulation of condensation shock in partial cavitating flow on a hydrofoil
Wei Zhang , Bing Zhu , Yong Wang, Hui Xu(183)
Journal of Hydrodynamics, Vol. 31 Annual Classified Catalog (2019).
(188)

B辑OA和SharedIt公告

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为了给作者、读者和编委提供更好的服务,为了提高我刊的影响力,经水动力学研究与进展编辑委员会做如下决定。

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特此通告,敬请悉知。

水动力学研究与进展编辑部

2019年12月18日

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Liutex Similarity of -5/3 Power Law

In the year of 1941, A. N. Kolmogorov, proposed that the small-scale turbulent motions are statistically isotropic at sufficient high Reynolds number, which is known as the Kolmogorov’s hypothesis of local isotropy. With other two hypotheses, Kolmogorov built up the celebrated Kolmogorov 1941 theory (in short K41). As the brightest jewel in the crown of K41 theory, the predicted -5/3 law for turbulence energy spectrum by the theory were confirmed by experiments almost a decade later. The assumptions taken by K41, however, cannot generally be satisfied in practical flows, especially for moderate and low Reynolds number boundary layers. Prof. Chaoqun Liu, the Tenured and Distinguished Professor from University of Texas at Arlington, proposed the extraction of rigid rotation from fluid motions in 2017, which is later named Liutex. Liu’s team discovered that, in a moderate and low Reynolds number turbulent boundary layer ( ), both the frequency and wavenumber spectrum of Liutex matches the -5/3 law in the higher frequencies (wavenumber) subrange very well while the turbulence energy spectrum, on the contrary, only marginally follows the -5/3 law in a much smaller wavenumber (frequency) range as shown in the following figure.

The much stronger universal similarity of Liutex’s -5/3 law over that of K41 comes from the fact that Liutex represents the rigid rotation part of fluid motion, which is shear free and thus not influenced by viscous effect and independent of Reynolds number. On the other hand, vorticity and other popular second-generation of vortex identification methods, Q criterion for example, do not possess this feature due to the shearing and stretching contamination. Not only does this work enhances people’s understanding towards physics of turbulence, but also could lead to a more universal subgrid model in large eddy simulation. The paper could be downloaded for free in two months (until Feburuary 25, 2020)

1.Xu W., Wang Y., Gao Y. et al. Liutex similarity in turbulent boundary layer [J]. Journal of Hydrodynamics, 2019, 31(6): 1259-1262.

https://link.springer.com/article/10.1007/s42241-019-1

https://rdcu.be/bZE59(click this link you can read the manuscript)

2.For more on Liutex vector please refer to the review paper:

Liu C., Gao Y., Dong X.R., et al. Third generation of vortex identification methods: Omega and Liutex/Rortex based systems [J]. Journal of Hydrodynamics, 2019, 31(2): 205–223.

https://link.springer.com/article/10.1007/s42241-019-0022-4

click the following link you can read the manuscript for free,

https://rdcu.be/bZQzS

Prof. Chaoqun Liu’s team has published more that 20 papers with Journal of Hydrodynamics and Physics of Fluids since 2018 on the third-generation of vortex identification methods: Liutex vector and Omega method. The software of the third-generation vortex identifcaiton methods has been published online at https://www.uta.edu/math/cnsm/public_html/cnsm/cnsm.html for free download with a short agreement for users to sign.