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Accurately predicting hypersonic transitional flow on cone via a symmetry approach

Chinese Journal of Aeronautics 2023年第7期36卷 337-347页

作者： Weitao BI Kexin ZHENG Zhou WEI Zhensu SHE State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory of Aerodynamics and Computational Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China

A new algebraic transition model is proposed based on a Structural Ensemble Dynamics(SED)theory of wall turbulence,for accurately predicting the hypersonic flow heat transfer on *** model defines the eddy viscosity in terms of a two-dimensional multi-regime distribution of a Stress Length(SL)function,and hence is named as *** paper presents clear evidence of precise predictions of transition onset location and peak heat flux of a wide range of hypersonic Transitional Boundary Layers(TrBL)around straight cone at zero incidence,to an unprecedented accuracy as validated by over 70 measurements for varying five crucial influential factors(Mach number,temperature ratio,cone half angle,nose Reynolds number and noise level).The results demonstrate the universality of the postulated multi-regime similarity structure,in characterizing not only the spatial non-uniform distribution of the eddy viscosity in hypersonic TrBL on cone,but also the dependence of the transition onset location on the five influential *** latter yields a novel correlation formula for transition center Reynolds number which takes similar functional form as the SL function within the symmetry *** is concluded that the SED-SL model simulates TrBL around cone with uniformly high accuracy,and then points out to an optimistic alternative way to construct hypersonic transition model.

关键词： Cones Heat flux Hypersonic boundary layers Transition flow turbulence models

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Criteria of tracking vortex surfaces in turbulent-like flows

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Advances in Aerodynamics 2022年第1期4卷 96-114页

作者： Zishuo Han Yue Yang State Key Laboratory for Turbulence and Complex Systems College of EngineeringPeking UniversityBeijing100871China

We propose criteria of tracking vortex surfaces in complex flows based on the vortex-surface field (VSF). The criteria characterize the accuracy and Lagrangian tracking performance of the numerical VSF solution, and determine the time period when the vortex surface tracking is satisfactory. Moreover, we develop a turbulent-like flow combining large-scale coherent structures in the Taylor-Green flow and small-scale turbulent structures in homogeneous isotropic turbulence (HIT). From tracking of vortex surfaces during the effective tracking period, we find that the imposed HIT disturbance significantly wrinkles vortex surfaces. Subsequently, the wrinkled vortex tube with large vorticity magnitude tends to be further twisted, contributing to energy cascade, while the wrinkling is mitigated in the region with small vorticity magnitude.

关键词： Vortex dynamics turbulence Coherent structure Vortex-surface field

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Boundedness Analysis of Fully Distributed Event-Based Filtering 43

Boundedness Analysis of Fully Distributed Event-Based Filter...

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43rd Chinese Control Conference, CCC 2024

作者： Qian, Jiachen Duan, Zhisheng Zhang, Xilian Peking University State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering Science College of Engineering Beijing100871 China

ISBN: (纸本)9789887581581

This paper focuses on event-based distributed filtering problem for a discrete LTI system, where the data-scheduler can regulate the communication between the smart sensor and the estimator to balance a trade-off between communication cost and filtering performance. This paper aims to combine the framework of consensus-on-information-based distributed filtering (CIDF) and the theory of harmonic-coupled algebraic Riccati equations (HCRE) to accurately evaluate the performance of event-based distributed filter. It is shown that the performance of the event-based distributed filter can be uniformly bounded by the solutions to harmonic-coupled algebraic Riccat equations, only with the collective observability condition and primitivity of the adjacency matrix corresponding to the communication topology. Moreover, the upper bound of the communication rate is also proposed in the form o the solutions to HCRE, which is more specific compared with the literature. Finally, the correctness of the theoretical results is demonstrated by several comparative numerical examples. © 2024 Technical Committee on Control Theory, Chinese Association of Automation.

关键词： Riccati equations

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Data-Driven Multi-Objective Optimization of Power Consumption and Quality for Finishing Rolling Process 13

Data-Driven Multi-Objective Optimization of Power Consumptio...

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13th IEEE Data Driven Control and Learning systems Conference, DDCLS 2024

作者： Chen, Xiaolu Yang, Ying College of Engineering Peking University State Key Laboratory for Turbulence & Complex Systems Department of Mechanics and Engineering Science Beijing100871 China

ISBN: (纸本)9798350361674

This paper investigates the operational optimization in the context of the steel hot rolling production and finishing facilities. Optimizing the operational variables of the finishing rolling process can improve the rolling quality and reduce the unit power consumption. However, there are too many operational variables in the process and their interactions are strongly coupled, making it difficult to develop an effective model for in-depth study. Therefore, this paper adopts a data-driven approach, using neural network algorithms to construct the data prediction models between performance and set values respectively. Multi-objective optimization of the set values is performed by combining the actual mechanism and equipment constraints. In the obtained Pareto optimal solutions, the conflicting choices are further balanced among multiple objectives to obtain the most suitable operating parameters. Experimentally verified using production line production data, the method proposed in this paper significantly improves the performance indexes. © 2024 IEEE.

关键词： Multiobjective optimization

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Completely Distributed Adaptive Observer for Unknown Linear System 43

Completely Distributed Adaptive Observer for Unknown Linear ...

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43rd Chinese Control Conference, CCC 2024

作者： Cao, Yuxi Wang, Jinzhi College of Engineering Peking University State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering Science Beijing100871 China

ISBN: (纸本)9789887581581

In this paper, a distributed adaptive observer scheme is designed for state reconstruction of linear time-invariant (LTI) systems with unknown dynamics. Specifically, a set of sensor nodes are deployed to distributedly measure the system state information, to restore the state and dynamics within it. Due to limitation of measurement capacity, individual node may not be able to measure the entire state. By achieving consensus with neighbors through a communication network, each node can adaptively reconstruct the system dynamics and estimate the system state asymptotically. The design of distributed adaptive observers for LTI systems with no input and with bounded unknown input are discussed, respectively. The completely distributed design in this paper requires no global information such as communication topology, collective measurement channel, or bound of the components of the system dynamics. © 2024 Technical Committee on Control Theory, Chinese Association of Automation.

关键词： Sensor nodes

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Decentralized Game-based Auction Algorithm for Scheduling Robotic Chargers to Service EVs with Uncertain Demands

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年 1-14页

作者： Fang, Qiuyang Zhang, Jianlei Wang, Chen Xie, Guangming Zhang, Chunyan Department of Automation College of Computer and Control Engineering Nankai University Tianjin China National Engineering Research Center of Software Engineering Peking University Beijing China State Key Laboratory for Turbulence and Complex Systems Intelligent Biomimetic Design Lab College of Engineering Peking University Beijing China

In this study, we introduce a novel auction-based algorithm modeled as a decentralized coalition formation game, designed for the complex requirements of large-scale multi-robot task allocation under uncertain demand. This context is particularly illustrative in scenarios where robots are tasked to charge electric vehicles. The algorithm begins by partitioning a composite task sequence into distinct subsets based on spatial similarity principles. Subsequently, we employ a coalition formation game paradigm to coordinate the assembly of robots into cooperative coalitions focused on these distinct subsets. To mitigate the impact of unpredictable task demands on allocations, our approach utilizes the conditional value-at-risk to assess the risk associated with task execution, along with computing the potential revenue of the coalition with an emphasis on risk-related outcomes. Additionally, integrating consensus auctions into the coalition formation framework allows our approach to accommodate assignments for individual robot-task pairings, thus preserving the stability of individual robotic decision autonomy within the coalition structure and assignment distribution. Simulative analyses on a prototypical parking facility layout confirm that our algorithm achieves Nash equilibrium within the coalition structure in polynomial time and demonstrates significant scalability. Compared to competing algorithms, our proposal exhibits superior performance in resilience, task execution efficiency, and reduced overall task completion times. The results demonstrate that our approach is an effective strategy for solving the scheduling challenges encountered by multi-robot systems operating in complex environments. IEEE

关键词： Polynomial approximation

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Theoretical and experimental investigation of the resonance responses and chaotic dynamics of a bistable laminated composite shell in the dynamic snap-through mode

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 581-602页

作者： Meiqi WU Pengyu LV Hongyuan LI Jiale YAN Huiling DUAN Wei ZHANG State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceBIC-ESATCollege of EngineeringPeking UniversityBeijing 100871China Nanchang Innovation Institute of Peking University Nanchang 330096China Department of Mechanics Guangxi UniversityNanning 530004China

The dynamic model of a bistable laminated composite shell simply supported by four corners is further developed to investigate the resonance responses and chaotic *** existence of the 1:1 resonance relationship between two order vibration modes of the system is *** resonance response of this class of bistable structures in the dynamic snap-through mode is investigated,and the four-dimensional(4D)nonlinear modulation equations are derived based on the 1:1 internal resonance relationship by means of the multiple scales *** Hopf bifurcation and instability interval of the amplitude frequency and force amplitude curves are *** discussion focuses on investigating the effects of key parameters,e.g.,excitation amplitude,damping coefficient,and detuning parameters,on the resonance *** numerical simulations show that the foundation excitation and the degree of coupling between the vibration modes exert a substantial effect on the chaotic dynamics of the ***,the significant motions under particular excitation conditions are visualized by bifurcation diagrams,time histories,phase portraits,three-dimensional(3D)phase portraits,and Poincare ***,the vibration experiment is carried out to study the amplitude frequency responses and bifurcation characteristics for the bistable laminated composite shell,yielding results that are qualitatively consistent with the theoretical results.

关键词： bistable laminated composite shell dynamic snap-through mode Hopf bifurcation chaotic dynamics vibration experiment

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A Structure-Preserving Learning Scheme on SO(3) 43

A Structure-Preserving Learning Scheme on SO(3)

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43rd Chinese Control Conference, CCC 2024

作者： Li, Tianzhi Wang, Jinzhi Peking University State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering Science College of Engineering Beijing100871 China

ISBN: (纸本)9789887581581

Gaussian process regression has been extensively studied due to its ability for learning and predicting a dynamic process. Though this data-driven approach has received considerable attention, it shows the drawback of ignoring the physical prior of the system. In this paper, a structure-preserving Gaussian process regression is proposed for learning and predicting the SO(3) dynamics. The dynamics of the satellite is represented under the framework of geometric mechanics, which results in a reduced equations of motion. As such, by using variational mechanics the priori estimation is constructed to determine the posteriori mean during the Gaussian process regression. The obtained learning method inherits the advantages of the numerical integrator, such as energy-conserving and constraint-preserving. The benefits of the proposed approach are highlighted in a numerical simulation with a real cuboid satellite. © 2024 Technical Committee on Control Theory, Chinese Association of Automation.

关键词： Gaussian process regression structure preservation Variational principle

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Cooperative Output Regulation of Heterogeneous systems over Directed Graphs:A Dynamic Adaptive Event-Triggered Strategy

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Journal of systems Science & complexity 2023年第3期36卷 909-921页

作者： SU Hang CHENG Bin LI Zhongkui State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing 100871China Department of Control Science and Engineering College of Electronics and Information EngineeringTongji UniversityShanghai 201804China Frontiers Science Center for Intelligent Autonomous Systems Shanghai 201210China

This paper investigates the cooperative output regulation problem of heterogeneous linear multi-agent systems over directed graphs with the constraint of communication *** that there exists an exosystem whose state information is not available to all agents,the authors develop distributed adaptive event-triggered observers for the followers based on relative information between neighboring *** should be pointed out that,two kinds of time-varying gains are introduced to avoid relying on any global information associated with the network,and dynamic triggering conditions are designed to get rid of continuous *** the basis of the designed observers,the authors devise a local controller for each *** with the existing related works,the main contribution of the current paper is that the cooperative output regulation problem for general directed graphs is solved requiring neither global information nor continuous communications.

关键词： Adaptive control consensus cooperative output regulation directed graph event-triggered control multi-agent systems

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The Boundary Element Method for Ordinary state-Based Peridynamics

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Computer Modeling in engineering & Sciences 2024年第6期139卷 2807-2834页

作者： Xue Liang Linjuan Wang State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceCollege of EngineeringPeking UniversityBeijing100871China CAPT-HEDPS and IFSA Collaborative Innovation Center of MoECollege of EngineeringPeking UniversityBeijing100871China School of Astronautics Beihang UniversityBeijing100191China

The peridynamics(PD),as a promising nonlocal continuum mechanics theory,shines in solving discontinuous *** to now,various numerical methods,such as the peridynamic mesh-free particlemethod(PD-MPM),peridynamic finite element method(PD-FEM),and peridynamic boundary element method(PD-BEM),have been ***-BEM,in particular,outperforms other methods by eliminating spurious boundary softening,efficiently handling infinite problems,and ensuring high computational ***,the existing PD-BEM is constructed exclusively for bond-based peridynamics(BBPD)with fixed Poisson’s ratio,limiting its applicability to crack propagation problems and scenarios involving infinite or semi-infinite *** this paper,we address these limitations by introducing the boundary element method(BEM)for ordinary state-based peridynamics(OSPD-BEM).Additionally,we present a crack propagationmodel embeddedwithin the framework ofOSPD-BEM to simulate crack *** validate the effectiveness of OSPD-BEM,we conduct four numerical examples:deformation under uniaxial loading,crack initiation in a double-notched specimen,wedge-splitting test,and threepoint bending *** results demonstrate the accuracy and efficiency of OSPD-BEM,highlighting its capability to successfully eliminate spurious boundary softening phenomena under varying Poisson’s ***,OSPDBEMsignificantly reduces computational time and exhibits greater consistencywith experimental results compared to PD-MPM.

关键词： Ordinary state-based peridynamics boundary element method crack propagation fracture toughness

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