Invited Talks

Praveen Agarwal
Anand International College of Engineering, Rajasthan, India

Title: To be updated

To be updated.

Jan Awrejcewicz
Lodz University of Technology, Poland

Title: To be updated

To be updated.

Valentina Emilia Balas
Aurel Vlaicu University of Arad,  Romania

Title: To be updated

To be updated.

Dumitru Baleanu
Cankaya University, Turkey

Fractional Calculus and A I: Theory and Applications

To be updated.

Jose Balthazar
Member of Academy of sciences (ACIESP), SP, Brazil
Universidade Estadual Paulista, Brazil

What Does Nonideal Transportation Mechanisms in MACRO  and MEMS Scales Mean? Present, Past, & Future Directions Considering Regular and Irregular Motions

On the actual demand of modern technology, in the modeling of such structures, it is unavoidable to consider nonlinearities of the basic equations.  New phenomena in Dynamics as well as new approaches to older ones are expected to be discovered in the theoretical, numeric, and experimental investigations of those structures. It is also well known that the study of problems involving the coupling of several systems was widely explored, in the last years, essentially in function of the change of constructive characteristics of the machines and structures. Accordingly, oscillatory processes can be divided into the following types: free, forced, parametric and self-excited oscillations and we remarked that two or more oscillations can interact in the same oscillatory system. This fact is of important scientific and practical interest. In this way, some phenomena were observed in a composed dynamic system supporting structures and rotating machines, where was verified that the unbalancing of the rotating parts was the greatest causer of the vibrations.We also  noted that a lot of oscillatory(vibrating) phenomena of real systems cannot be explained by and solved based on linear theory, and it is important to introducing nonlinear characteristics into the mathematical models of vibrating systems and to electro-mechanical systems The main difficulty in comparisons of linear systems mainly because of absence of validity of superposition principle. Every nonlinear vibrating system must be solved individually, and special methodology must be developed for each class of problems.  Here, we will deal with a special class of nonlinear systems called non-ideal systems (NIS).

 

This  lecture  deals with the non-linear Electro-mechanical Systems analysis of a block ( portal)foundation structure for an unbalanced rotating machine, with limited power, leading to the interaction between the motor and the structure(RNIS).This aspect is often not considered during the usual design practice, although all real motors are, in this sense, non-ideal energy sources coupled to the structure to describe the most real behavior for these structures. Nonlinear dynamic coupling between energy sources and structural response should not be ignored in real engineering problems, as real motors (agitators and so on) have limited output power. Therefore, numerical, and analytical methods are applied for such analyzes to better understand the non-linear dynamics of these systems. However, the common phenomena for these systems are the Sommerfeld effect, the occurrence of the saturation phenomenon and so on.

 

 So, this lecture addresses the nonlinear dynamical analysis of a block foundation structure for an unbalanced rotating machine, with limited power supply, leading to interaction between the motor and the structure. This aspect is often not considered during usual design practice, although all real motors are, in this sense, non-ideal power sources. The considered mathematical model considers this system as non-ideal, subjected to the Sommerfeld effect, which may manifest close to foundation/machine’s resonances, with possible jumps from lower to higher frequency rotation regimes, no intermediate stable steady states in between. We also remarked that an additional property of (RNIS) with two degrees of from   can be observed when the adopted model was calibrated, a 2:1 internal resonance occurs between the frequencies of the second mode and the first mode of vibration. It is intended to demonstrate that the energy pumped into the system via the second mode, leads to the well know saturation phenomenon (the energy balance to the first mode, not directly excited, which starts to develop wide amplitudes, potentially dangerous and not predicted in theory. 

 

Other discussions addressed are the specific properties for various models considering transport mechanisms at MACRO and MEMS scales and their applications in engineering and science. The direction of future investigation is given by including a proposed mathematical model of energy harvesting, including non-linearities in the piezoelectric coupling and a non-ideal excitation force. So, we show through numerical simulations the non-linear dynamic responses that the collected power was influenced by the vibrations of the structure, as well as by the influence of the piezoelectric coupling.

 

 Another interesting aspect is that the increase in voltage in the DC motor led the system to produce power responses, which showed the high energy orbits in the resonance region. However, for regions above the resonance region, the Sommerfeld effect occurs, and the dynamics has a chaotic behavior. Thus, the energy captured over time decreases due to energy losses due to the interaction between the energy source and the structure. Keeping the captured energy constant over time is essential to enable the use of energy harvesting systems in real applications. To achieve this goal, we apply a control technique to stabilize the chaotic system in a stable periodic orbit, that is, the control kept the system in a stable condition. Thus, the aim of this project is to present a state of the art to better understand non-ideal systems using numerical, analytical methods and some experiments.

 

         By other hand, Timoshenko ‘s Beam Bending Model and the Sommerfeld Effect.Timoshenko’s beam bending model is an alternative to Euler-Bernoulli’s bending theory. In the latter, only the effects of the bending moment are considered, ignoring the acting shear forces. In Timoshenko’s theory, the effects of shear are also considered.If a beam is supporting a motor with limited power supply, which can lead to the so-called Sommerfeld Effect (stagnation of rotations at resonance and possible jumps), the Timoshenko hypothesis, although more complex, is preferable when the beam is relatively short in relation to the section dimensions, in which case the shear effect is appreciable. This is the case with short consoles .For a long beam, the Euler Bernoulli hypothesis is acceptable and simpler to apply.The adoption of any of these two hypotheses will of course reflect on the free vibration frequencies computation, specially upon the resonance frequency for which the Sommerfeld Effect may happen. As a more refined theory, Timoshenko’s beam bending theory should be a better approximation to the real behavior of such a system and is particularly better for high frequency excitations.

 

Finally, we say that this lecture is an overview of the literature dealing with the main properties of non-ideal vibrating systems. The analytical and numerical methods applied for analyzing such systems are shown. Practical examples of non-ideal systems are considered. The most common phenomenon for the systems is discussed (Sommerfeld effect, saturation phenomenon occurrence, and so on)  . The specific properties for various models are also discussed, considering Transportation mechanisms in MACRO  and MEMS scales and their applications to engineering and sciences. The direction of the future investigation is given. So, the aims of this lecture are to present a state of the art to better understand non ideal systems using numerical and some experiments.

 

KEYWORDS: Non ideal motor(RNIS), Mathematical Modeling, Nonlinear Systems, Control System, Chaotic Behavior.

Pierpaolo Belardinelli
Polytechnic University of Marche, Italy

Unconventional Stochastic Switching Events in Nonlinear Graphene Resonators

Nonlinear graphene resonators have recently been shown to be sensitive to thermal fluctuations close to room temperature. In this study, we investigate the nonlinear dynamics of a graphene nanodrum in relation to noise and while subject to an additional driving component far below the resonance frequency. The exceptional sensitivity of the graphene resonator leads to deviations from the conventional stochastic resonance scenario. These deviations are associated with alterations in the stable solutions and the paths of escape from metastable attractors. A theoretical model is employed to describe the intermittent occurrence of stochastic switching along with motion within a single quasiperiodic attractor. Our work thus reveals the significant effects of slow modulation on a nonlinear graphene resonator, which have important implications for sensing applications.

Yoshihiro Deguchi
Tokushima University, Japan

Digital Twin Advanced Control of Industrial Processes Integrating Laser Diagnostics and CFD

In this study, a digital twin advanced control method integrating laser diagnostics and computational fluid dynamics (CFD) was developed for the digital transformation (DX) of industrial processes. Computed Tomography-Tunable diode laser absorption spectroscopy(CT-TDLAS) and Laser Induced Breakdown spectroscopy(LIBS) monitoring systems were developed to monitor the concentration and temperature of industrial processes. CT-TDLAS is based on the CT method using absorption spectra of molecules such as H2O, CO2, CO, O2, NH3, and hydrocarbons and allows real-time measurement of temperature and concentration distributions in two and three dimensions. LIBS is an analytical detection technique based on atomic emission spectroscopy for determining elemental composition. The integration of laser diagnostics and CFD enables the prediction of nonlinear phenomena such as combustion, and the feasibility of digital twin advanced control has been developed and demonstrated using a CH4-NH3 swirl burner.

Mark Edelman
Yeshiva University, USA

Title: To be updated

To be updated.

Xilin Fu
Shandong Normal University, China

Title: To be updated

To be updated.

Igor Franović
Institute of Physics Belgrade, Serbia

Title: To be updated

To be updated.

Celso Grebogi
Member of the World Academy of Sciences
University of Aberdeen, UK

Title: To be updated

To be updated.

Markus Kirkilionis
University of Warwick, UK

Title: To be updated

To be updated.

Hiroshi Kori
University of Tokyo, Japan

Title: To be updated

To be updated.

Jürgen Kurths
Member of the Academia Europaea

Humboldt University Berlin, Germany

Title: To be updated

To be updated.

Nikolay V. Kuznetsov
Member of Russian Academy of Science
St.Petersburg State University, Russia

Title: To be updated

To be updated.

Xavier Leoncini
Aix-Marseille Université, France

Title: To be updated

To be updated.

Edson Denis Leonel
São Paulo State University, Rio Claro, Brazil

Title: To be updated

To be updated.

Zhihui Li
Beihang University, China

Numerical forecast and computational modeling of nonlinear mechanical behavior of structural response induced by strong aerodynamic thermal environment during re-entry of large-scale spacecraft

How to solve the hypersonic aerothermodynamics around large-scale spacecraft on expiration of service and nonlinear mechanical behavior in deformation failure and disintegration of metal (alloy) truss structure during falling crashing process from outer space to earth, is the key basis to resolve the numerical forecast for the falling area of the reentry crash and flight path after the completion of the spacecraft mission. To study aerodynamics of spacecraft reentry covering various flow regimes, a Gas-Kinetic Unified Algorithm (GKUA) has been presented by computable modeling of the collision integral of the Boltzmann equation over tens of years. On this basis, the rotational and vibrational energy modes are considered as the independent variables of the gas molecular velocity distribution function, a kind of Boltzmann model equation involving in internal energy excitation is presented by decomposing the collision term of the Boltzmann equation into elastic and inelastic collision terms. Then, the gas-kinetic numerical scheme is constructed to capture the time evolution of the discretized velocity distribution functions by developing the discrete velocity ordinate method and numerical quadrature technique. The unified algorithm of the Boltzmann model equation involving thermodynamics non-equilibrium effect is presented for the whole range of flow regimes. The gas-kinetic massive parallel computing strategy is developed to solve the hypersonic aerothermodynamics with the processor cores of 500~45,000 at least 80% parallel efficiency. To validate the accuracy of the GKUA, the hypersonic flows are simulated including the reentry Tiangong-1 spacecraft shape with the wide range of Knudsen numbers of 220~0.00005 by the comparison of the related results from the DSMC and N-S coupled methods, and the low-density tunnel experiment etc. The multi-body flow problems including two and three side-by-side cylinders and irregular bodies are simulated with different gap ratio in highly rarefied to near-continuum flow regimes to verify the accuracy and reliability of the GKUA in solving the multi-body aerothermodynamics for spacecraft falling disintegration, see Fig.1. To develop the computational modeling from the hypersonic flow field to the solid structure, a coupling mathematical model of transient heat conduction equation and thermo-elastic dynamic equation of materials is presented for falling and crashing problem during the unconventional reentry of un-controlling spacecraft, and then the finite-element algorithm of dynamic thermal-force coupling response is presented under strong aero-thermodynamic environment. The coupling computational technique of reentry aerodynamic environment and structural thermal response is developed, and the nonlinear mechanical behavior of structural response deformation of vertical plate and Tiangong-type vehicle was integrated to compute and verify under reentry aerodynamic environment. Then, the forecasting analysis platform of end-of-life large-scale spacecraft flying track is established on the basis of ballistic computation combined with reentry aerothermodynamics and deformation failure /disintegration. The accuracy and reliability of the large-scale parallel computing strategy and finite element algorithm are verified to reveal the thermal response deformation, and then, The integrated simulation platform has been applied to the uncontrolled falling of Tiangong-1 target spaceship, and the controlled reentry disintegration of the Tiangong-2 space laboratory. Figure 2 shows the forecast of flight trajectory and falling area of disintegrated wreckage and debris from the uncontrolled Tiangong-1 spacecraft falling with the comparison of the USA monitoring results afterwards from the map calibration of NASA’s post official website (www.space-Track.org) announcement in good agreement and compatibility. It is indicated from the falling reentry forecast that the uncontrolled Tiangong-1 will be disintegrated firstly at the range of 110-105km, secondly at 100-95km, specially, the main bearing-cone platform and trajectory controlling engines will be disintegrated at 83km-56km and so on. The present numerical forecasting platform obtained the scope of falling area distribution of longitudinal length 1200km and lateral width 100km from the first disintegration to debris falling to the ground. These results on the multiple disintegration, falling area distribution and trajectory calculation of coupled aerothermodynamics for the uncontrolled Tiangong-1 spacecraft affirm the accuracy and reliability of the unified modeling and typical computation of structural response and hypersonic aerothermodynamics for falling disintegration along ballistic trajectory with different flying height, Mach numbers covering various flow regimes from outer space to earth.

Keywords: Numerical forecast of nonlinear mechanical behavior of structural response; Tiangong-1 target vehicle; Aerothermodynamics covering various flow regimes; Boltzmann model equation in Thermodynamic non-equilibrium effect; Gas-kinetic unified algorithm; finite element algorithm of structural response deformation / destruction

Wei Lin
Fudan University, China

 

Title: To be updated

To be updated.

Albert C.J. Luo
Southern Illinois University, Edwardsville, USA

Limit Cycles and Homoclinic Networks in 2-dimensional Polynomial Systems

To be updated.

Elbert E. N. Macau
Federal University of Sao Paulo, Brazil

Title: To be updated

To be updated.

Sergey Meleshko
Suranaree University of Technology,

Thailand

Title: To be updated

To be updated.

Fuhong Min
Nanjing Normal University, China

Title: To be updated

To be updated.

Maaita Jamal-Odysseas
Aristotle University of Thessaloniki, Greece

Title: To be updated

To be updated

Pawel Olejnik
Lodz University of Technology, Poland

Title: To be updated

To be updated

Lev Ostrovsky
University of Colorado, Boulder, USA 

Damping and Amplification of Turbulence in the Ocean: Theory and Measurements
 

To be updated.

Vakhtang Putkaradze
University of Alberta, Canada

Title: To be updated

To be updated.

Victor Shrira
Keele University, UK

Title: To be updated

To be updated.

Carla Pinto
Instituto Superior de Engenharia do Porto, Portugal

Title: To be updated

To be updated.

Miguel AF Sanjuan
Member of Spanish Royal Academy of Sciences 

Rey Juan Carlos University in Madrid, Spain

Symphony of the Uncertainty in Three Movements

In this presentation, akin to a symphony in three movements, I will provide an overview of various concepts related to uncertainty and unpredictability in nonlinear dynamics. I will start from the topological concept of indecomposable continua to Wada basins. Then, I will continue with the Wada basins of the Hénon-Heiles Hamiltonian system, to finally culminate with the concept of basin entropy. Additionally, I will discuss recent advancements in using basin entropy for classifying basins, as well as for exploring bifurcations.

 

[1] J. Aguirre, R.L. Viana, and M. A. F. Sanjuán. Fractal structures in nonlinear dynamics. Reviews of Modern Physics 81, 333-386 (2009)
[2] A. Daza, A. Wagemakers, B. Georgeot, D. Guéry-Odelin, and M. A. F. Sanjuán. Basin entropy: a new tool to analyze uncertainty in dynamical systems. Scientific Reports 6, 31416 (2016)
[3] A. Daza, A. Wagemakers, and M. A. F. Sanjuán. Unpredictability and basin entropy. Europhysics Letters 141, 43001 (2023)
[4] A. Daza, A. Wagemakers, and M. A. F. Sanjuán. Classifying basins of attraction using the basin entropy. Chaos Solit. Fractals. 159, 112112 (2022).
[5] A. Wagemakers, A. Daza, and M. A. F. Sanjuán. Using the basin entropy to explore bifurcations. Chaos Solit. Fractals. 175, 113963 (2023).

Michael Small
The University of Western Australia, Australia

Title: To be updated

To be updated.

Haris Skokos
University of Cape Town, South Africa

Title: To be updated

To be updated.

Alexander Solynin
Texas Tech University, USA

Quadratic Differentials in Analysis and Theoretical Physics

To be updated.

Yury Stepanyants
University of Southern Queensland, Australia

Advanced theory of solitons, lumps, and ripplons in the cylindrical Kadomtsev−Petviashvili equation

We revise soliton and lump solutions described by the cylindrical Kadomtsev–Petviashvili (cKP) equation and construct new exact solutions relevant to the comparison with physical observations. In the first part of this study, we consider basically axisymmetric waves described by the cylindrical Kortweg–de Vries equation and analyse approximate and exact solutions to this equation. Then, we consider the stability of the axisymmetric solitons with respect to the azimuthal perturbations and suggest a criterion of soliton instability. The results of our numerical modelling confirm the suggested criterion and reveal lump emergence in the course of the development of the modulation instability of ring solitons in the unstable case. In the next part of this study, we present exact solutions to the cKP equation describing weakly nonlinear waves in media with positive dispersion subject to the modulation instability of solitons with respect to small azimuthal perturbations. By means of Zakharov–Shabat method, we derive exact solutions that describe two-dimensional solitary waves (lumps), lump chains, and their interactions. One of the obtained solutions describes the modulation instability of outgoing ring solitons and their disintegration onto a number of lumps. We also derive solutions describing decaying lumps and lump chains of a complex spatial structure – ripplons. Then, we study normal and anomalous (resonant) interactions of lump chains with each other and with ring solitons. The results obtained agree with the numerical data presented in the first part of this study.

In collaboration with

W. Hu1, Q. Guo2, and Zh. Zhang2

1School of Physics and Optoelectronic Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China;
2Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, South China Normal University, Guangzhou 510631, P. R. China.

C. Steve Suh
Texas A&M University, USA

Title: To be updated

To be updated.

Pierre E. Sullivan
University of Toronto, Canada

Reduced Order Modeling of Flow Over a Low Reynolds Number Airfoil

A single dielectric-barrier discharge plasma actuator is an active flow control (AFC) device that imparts momentum to the fluid through ion acceleration using electromagnetic forces and has been used to suppress flow separation. This presentation studies flow over an airfoil and how adding an SDBD actuator influences flow characteristics through numerical modeling. Using the spectral proper orthogonal decomposition and large-eddy simulation (LES), flow instabilities in the wake region are analyzed at their different temporal and spatial scales. These results are compared to resolvent analysis/ The objective of this study is to explore the viability of spectral proper orthogonal decomposition (SPOD) and resolvent analysis for separation control and correlate the decomposed flow modes to the different modes of actuation.

Jianqiao Sun
University of California, Merced, USA

Title: To be updated

To be updated.

Edgardo Ugalde
Instituto de Física – UASLP, Mexico

Title: To be updated

To be updated.

Luis Vázquez
Complutense University of Madrid, Spain

Title: To be updated

To be updated.

Dimitri Volchenkov
Texas Tech University, USA

Title: To be updated

To be updated.

Guo-Cheng Wu
Chongqing University of Posts and Telecommunications, China

Data-driven and Deep Learning of Fractional Difference Equations

This talk introduces several key problems in deep learning of fractional difference equations. A general fractional calculus is revisited and the function space is provided. By use of the time scale theory, Hadamard and Exponential discrete fractional calculus are defined and propositions are obtained. Finally, parameter estimation of fractional difference equations is investigated and its perspective is shown in deep learning.

Jiazhong Zhang
Xi’an Jiaotong University, China

LCSs-based Fine Functional Structures in Unsteady Fluid Flows

From viewpoint of dynamic system and topological physics, unsteady flow is one dissipative dynamic system, the initial study shows that there exist intrinsic spatiotemporal structures in complex unsteady flows, and their topology properties have significant influences on the flow performance. The Hyperbolic, Elliptic and Parabolic Lagrangian Coherent Structures (LCSs), with invariant spatiotemporal properties in a period, are introduced and developed to describe and analyze the complex flow structures in unsteady flows, and some numerical methods following nonlinear dynamics are given in capturing LCSs. Further, some fine functional structures, like energy sink, targeted energy transfer, are shown and studied in aeroacoustics and others. As the results, the methods based on complete intrinsic Lagrangian Coherent Structures could describe and analyze the flow structures and dynamics of complex unsteady flows quantitatively, and further control the flow with one new and accurate method.

Weinian Zhang
Sichuan University, China

Title: To be updated.

Weimou Zheng
Institute of Theoretical Physics, Chinese Academy of Sciences, China

Title: To be updated.

To be updated.

Zhigang Zheng
Huaqiao University
, China

Self-organization Dynamics of Chiral Swarmalators

Self-organized swarmings of interacting chiral oscillators (swarmalators) are studied. 
 
The mechanisms, forms, and manifestations of the emergence of various collective swarmed states are explored at both microscopic and macroscopic levels. These studies shed light on both theoretical understandings and potential applications of collective behaviors in complex systems.
 
This work is finacially supported by National Natural Science Foundation of CHINA No. 12375031.