{"title":"A novel two-dimensional D2Q9 cumulant-based lattice Boltzmann method: simulation and validation across multiple flow phenomena","authors":"Md. Mamun Molla","doi":"10.1016/j.cnsns.2025.109327","DOIUrl":"10.1016/j.cnsns.2025.109327","url":null,"abstract":"<div><div>This study presents a novel two-dimensional (2D) cumulant lattice Boltzmann method (CuLBM), known as D2Q9 CuLBM, which has been implemented using compute unit device architecture (CUDA) C/C++ to leverage graphics processing unit (GPU) computing for enhanced efficiency and performance. The cumulant-based lattice Boltzmann approach is a recent advancement in computational fluid dynamics (CFD) methods designed to offer improved stability and accuracy, particularly for simulating complex fluid flows. This work comprehensively describes the D2Q9 CuLBM formulation, focusing on its application to several benchmark and complex fluid flow cases. The well known validation tests include lid-driven cavity (LDC) flow and backward-facing step (BFS) flow, both frequently used in CFD to assess the accuracy and stability of numerical methods. Additionally, the model is evaluated on periodic double shear layer flow, a challenging problem for flow stability, Green–Taylor vortex and Kida–Pelz vortex flows and extended to shear-dependent non-Newtonian fluids, specifically those obeying power-law and Bingham models in the lid driven cavity, Couette and Poiseuille flows. These non-Newtonian cases are critical for capturing flows with complex rheological properties, demonstrating the versatility and accuracy of the D2Q9 CuLBM approach in handling a broad spectrum of fluid dynamics problems.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109327"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sahar Masoudian , Jason Sharples , Duncan Sutherland , Zlatko Jovanoski , James Hilton
{"title":"Modelling wildfire propagation using the stochastic level-set method","authors":"Sahar Masoudian , Jason Sharples , Duncan Sutherland , Zlatko Jovanoski , James Hilton","doi":"10.1016/j.cnsns.2025.109305","DOIUrl":"10.1016/j.cnsns.2025.109305","url":null,"abstract":"<div><div>The modelling of wildfire spread involves managing uncertainties from various sources, typically addressed through probabilistic rather than deterministic approaches. Natural random variability in the dynamics of the fire front can be directly captured by integrating stochastic noise into the fire front tracking model. To achieve this, a Gaussian noise is introduced into the level-set model using a stochastic level-set approach in the wildfire spread simulator “<span>spark</span>”. The incorporation of stochasticity into the fire spread model enables the simulation to capture variability in fire front growth.</div><div>The model is calibrated and validated by comparing the stochastic fire spread simulations to observed fire data. The developed model is also compared to a specific case of fire spread simulation created using the Wildland-Urban Fire Dynamic Simulator (<span>wfds</span>). This comparative analysis provides a conclusive evaluation, highlighting the performance and capabilities of the stochastic approach in capturing the uncertainties and complexities of fire behavior.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109305"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A new predefined-time fractional-order sliding mode synchronization control scheme for multi-motor systems","authors":"Jia-Meng Wu, Xin Huang, Cheng-Lin Liu","doi":"10.1016/j.cnsns.2025.109307","DOIUrl":"10.1016/j.cnsns.2025.109307","url":null,"abstract":"<div><div>This paper investigates the tracking and synchronization control of multi-motor systems and proposes a novel predefined-time fractional-order sliding mode control strategy. First, a novel simplified predefined-time stability condition is introduced, which alleviates the problem of parameter complexity in existing predefined-time stability theories and broadens their applicability. The validity of this condition is rigorously established through a Lyapunov-based analysis. Then, a fractional-order sliding mode observer is designed based on this stability condition. By integrating fractional-order calculus, the proposed observer increases flexibility and enhances the overall control performance compared to conventional observers. Furthermore, a fractional-order controller is developed by constructing a fractional-order sliding surface and a corresponding switching control law. The stability of the controller is further guaranteed by employing the Lyapunov function. Finally, simulation results are presented to verify the effectiveness of the proposed control strategy. These results highlight the advantages of the proposed controller, including rapid disturbance rejection, reduced chattering, and robust performance against unknown lumped disturbances.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109307"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimal tracking control for multi-player systems with irregular full-state constraints","authors":"Haoming Zou , Guoshan Zhang","doi":"10.1016/j.cnsns.2025.109295","DOIUrl":"10.1016/j.cnsns.2025.109295","url":null,"abstract":"<div><div>This paper investigates the optimal tracking control problem for multi-player systems with irregular full-state constraints utilizing state-dependent transformation technique and adaptive dynamic programming (ADP). Firstly, the connection function, switching and decision function, and barrier function are designed to transform irregular full-state constraints problem into the stabilization problem of barrier function. Besides, a similar idea is employed for the objective trajectory. Next, using the newly generated system and the objective trajectory, an augmented system is established to reformulate the tracking problem as an optimal regulation problem. Then, a dynamic event-triggered control scheme using ADP-based critic neural network is utilized to obtain the optimal solution while conserving communication and computational resources. It is proven that all signals of the closed-loop system are uniformly ultimately bounded. Finally, the proposed method for addressing the aforementioned issues is validated through numerical simulation examples.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109295"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145181256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yongfang Jin , Xingwu Liu , Lanfeng Hua , Shouming Zhong , Xingwen Liu
{"title":"The exponential stability criteria for second-order neural networks with time-varying mixed delays and actuator faults","authors":"Yongfang Jin , Xingwu Liu , Lanfeng Hua , Shouming Zhong , Xingwen Liu","doi":"10.1016/j.cnsns.2025.109320","DOIUrl":"10.1016/j.cnsns.2025.109320","url":null,"abstract":"<div><div>This paper addresses the global exponential stability (GES) problem of second-order neural networks (SNNs) with time-varying discrete and distributed delays (mixed delays) in the presence of unknown actuator failures. By designing delay-independent state-feedback fault-tolerant controllers and employing the Lyapunov functional method, algebraic criteria are established to guarantee GES of the concerned SNNs. In contrast to matrix inequalities conditions, these criteria are more convenient to verify. Specifically, the cases of fast- and slowly-varying delays are separately considered. Moreover, the original second-order delayed differential equations are investigated directly without any transformation to first-order ones. Finally, two simulation examples illustrate the obtained results.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109320"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Finite-time stability of 2D continuous switched nonlinear systems","authors":"Mengying Sun , Yongping Zhang , Dadong Tian","doi":"10.1016/j.cnsns.2025.109340","DOIUrl":"10.1016/j.cnsns.2025.109340","url":null,"abstract":"<div><div>The finite-time stability theory of 2D switched linear systems has been well developed, whereas few studies have focused on 2D switched nonlinear systems. In this paper, the finite-time stability of 2D continuous switched nonlinear systems is discussed. Firstly, by employing a common Lyapunov function method, the upper bounds on the times <span><math><msub><mi>T</mi><mn>1</mn></msub></math></span> and <span><math><msub><mi>T</mi><mn>2</mn></msub></math></span> required for the system to achieve finite-time stability are obtained. The results indicate that these upper bounds mainly depend on the system parameters and are independent of the switching signals. Sufficient conditions for the finite-time stability of 2D continuous switched nonlinear systems are further derived. Secondly, considering a wider range of situations, we introduce the multiple Lyapunov function methods, and derive the upper bounds on the times <span><math><msub><mi>T</mi><mn>1</mn></msub></math></span> and <span><math><msub><mi>T</mi><mn>2</mn></msub></math></span> again. The results reveal that, in addition to the system parameters, the upper bounds on the times <span><math><msub><mi>T</mi><mn>1</mn></msub></math></span> and <span><math><msub><mi>T</mi><mn>2</mn></msub></math></span> are also influenced by the switching signals. Additionally, a finite-time stabilization strategy is proposed based on the average dwell time method. We also extend the conclusions of finite-time stability to 2D continuous switched linear systems. Finally, two numerical examples are provided to illustrate the validity of our results.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109340"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cheng Wang, Jianxiang Xi, Le Wang, Zhicheng Yao, Jiuan Gao
{"title":"Output formation control and energy optimization strategies for singular swarm systems under budget constraint","authors":"Cheng Wang, Jianxiang Xi, Le Wang, Zhicheng Yao, Jiuan Gao","doi":"10.1016/j.cnsns.2025.109318","DOIUrl":"10.1016/j.cnsns.2025.109318","url":null,"abstract":"<div><div>This paper proposes an energy-optimized output formation control framework for singular swarm systems with dynamic communication topologies, addressing the critical challenge of coordinating energy-constrained multi-agent networks. By integrating constrained equivalent transformation and observability decomposition, we develop a dynamic output feedback protocol featuring a state-dependent formation mapping mechanism. The framework establishes sufficient conditions for leaderless time-varying output formation realization under topology switching, while providing explicit energy feasibility criteria and formation construction constraints. Crucially, a linear matrix inequality-based two-stage optimization method is introduced to determine gain matrices, and the explicit expression of the output formation center function is analytically determined to characterize the swarm’s global motion. Numerical simulation demonstrates the theoretical validity, in which an time-varying regular-octagon output formation along circular trajectories is achieved under the constraint of a given energy budget.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109318"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaohong Cheng , Shuang Liu , Shaomeng Gu , Wenbo Wang
{"title":"Adaptive fixed-time tracking control based on a novel command filter for uncertain nonlinear systems with asymmetric time-varying constraints","authors":"Xiaohong Cheng , Shuang Liu , Shaomeng Gu , Wenbo Wang","doi":"10.1016/j.cnsns.2025.109312","DOIUrl":"10.1016/j.cnsns.2025.109312","url":null,"abstract":"<div><div>In this paper, an adaptive fixed-time tracking control method is proposed for uncertain nonlinear systems under asymmetric time-varying constraints to enhance control performance and stability, which includes a novel command filter, a series of newly designed adaptive laws, and a fixed-time controller. First, an improved fixed-time command filtering framework incorporating dynamic error compensation is proposed to effectively address the “complexity explosion” problem caused by the backstepping technology. Second, novel adaptive laws are designed based on radial basis function neural networks (RBFNN) to handle the uncertain nonlinear term and disturbance. Subsequently, based on the time-varying asymmetric barrier Lyapunov function (TABLF), a fixed-time controller is designed to track the reference signal, and all system states can be remained within asymmetric time-varying constraints. Finally, two simulation examples are presented to demonstrate the effectiveness of the proposed control method.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109312"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bifurcation sequences in the secular 3D planetary 3-Body problem: a geometric approach","authors":"Rita Mastroianni , Antonella Marchesiello , Christos Efthymiopoulos , Giuseppe Pucacco","doi":"10.1016/j.cnsns.2025.109324","DOIUrl":"10.1016/j.cnsns.2025.109324","url":null,"abstract":"<div><div>We implement the geometric method proposed in [14, 17, <span><span>21</span></span>] to analytically predict the sequence of bifurcations leading to a change of stability and/or the appearance of new periodic orbits in the secular 3D planetary three body problem. Stemming from the analysis in [1], we examine various normal form models as regards the extent to which they lead to a phase space dynamics qualitatively similar as that in the complete system. For fixed total angular momentum, the phase space in Hopf variables is the 3D sphere, and the complete sequence of bifurcations of new periodic orbits can be recovered through formulas yielding the tangencies or degenerate intersections between the sphere and the surfaces of a constant second integral of motion of the normal form flow. In particular, we find the critical values of the second integral giving rise to pitchfork and saddle-node bifurcations of new periodic orbits in the system. This analysis renders possible to predict the most important structural changes in the phase space, as well as the emergence of new possible stable periodic planetary orbital configurations which can take place as the mutual inclination between the two planets is allowed to increase.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109324"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Event-triggered impulsive control for nonlinear impulsive disturbed systems with applications","authors":"Qi Fang , Xiaodi Li","doi":"10.1016/j.cnsns.2025.109292","DOIUrl":"10.1016/j.cnsns.2025.109292","url":null,"abstract":"<div><div>This paper researches the Lyapunov stability of nonlinear impulsive disturbed systems in the framework of anti-impulse disturbance event-triggered impulsive control (<em>ETIC</em>), where impulsive control instants are determined by the designed event-triggered mechanism (<em>ETM</em>) with intermittent detection. Different from the existing event-triggered mechanisms, a novel <em>ETM</em> which utilizes impulsive interference information is proposed by which the impulsive controller is always accurately activated once between two adjacent impulsive disturbances, thus the divergent dynamics caused by impulsive disturbances can be suppressed promptly and effectively. Moreover, some sufficient conditions are derived to eliminate Zeno behavior and to achieve asymptotical stability of nonlinear systems subject to impulsive disturbances under <em>ETIC</em>. Then, the theoretical results are applied to chaotic systems with impulsive disturbances, and some linear matrix inequalities are established to realize the synchronization of chaotic systems. Finally, two numeral simulations are given to demonstrate the feasibility and superiority of the proposed results.</div></div>","PeriodicalId":50658,"journal":{"name":"Communications in Nonlinear Science and Numerical Simulation","volume":"152 ","pages":"Article 109292"},"PeriodicalIF":3.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}