Latest open access articles published in Journal of Complex and Multiphysics Engineering Systems at https://www.acadlore.com/journals/JCMES https://www.acadlore.com/journals/JCMES Acadlore en Creative Commons Attribution(CC - BY) JCMES support@acadlore.com https://www.acadlore.com/article/JCMES/2026_1_2/jcmes010204 Forest residues generated from logging operations, forest maintenance, and wood-processing activities represent an increasingly important secondary biomass resource for sustainable material engineering. The heterogene-ous composition of these residues, together with their high lignocellulosic content, creates significant opportunities for their integration into wood-based composites and bio-derived adhesive systems. However, variability in species, morphology, moisture sensitivity, and chemical composition still limits their large-scale and standardized industrial utilization. This review investigates the valorization pathways of forest management residues within engineered wood-based material systems, with particular emphasis on wood–plastic composites, fiberboards, veneer-based products, and bio-adhesives derived from lignin and tannin fractions. The reviewed studies were identified through a structured survey of recent scientific literature focusing on the processing, classification, physicochemical characteristics, and engineering applications of forest biomass residues. Different utilization strategies were examined according to the geometrical form of the biomass, including fibers, particles, powders, and chemically extracted constituents used for adhesive formulation. The reviewed literature showed that forest residues were successfully incorporated into thermoplastic and thermosetting composite systems, where they contributed to stiffness enhancement, material lightweighting, and partial substitution of petroleum-derived constituents. Lignin- and tannin-based bio-adhesives also demonstrated promising potential for reducing formaldehyde dependence in wood panel manufacturing, although challenges related to reactivity, water resistance, and compositional variability remained significant. The findings further indicated that hybrid biomass systems, adhesive-free densified boards, and integrated biorefinery approaches have progressively expanded the technological possibilities for circular biomass utilization. The study demonstrates that forest residues can serve as multifunctional feedstocks for sustainable wood-based engineering materials when supported by appropriate material selection, traceability, and process integration strategies. The review also provides critical insights into the current limitations, scalability challenges, and future research directions associated with the transition toward low-emission and circular lignocellulosic material systems. 04-16-2026 <![CDATA[ <p>Forest residues generated from logging operations, forest maintenance, and wood-processing activities represent an increasingly important secondary biomass resource for sustainable material engineering. The heterogene-ous composition of these residues, together with their high lignocellulosic content, creates significant opportunities for their integration into wood-based composites and bio-derived adhesive systems. However, variability in species, morphology, moisture sensitivity, and chemical composition still limits their large-scale and standardized industrial utilization. This review investigates the valorization pathways of forest management residues within engineered wood-based material systems, with particular emphasis on wood–plastic composites, fiberboards, veneer-based products, and bio-adhesives derived from lignin and tannin fractions. The reviewed studies were identified through a structured survey of recent scientific literature focusing on the processing, classification, physicochemical characteristics, and engineering applications of forest biomass residues. Different utilization strategies were examined according to the geometrical form of the biomass, including fibers, particles, powders, and chemically extracted constituents used for adhesive formulation. The reviewed literature showed that forest residues were successfully incorporated into thermoplastic and thermosetting composite systems, where they contributed to stiffness enhancement, material lightweighting, and partial substitution of petroleum-derived constituents. Lignin- and tannin-based bio-adhesives also demonstrated promising potential for reducing formaldehyde dependence in wood panel manufacturing, although challenges related to reactivity, water resistance, and compositional variability remained significant. The findings further indicated that hybrid biomass systems, adhesive-free densified boards, and integrated biorefinery approaches have progressively expanded the technological possibilities for circular biomass utilization. The study demonstrates that forest residues can serve as multifunctional feedstocks for sustainable wood-based engineering materials when supported by appropriate material selection, traceability, and process integration strategies. The review also provides critical insights into the current limitations, scalability challenges, and future research directions associated with the transition toward low-emission and circular lignocellulosic material systems.</p> ]]> Forest Management Residues for Engineered Wood-Based Composites and Bio-Adhesive Systems: A Critical Review on Material Valorization and Circular Biomass Integration serena gabrielli ayazhan yegissinova simone campanelli cristiano fragassa carlo santulli doi: 10.56578/jcmes010204 Journal of Complex and Multiphysics Engineering Systems 04-16-2026 Journal of Complex and Multiphysics Engineering Systems 04-16-2026 2026 1 2 Article 160 10.56578/jcmes010204 https://www.acadlore.com/article/JCMES/2026_1_2/jcmes010204 https://www.acadlore.com/article/JCMES/2026_1_2/jcmes010203 Friction stir welding of thin AA2024-T4 sheets is characterized by complex thermo–mechanical interactions arising from rapid heat dissipation, steep thermal gradients, and severe plastic deformation. In the present study, a coupled thermo–mechanical finite element model based on the coupled Eulerian–Lagrangian approach was developed in ABAQUS/Explicit to investigate material flow behavior, temperature evolution, strain distribution, and mechanical performance during friction stir welding of 2 mm-thick AA2024-T4 sheets. A systematic experimental campaign was conducted using rotational speeds ranging from 1000 to 1600 rpm and traverse speeds between 100 and 300 mm/min, corresponding to rotational-to-traverse speed ratios (ω/v) of 3.33–16.0 mm⁻¹. Thermal histories acquired using embedded K-type thermocouples and mechanical characterization through tensile and hardness testing were employed for model validation. Excellent agreement was achieved between numerical predictions and experimental measurements, with deviations limited to 3.2% for peak temperature and 1.5% for ultimate tensile strength, while coefficients of determination (R²) exceeding 0.985 were obtained for all validated responses. The thermo–mechanical simulations revealed pronounced localization of equivalent plastic strain within the stir zone and demonstrated that the spatial distribution of strain and heat generation strongly governed hardness evolution and joint performance. An optimum welding condition was identified at ω = 1400 rpm and v = 300 mm/min, corresponding to an ω/v ratio of 4.67 mm⁻¹, under which a maximum joint efficiency of 88% was achieved. Furthermore, the developed framework enabled quantitative correlation between process parameters, thermo–mechanical fields, and resulting mechanical properties, thereby providing mechanistic insight into defect suppression and weld quality enhancement in thin-sheet friction stir welding. The validated numerical framework is expected to serve as a reliable predictive tool for process optimization and performance assessment of high-strength aerospace aluminum alloys subjected to friction stir welding. 04-11-2026 <![CDATA[ <p>Friction stir welding of thin AA2024-T4 sheets is characterized by complex thermo–mechanical interactions arising from rapid heat dissipation, steep thermal gradients, and severe plastic deformation. In the present study, a coupled thermo–mechanical finite element model based on the coupled Eulerian–Lagrangian approach was developed in ABAQUS/Explicit to investigate material flow behavior, temperature evolution, strain distribution, and mechanical performance during friction stir welding of 2 mm-thick AA2024-T4 sheets. A systematic experimental campaign was conducted using rotational speeds ranging from 1000 to 1600 rpm and traverse speeds between 100 and 300 mm/min, corresponding to rotational-to-traverse speed ratios (<em>ω</em>/<em>v</em>) of 3.33–16.0 mm⁻¹. Thermal histories acquired using embedded K-type thermocouples and mechanical characterization through tensile and hardness testing were employed for model validation. Excellent agreement was achieved between numerical predictions and experimental measurements, with deviations limited to 3.2% for peak temperature and 1.5% for ultimate tensile strength, while coefficients of determination (<em>R</em>²) exceeding 0.985 were obtained for all validated responses. The thermo–mechanical simulations revealed pronounced localization of equivalent plastic strain within the stir zone and demonstrated that the spatial distribution of strain and heat generation strongly governed hardness evolution and joint performance. An optimum welding condition was identified at <em>ω</em> = 1400 rpm and <em>v</em> = 300 mm/min, corresponding to an <em>ω</em>/<em>v</em> ratio of 4.67 mm⁻¹, under which a maximum joint efficiency of 88% was achieved. Furthermore, the developed framework enabled quantitative correlation between process parameters, thermo–mechanical fields, and resulting mechanical properties, thereby providing mechanistic insight into defect suppression and weld quality enhancement in thin-sheet friction stir welding. The validated numerical framework is expected to serve as a reliable predictive tool for process optimization and performance assessment of high-strength aerospace aluminum alloys subjected to friction stir welding.</p> ]]> Coupled Thermo–Mechanical Modeling and Experimental Validation of Friction Stir Welding in Thin AA2024-T4 Sheets anton alekseevich naumov oleg vladislavovich panchenko seyed vahid safi seyed majid safi aleksei aleksandrovich boychenko doi: 10.56578/jcmes010203 Journal of Complex and Multiphysics Engineering Systems 04-11-2026 Journal of Complex and Multiphysics Engineering Systems 04-11-2026 2026 1 2 Article 148 10.56578/jcmes010203 https://www.acadlore.com/article/JCMES/2026_1_2/jcmes010203 https://www.acadlore.com/article/JCMES/2026_1_2/jcmes010202 Accurate damage identification in planar truss structures is essential for ensuring structural reliability, operational safety, and long-term serviceability in complex multiphysics environments. In this study, a structural damage identification framework was developed by integrating metaheuristic optimization algorithms with the finite element method. The particle swarm optimization (PSO) and the genetic algorithm were employed to identify both the location and severity of structural damage. The natural frequencies of the structure were adopted as objective indicators. The optimization process was designed to minimize the difference between measured and computed frequency responses, thereby enabling the precise localization and quantification of damage in individual elements. Furthermore, the applicability of the developed framework to structural systems operating under coupled multiphysics effects was emphasized, thereby enhancing its practical relevance for real-world engineering applications. The proposed approach provides an effective and computationally efficient strategy for structural health monitoring and damage assessment of planar truss systems, with significant potential for integration into intelligent maintenance and reliability management frameworks. 04-08-2026 <![CDATA[ Accurate damage identification in planar truss structures is essential for ensuring structural reliability, operational safety, and long-term serviceability in complex multiphysics environments. In this study, a structural damage identification framework was developed by integrating metaheuristic optimization algorithms with the finite element method. The particle swarm optimization (PSO) and the genetic algorithm were employed to identify both the location and severity of structural damage. The natural frequencies of the structure were adopted as objective indicators. The optimization process was designed to minimize the difference between measured and computed frequency responses, thereby enabling the precise localization and quantification of damage in individual elements. Furthermore, the applicability of the developed framework to structural systems operating under coupled multiphysics effects was emphasized, thereby enhancing its practical relevance for real-world engineering applications. The proposed approach provides an effective and computationally efficient strategy for structural health monitoring and damage assessment of planar truss systems, with significant potential for integration into intelligent maintenance and reliability management frameworks. ]]> Identification of Damage in Planar Truss Structures Within a Multiphysics Framework Using Metaheuristic Optimization Algorithms hoang lan ton-that doi: 10.56578/jcmes010202 Journal of Complex and Multiphysics Engineering Systems 04-08-2026 Journal of Complex and Multiphysics Engineering Systems 04-08-2026 2026 1 2 Article 138 10.56578/jcmes010202 https://www.acadlore.com/article/JCMES/2026_1_2/jcmes010202 https://www.acadlore.com/article/JCMES/2026_1_2/jcmes010201 The thermo-mechanical response of power module heat sinks under cyclic loading conditions plays a critical role in determining the structural reliability of automotive electronic systems. This study investigates the deformation behaviour of a dual-plate aluminium heat sink subjected to combined thermal and power cycling representative of service conditions. An experimental approach based on distributed resistive strain gauges was employed to capture local strain evolution at selected locations across the structure. A controlled zero-balancing procedure was implemented to isolate the contribution of assembly-induced preload from thermally driven deformation. The instrumented module was first exposed to climatic chamber cycles in the range -40 $^\circ \text{C}$ to 75 $^\circ\text{C}$, followed by power thermal cycling endurance tests designed to reproduce operational loading sequences. The measurements reveal a stable and repeatable strain response governed by the interaction between non-uniform thermal expansion and discrete mechanical constraints. The heat sink exhibits compressive states at low temperature and progressively transitions to tensile deformation as temperature increases, with limited hysteresis during cyclic loading. Spatial variations in strain are observed across the structure, reflecting the influence of fastening conditions, thermal gradients, and structural coupling within the assembly. A simplified finite element representation is used to support the interpretation of the experimental observations and to provide qualitative insight into the deformation pattern and constraint effects. The results show that the dominant contribution to the overall strain field originates from assembly preload, while thermal cycling induces a consistent and largely elastic response without evidence of critical deformation anomalies under the investigated conditions. The study provides an experimentally grounded assessment of thermo-mechanical behaviour in power module heat sinks and offers practical guidance for measurement strategies and structural evaluation under coupled thermal and operational loading. 04-02-2026 <![CDATA[ <p>The thermo-mechanical response of power module heat sinks under cyclic loading conditions plays a critical role in determining the structural reliability of automotive electronic systems. This study investigates the deformation behaviour of a dual-plate aluminium heat sink subjected to combined thermal and power cycling representative of service conditions. An experimental approach based on distributed resistive strain gauges was employed to capture local strain evolution at selected locations across the structure. A controlled zero-balancing procedure was implemented to isolate the contribution of assembly-induced preload from thermally driven deformation. The instrumented module was first exposed to climatic chamber cycles in the range -40 $^\circ \text{C}$ to 75 $^\circ\text{C}$, followed by power thermal cycling endurance tests designed to reproduce operational loading sequences. The measurements reveal a stable and repeatable strain response governed by the interaction between non-uniform thermal expansion and discrete mechanical constraints. The heat sink exhibits compressive states at low temperature and progressively transitions to tensile deformation as temperature increases, with limited hysteresis during cyclic loading. Spatial variations in strain are observed across the structure, reflecting the influence of fastening conditions, thermal gradients, and structural coupling within the assembly. A simplified finite element representation is used to support the interpretation of the experimental observations and to provide qualitative insight into the deformation pattern and constraint effects. The results show that the dominant contribution to the overall strain field originates from assembly preload, while thermal cycling induces a consistent and largely elastic response without evidence of critical deformation anomalies under the investigated conditions. The study provides an experimentally grounded assessment of thermo-mechanical behaviour in power module heat sinks and offers practical guidance for measurement strategies and structural evaluation under coupled thermal and operational loading.</p> ]]> Thermo-Mechanical Response of an Automotive Power Module Heat Sink under Combined Thermal and Power Cycling cristiano fragassa salvatore massimo marco arru ana pavlovic doi: 10.56578/jcmes010201 Journal of Complex and Multiphysics Engineering Systems 04-02-2026 Journal of Complex and Multiphysics Engineering Systems 04-02-2026 2026 1 2 Article 122 10.56578/jcmes010201 https://www.acadlore.com/article/JCMES/2026_1_2/jcmes010201 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010107 Local failure in cellular beams is strongly influenced by stress redistribution within the web-post region, yet bending-dominated mechanisms associated with closely spaced openings remain insufficiently addressed in current design provisions. This study examines the limit load corresponding to web-post bending failure using a three-dimensional Finite Element (FE) framework, with particular attention to structural members employed in integrated systems where service openings are required. The numerical model is first validated against available experimental and computational results to ensure accurate representation of both global response and local stress transfer. A parametric study involving 100 models is then carried out by varying section size, slenderness ratio, and opening ratio. The limit load is defined by the formation of a continuous yield path across the web-post ligament. The results show that bending-dominated web-post failure develops as a progressive mechanism controlled by the combined action of normal stress and shear transfer. This mode consistently precedes other local mechanisms, including web-post shear failure and Vierendeel action, and therefore governs the load-carrying capacity. Comparisons with ANSI/AISC 360-16 indicate that the current provisions underestimate the limit load by an average of 68.85%, with larger discrepancies observed for beams with lower slenderness ratios, smaller opening ratios, and larger section sizes. The findings highlight the need to explicitly consider this failure mode in design and provide a clearer basis for assessing the local resistance of cellular beams used in structural systems where mechanical performance must be reconciled with service integration requirements. 03-30-2026 <![CDATA[ <p>Local failure in cellular beams is strongly influenced by stress redistribution within the web-post region, yet bending-dominated mechanisms associated with closely spaced openings remain insufficiently addressed in current design provisions. This study examines the limit load corresponding to web-post bending failure using a three-dimensional Finite Element (FE) framework, with particular attention to structural members employed in integrated systems where service openings are required. The numerical model is first validated against available experimental and computational results to ensure accurate representation of both global response and local stress transfer. A parametric study involving 100 models is then carried out by varying section size, slenderness ratio, and opening ratio. The limit load is defined by the formation of a continuous yield path across the web-post ligament. The results show that bending-dominated web-post failure develops as a progressive mechanism controlled by the combined action of normal stress and shear transfer. This mode consistently precedes other local mechanisms, including web-post shear failure and Vierendeel action, and therefore governs the load-carrying capacity. Comparisons with ANSI/AISC 360-16 indicate that the current provisions underestimate the limit load by an average of 68.85%, with larger discrepancies observed for beams with lower slenderness ratios, smaller opening ratios, and larger section sizes. The findings highlight the need to explicitly consider this failure mode in design and provide a clearer basis for assessing the local resistance of cellular beams used in structural systems where mechanical performance must be reconciled with service integration requirements.</p> ]]> Limit Load of Cellular Beams Governed by Web-Post Bending Failure in Integrated Structural Systems moe pwint phyu nonthawat inkiaesai warayut tasit pongphet yanshai worathep sae-long sutham arun suchart limkatanyu doi: 10.56578/jcmes010107 Journal of Complex and Multiphysics Engineering Systems 03-30-2026 Journal of Complex and Multiphysics Engineering Systems 03-30-2026 2026 1 1 Article 110 10.56578/jcmes010107 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010107 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010106 Cold thermal energy storage systems based on phase change materials (PCMs) play an important role in improving the efficiency of refrigeration and cooling applications, yet their performance is often limited by the low thermal conductivity of the storage medium. This study examines the solidification process in a PCM-based system enhanced by a porous metal foam structure and a ternary hybrid nanofluid. The configuration combines a wavy-walled container with internal fins, where the thermal response is governed by the interaction between modified material properties and the conductive network formed within the porous medium. A transient numerical model is developed using a Galerkin weighted residual formulation with adaptive mesh refinement to resolve the evolution of the solidification front. Owing to the limited fluid motion during freezing, the analysis focuses on conduction-driven transport while retaining the influence of material heterogeneity on heat transfer. The numerical implementation is validated against benchmark results reported in the literature, showing good agreement. The results indicate that the addition of ternary nanoparticles ($\mathrm{Al}_2 \mathrm{O}_3-\mathrm{TiO}_2-\mathrm{Ag}$) leads to a moderate increase in the solidification rate, reducing the freezing time by approximately 13.14% through enhancement of effective thermal conductivity. In contrast, the introduction of metal foam significantly alters the heat transfer pathway within the domain, shortening the freezing duration by more than 80% due to the formation of an extended conductive structure. When both enhancement strategies are applied simultaneously, a further reduction in freezing time is observed, indicating a combined effect of material modification and structural conduction. The findings provide quantitative insight into the relative roles of nanoparticle dispersion and porous media in conduction-dominated phase change processes and offer guidance for the design of efficient cold thermal energy storage systems. 03-28-2026 <![CDATA[ <p>Cold thermal energy storage systems based on phase change materials (PCMs) play an important role in improving the efficiency of refrigeration and cooling applications, yet their performance is often limited by the low thermal conductivity of the storage medium. This study examines the solidification process in a PCM-based system enhanced by a porous metal foam structure and a ternary hybrid nanofluid. The configuration combines a wavy-walled container with internal fins, where the thermal response is governed by the interaction between modified material properties and the conductive network formed within the porous medium. A transient numerical model is developed using a Galerkin weighted residual formulation with adaptive mesh refinement to resolve the evolution of the solidification front. Owing to the limited fluid motion during freezing, the analysis focuses on conduction-driven transport while retaining the influence of material heterogeneity on heat transfer. The numerical implementation is validated against benchmark results reported in the literature, showing good agreement. The results indicate that the addition of ternary nanoparticles ($\mathrm{Al}_2 \mathrm{O}_3-\mathrm{TiO}_2-\mathrm{Ag}$) leads to a moderate increase in the solidification rate, reducing the freezing time by approximately 13.14% through enhancement of effective thermal conductivity. In contrast, the introduction of metal foam significantly alters the heat transfer pathway within the domain, shortening the freezing duration by more than 80% due to the formation of an extended conductive structure. When both enhancement strategies are applied simultaneously, a further reduction in freezing time is observed, indicating a combined effect of material modification and structural conduction. The findings provide quantitative insight into the relative roles of nanoparticle dispersion and porous media in conduction-dominated phase change processes and offer guidance for the design of efficient cold thermal energy storage systems.</p> ]]> Coupled Heat Transfer and Phase Change in a Porous Nanofluid-Enhanced Cold Thermal Energy Storage System: An Adaptive Mesh-Based Numerical Study ahmad shafee doi: 10.56578/jcmes010106 Journal of Complex and Multiphysics Engineering Systems 03-28-2026 Journal of Complex and Multiphysics Engineering Systems 03-28-2026 2026 1 1 Article 98 10.56578/jcmes010106 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010106 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010105 Efficient thermal management in electrically conducting fluids is critically required in advanced engineering systems, including power generation, electronic cooling, and nuclear reactor technologies, where strong magnetic fields significantly influence transport phenomena. In the present study, steady, incompressible flow of a hybrid nanofluid over a porous stretching surface was systematically investigated under the combined effects of Hall current, thermal radiation, and a spatially varying heat source. The hybrid nanofluid was formulated by dispersing tricalcium phosphate (Ca$_3$(PO$_4$)$_2$) and molybdenum disulfide (MoS$_2$) nanoparticles in water. The governing nonlinear partial differential equations were transformed into a system of coupled ordinary differential equations through similarity transformations, and numerical solutions were obtained using a fourth-order Runge–Kutta method coupled with a shooting algorithm. To further optimize the thermal transport characteristics, the Taguchi optimization technique with an L$_{16}$ orthogonal array was employed to evaluate the relative significance of key parameters and to identify optimal parametric combinations. The results reveal that the hybrid nanofluid exhibits superior thermal performance compared with conventional nanofluids. These findings provide valuable insights for the design and optimization of multiphysics thermal systems involving magnetohydrodynamic flows and hybrid nanofluids, thereby contributing to the development of high-efficiency thermal management technologies. 03-26-2026 <![CDATA[ <p>Efficient thermal management in electrically conducting fluids is critically required in advanced engineering systems, including power generation, electronic cooling, and nuclear reactor technologies, where strong magnetic fields significantly influence transport phenomena. In the present study, steady, incompressible flow of a hybrid nanofluid over a porous stretching surface was systematically investigated under the combined effects of Hall current, thermal radiation, and a spatially varying heat source. The hybrid nanofluid was formulated by dispersing tricalcium phosphate (Ca$_3$(PO$_4$)$_2$) and molybdenum disulfide (MoS$_2$) nanoparticles in water. The governing nonlinear partial differential equations were transformed into a system of coupled ordinary differential equations through similarity transformations, and numerical solutions were obtained using a fourth-order Runge–Kutta method coupled with a shooting algorithm. To further optimize the thermal transport characteristics, the Taguchi optimization technique with an L$_{16}$ orthogonal array was employed to evaluate the relative significance of key parameters and to identify optimal parametric combinations. The results reveal that the hybrid nanofluid exhibits superior thermal performance compared with conventional nanofluids. These findings provide valuable insights for the design and optimization of multiphysics thermal systems involving magnetohydrodynamic flows and hybrid nanofluids, thereby contributing to the development of high-efficiency thermal management technologies.</p> ]]> Hall-Effect-Modulated Thermal Transport Enhancement in Hybrid Nanofluid Flow over a Stretching Surface Using Taguchi Optimization ram prakash sharma bimal kumar barik sriram praharaj v. vinay kumar abhishek sharma doi: 10.56578/jcmes010105 Journal of Complex and Multiphysics Engineering Systems 03-26-2026 Journal of Complex and Multiphysics Engineering Systems 03-26-2026 2026 1 1 Article 82 10.56578/jcmes010105 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010105 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010104 Phase-change thermal energy storage systems are widely employed to regulate heat transfer under transient operating conditions. This study investigates the coupled effects of porous media, thermal radiation, and hybrid nanofluids on the solidification behaviour of a phase change material, treating the system as an interacting multiphysics heat transfer problem. A numerical framework based on the Galerkin method with adaptive meshing is used to analyse solidification within enclosures of different geometries. Hybrid nanoparticles are introduced to modify the effective thermal properties of the base material, while porous structures and radiative effects are incorporated to influence the dominant heat transfer mechanisms during phase transition. The results indicate that the addition of nanoparticles alone reduces the total freezing time by approximately 7.81% in the absence of porous media and radiation. The inclusion of radiative effects further accelerates the process, with reductions of up to 32.62% observed in non-porous configurations. When porous media, radiation, and nanoparticle enhancement are combined, additional improvements in solidification rate are obtained, reflecting the interaction among the governing transport processes. The findings show that solidification performance in phase-change systems is controlled by the interplay of conduction, radiation, and porous transport, and that coordinated modification of these mechanisms provides an effective route to improving thermal energy storage efficiency. 03-25-2026 <![CDATA[ <p>Phase-change thermal energy storage systems are widely employed to regulate heat transfer under transient operating conditions. This study investigates the coupled effects of porous media, thermal radiation, and hybrid nanofluids on the solidification behaviour of a phase change material, treating the system as an interacting multiphysics heat transfer problem. A numerical framework based on the Galerkin method with adaptive meshing is used to analyse solidification within enclosures of different geometries. Hybrid nanoparticles are introduced to modify the effective thermal properties of the base material, while porous structures and radiative effects are incorporated to influence the dominant heat transfer mechanisms during phase transition. The results indicate that the addition of nanoparticles alone reduces the total freezing time by approximately 7.81% in the absence of porous media and radiation. The inclusion of radiative effects further accelerates the process, with reductions of up to 32.62% observed in non-porous configurations. When porous media, radiation, and nanoparticle enhancement are combined, additional improvements in solidification rate are obtained, reflecting the interaction among the governing transport processes. The findings show that solidification performance in phase-change systems is controlled by the interplay of conduction, radiation, and porous transport, and that coordinated modification of these mechanisms provides an effective route to improving thermal energy storage efficiency.</p> ]]> Coupled Thermo-Physical Processes in Porous Phase-Change Energy Storage Systems with Hybrid Nanofluids mina mirparizi doi: 10.56578/jcmes010104 Journal of Complex and Multiphysics Engineering Systems 03-25-2026 Journal of Complex and Multiphysics Engineering Systems 03-25-2026 2026 1 1 Article 70 10.56578/jcmes010104 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010104 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010103 Accurate prediction of acoustic propagation in salt cavern gas storage remains challenging due to the strong coupling between temperature and concentration fields in high-salinity environments. A multiphysics modelling framework is established by integrating piezoelectric, acoustic, and solid mechanics interactions with a temperature-dependent sound velocity formulation that accounts for concentration effects. The model is implemented in an axisymmetric configuration and evaluated under representative thermal and salinity conditions. The results demonstrate a pronounced nonlinear response of acoustic propagation to coupled temperature–concentration effects. Under elevated temperature and near-saturated brine conditions, a plateau-like behaviour in acoustic energy dissipation is observed, where further temperature increase leads to limited additional attenuation. This behaviour is governed by the competition between impedance matching efficiency and sound speed variation. Quantitative analysis indicates that reliance on room-temperature calibration may introduce systematic deviations of approximately 9% under high-temperature conditions. The study provides a physically grounded interpretation of acoustic behaviour under coupled-field conditions and offers a basis for improving the reliability of sonar-based detection in salt cavern environments. The proposed framework further contributes to the modelling of thermo-acoustic interactions in complex subsurface energy systems. 03-23-2026 <![CDATA[ <p>Accurate prediction of acoustic propagation in salt cavern gas storage remains challenging due to the strong coupling between temperature and concentration fields in high-salinity environments. A multiphysics modelling framework is established by integrating piezoelectric, acoustic, and solid mechanics interactions with a temperature-dependent sound velocity formulation that accounts for concentration effects. The model is implemented in an axisymmetric configuration and evaluated under representative thermal and salinity conditions. The results demonstrate a pronounced nonlinear response of acoustic propagation to coupled temperature–concentration effects. Under elevated temperature and near-saturated brine conditions, a plateau-like behaviour in acoustic energy dissipation is observed, where further temperature increase leads to limited additional attenuation. This behaviour is governed by the competition between impedance matching efficiency and sound speed variation. Quantitative analysis indicates that reliance on room-temperature calibration may introduce systematic deviations of approximately 9% under high-temperature conditions. The study provides a physically grounded interpretation of acoustic behaviour under coupled-field conditions and offers a basis for improving the reliability of sonar-based detection in salt cavern environments. The proposed framework further contributes to the modelling of thermo-acoustic interactions in complex subsurface energy systems.</p> ]]> Multiphysics Modelling of Thermo-Concentration Coupled Acoustic Propagation in Salt Cavern Gas Storage Systems yang wang yu wang doi: 10.56578/jcmes010103 Journal of Complex and Multiphysics Engineering Systems 03-23-2026 Journal of Complex and Multiphysics Engineering Systems 03-23-2026 2026 1 1 Article 55 10.56578/jcmes010103 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010103 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010102 The human menstrual cycle is a nonlinear endocrine oscillator that can be modeled using classical mathematical methods. Most mathematical models describe menstrual dynamics using integer-order differential equations. However, there are many clinical observations that suggest that the endocrine system has memory properties, and the effects of hormonal contraceptives can last beyond the time frame suggested by the classical models. In this paper, we propose a fractional dynamical model of the human menstrual cycle that takes into account the effects of hormonal contraceptives. The fractional derivative is used to model the memory and delayed response characteristics of the endocrine system. In addition, we propose a new geometric invariant called the Hormonal Cycle Energy (HCE). The HCE is defined as a phase integral that represents the strength of endocrine oscillations. The stability and bifurcation analysis indicate that increasing the exogenous hormone dosage leads to deformation and eventual collapse of the limit cycle via a Hopf-type bifurcation. The fractional order analysis indicates that the fractional memory affects the level of suppression, the time to recover from the suppression after the withdrawal of exogenous hormones, and the hysteresis in the recovery of the hormonal cycle. The persistent homology analysis indicates that the physiological cycles exhibit nontrivial topological features, while the suppressed cycles have trivial topology and zero HCE. The proposed model combines fractional calculus, dynamical systems theory, persistent homology, and topological data analysis to investigate endocrine suppression. The results also suggest that the HCE can serve as a biomarker of endocrine vitality and recovery. 03-22-2026 <![CDATA[ The human menstrual cycle is a nonlinear endocrine oscillator that can be modeled using classical mathematical methods. Most mathematical models describe menstrual dynamics using integer-order differential equations. However, there are many clinical observations that suggest that the endocrine system has memory properties, and the effects of hormonal contraceptives can last beyond the time frame suggested by the classical models. In this paper, we propose a fractional dynamical model of the human menstrual cycle that takes into account the effects of hormonal contraceptives. The fractional derivative is used to model the memory and delayed response characteristics of the endocrine system. In addition, we propose a new geometric invariant called the Hormonal Cycle Energy (HCE). The HCE is defined as a phase integral that represents the strength of endocrine oscillations. The stability and bifurcation analysis indicate that increasing the exogenous hormone dosage leads to deformation and eventual collapse of the limit cycle via a Hopf-type bifurcation. The fractional order analysis indicates that the fractional memory affects the level of suppression, the time to recover from the suppression after the withdrawal of exogenous hormones, and the hysteresis in the recovery of the hormonal cycle. The persistent homology analysis indicates that the physiological cycles exhibit nontrivial topological features, while the suppressed cycles have trivial topology and zero HCE. The proposed model combines fractional calculus, dynamical systems theory, persistent homology, and topological data analysis to investigate endocrine suppression. The results also suggest that the HCE can serve as a biomarker of endocrine vitality and recovery. ]]> Nonlinear Dynamics of the Menstrual Cycle: Fractional Modeling, Cycle Energy, and Contraceptive Suppression a. y. xani n. yildirim doi: 10.56578/jcmes010102 Journal of Complex and Multiphysics Engineering Systems 03-22-2026 Journal of Complex and Multiphysics Engineering Systems 03-22-2026 2026 1 1 Article 38 10.56578/jcmes010102 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010102 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010101 The profound computational expense required to analyze complex wave propagation within advanced architected materials presents a formidable barrier to the rapid design of novel periodic structures. To resolve this critical bottleneck, this research introduces a highly accelerated semi-analytical computational framework. The methodology leverages Bloch mode synthesis (BMS) to execute profound interior domain condensation, drastically reducing system degrees of freedom (DOF) without sacrificing precision. Simultaneously, an algebraic null space matrix projection is deployed to mathematically eliminate constraint dependencies and efficiently impose periodic boundary conditions (PBCs), thereby guaranteeing ultra-fast processing. To rigorously demonstrate the versatility and predictive power of the proposed solver, a fundamentally novel topology, termed the curved re-entrant hybrid metamaterial (CRHM), is introduced as an evaluative test bed. This unique architecture strategically embeds parametric Bezier curves within a foundational lattice, leveraging precise geometric curvature to seamlessly govern local resonance and elastic scattering phenomena. The numerical outputs generated by the solver for this advanced geometry are then systematically compared against standard unit cell analyses utilizing MATLAB and the COMSOL Multiphysics. Before fully evaluating this geometry, the proposed framework is strictly validated against a curved re-entrant honeycomb (RH), an established literature benchmark, to confirm numerical reliability. Following this rigorous verification, comprehensive evaluations of the CRHM uncover deep subwavelength wave isolation directly resulting from its topological arrangement, demonstrating its exceptional versatility for both independent application and integration within broader multi-physics systems. These attenuation characteristics are corroborated through finite array transmission cross verifications utilizing both MATLAB and COMSOL. Exploiting the rapid evaluation cycles afforded by the numerical formulation, comprehensive structural sweeps elucidate a fundamental physical trade-off balancing cumulative attenuation capacity against uninterrupted spectral continuity. This explicit behavioral mechanism provides engineers with a highly predictable tuning strategy to satisfy diverse broadband isolation criteria. Beyond these spectral attenuation capabilities, rigorous iso-frequency verifications reveal profound spatial anisotropy inherent to the unit cell design. Supported by explicit directivity analyses for verifying group velocities, the calculated divergence between phase and group velocity vectors facilitates high directivity, permitting the targeted routing of wave energy along strictly defined spatial trajectories. Ultimately, integrating this highly efficient framework with the customizable CRHM topology establishes a scalable paradigm for engineering advanced wave mechanics, demonstrating utility in both isolated operations and coupled multi-physics architectures. 03-20-2026 <![CDATA[ <p>The profound computational expense required to analyze complex wave propagation within advanced architected materials presents a formidable barrier to the rapid design of novel periodic structures. To resolve this critical bottleneck, this research introduces a highly accelerated semi-analytical computational framework. The methodology leverages Bloch mode synthesis (BMS) to execute profound interior domain condensation, drastically reducing system degrees of freedom (DOF) without sacrificing precision. Simultaneously, an algebraic null space matrix projection is deployed to mathematically eliminate constraint dependencies and efficiently impose periodic boundary conditions (PBCs), thereby guaranteeing ultra-fast processing. To rigorously demonstrate the versatility and predictive power of the proposed solver, a fundamentally novel topology, termed the curved re-entrant hybrid metamaterial (CRHM), is introduced as an evaluative test bed. This unique architecture strategically embeds parametric Bezier curves within a foundational lattice, leveraging precise geometric curvature to seamlessly govern local resonance and elastic scattering phenomena. The numerical outputs generated by the solver for this advanced geometry are then systematically compared against standard unit cell analyses utilizing MATLAB and the COMSOL Multiphysics. Before fully evaluating this geometry, the proposed framework is strictly validated against a curved re-entrant honeycomb (RH), an established literature benchmark, to confirm numerical reliability. Following this rigorous verification, comprehensive evaluations of the CRHM uncover deep subwavelength wave isolation directly resulting from its topological arrangement, demonstrating its exceptional versatility for both independent application and integration within broader multi-physics systems. These attenuation characteristics are corroborated through finite array transmission cross verifications utilizing both MATLAB and COMSOL. Exploiting the rapid evaluation cycles afforded by the numerical formulation, comprehensive structural sweeps elucidate a fundamental physical trade-off balancing cumulative attenuation capacity against uninterrupted spectral continuity. This explicit behavioral mechanism provides engineers with a highly predictable tuning strategy to satisfy diverse broadband isolation criteria. Beyond these spectral attenuation capabilities, rigorous iso-frequency verifications reveal profound spatial anisotropy inherent to the unit cell design. Supported by explicit directivity analyses for verifying group velocities, the calculated divergence between phase and group velocity vectors facilitates high directivity, permitting the targeted routing of wave energy along strictly defined spatial trajectories. Ultimately, integrating this highly efficient framework with the customizable CRHM topology establishes a scalable paradigm for engineering advanced wave mechanics, demonstrating utility in both isolated operations and coupled multi-physics architectures.</p> ]]> Elastic Wave Isolation and Highly Directive Wave Propagation in Architected Two-Dimensional Metamaterials: An Accelerated Algebraic Approach amir mohammad balizadeh amin yaghootian hamid m. sedighi doi: 10.56578/jcmes010101 Journal of Complex and Multiphysics Engineering Systems 03-20-2026 Journal of Complex and Multiphysics Engineering Systems 03-20-2026 2026 1 1 Article 1 10.56578/jcmes010101 https://www.acadlore.com/article/JCMES/2026_1_1/jcmes010101