Search Results (1,575)

Developing Cu-based composites with excellent electrical and mechanical properties under multiphysics-coupled service conditions remains challenging. Novel Cu-Nb-Gr composites were fabricated by high-energy ball milling and High-pressure Multi-field Assisted Rapid Sintering. Experiments combined with computational fluid dynamics (CFD) and finite element method (FEM) simulations were used to investigate how Gr regulates material performance. The incorporation of 3 vol.% Gr promoted the formation of a semi-continuous Gr-rich structure coupled with an Nb-rich load-bearing structure. Under arc erosion, the semi-continuous Gr-rich structure provided efficient heat-conduction pathways, reducing the peak temperature and metal-vapor recoil force, while the Nb-rich load-bearing structure suppressed liquid–metal spattering and stabilized the molten pool. Simultaneously, Gr dynamically spread to form a continuous solid-lubricating film during sliding friction, significantly reducing the coefficient of friction and interfacial shear stress. Furthermore, under compressive loading, the semi-continuous Gr-rich structure coupled with the Nb-rich load-bearing structure alleviated interfacial elastic–modulus mismatch and extreme stress concentration, limiting macroscopic plastic deformation of the matrix. Consequently, Cu-Nb-3Gr achieved a favorable balance of arc-erosion resistance, wear resistance, and compressive performance, providing a new strategy for improving conventional Cu-based composites. Full article

Centrifugal atomization is used to generate droplets or particles in processes ranging from crop protection and metallurgical powder production to rotary-bell coating, combustion, and spray-based product processing. However, comparison across studies is hindered by differences in atomizer geometry, characteristic scales, fluid properties, operating windows, diagnostic methods, and performance metrics. This article presents a structured critical review of centrifugal atomization mechanisms, investigation methods, and multidisciplinary applications. The literature is organized according to operational definitions, atomizer configuration, liquid-film evolution, primary and secondary breakup, experimental and numerical approaches, and application-level performance. Rather than assuming universal phase boundaries, the review synthesizes reported transition criteria for direct-drop, ligament, and film breakup and examines their dependence on geometry, liquid throughput, rotational speed, fluid rheology, surface tension, and surrounding-gas conditions. Across applications, the available evidence indicates that rotational speed and liquid throughput strongly affect film thickness and breakup intensity, but their influence on droplet or particle size remains conditional on the prevailing regime and device geometry. The review further compares the strengths, limitations, validation status, and transferability of commonly used experimental and computational methods. Remaining priorities include standardized definitions of characteristic scales, matched-condition comparisons, uncertainty reporting, benchmark datasets for multiphysics models, and testable criteria for scale-up and cross-application transfer. Full article

The large aspect ratio micro end mill is a critical tool for microstructure machining, and its performance directly determines processing quality and efficiency. Diamond coatings are commonly applied to cutting edges to enhance wear resistance and extend tool life. However, existing coating techniques often suffer from poor uniformity and inadequate consistency, limiting batch production and process stability. Aerosol jet printing (AJP) offers a cost-effective and highly controllable alternative for the efficient, large-scale deposition of diamond coatings on micro end mills, where precise control of line spacing is essential to achieving coating uniformity. In this study, a transient numerical model of droplet deposition in AJP is developed using computational fluid dynamics (CFD). The volume of fluid (VOF) method and the discrete phase model (DPM) are coupled to track liquid–gas interface deformation and diamond particle motion, enabling the dynamic evolution of droplet deposition to be captured. The effects of inter-droplet distance on deposition, spreading, coalescence, and line uniformity are systematically investigated. Droplet deposition mechanisms are analyzed under low-speed jetting conditions, while high-speed jetting simulations are conducted to reflect industrial processing scenarios. The results show that under low-speed jetting, droplets undergo spreading, contraction, and rebound, eventually forming a uniform cap-like structure. Under high-speed jetting, droplets exhibit a dispersed ring-shaped spreading pattern; although uniformity is slightly reduced, the spreading area and deposition efficiency are significantly increased. These findings provide a theoretical basis for optimizing AJP process parameters to achieve high-quality diamond coatings on micro end mills. Full article

Inadequate cleaning of flexible endoscope channels remains a major cause of healthcare-associated infections despite established reprocessing protocols. We developed biomimetic carbon balls inspired by mustard seed surface features as a brush-free adjunct for endoscope channel cleaning, combining mild mechanical action with adsorption-based removal of organic debris. Activated carbon (AC) balls and carbon fiber (CF) balls with diameters of 1.8–3.0 mm were fabricated to fit 2.5–3.5 mm working channels and characterized by TGA, BET, SEM, and EDS. Cleaning performance was evaluated using tomato powder residue and microbiological validation, and computational fluid dynamics was used to assess flow behavior in a 2.7 mm channel containing a 2.6 mm ball under suction. CF balls showed more uniform thermal degradation (8.9% residual mass at 1000 °C) and a ribbed fibrous morphology. In contrast, AC balls exhibited porous, irregular structures with strong adsorption capacity, characterized by high thermal stability (86.4–89.3% residual mass) and pore volumes of 0.087–0.108 cm³/g and BET surface areas of 63.00 m²/g and 21.65 m²/g. After residue exposure, AC surfaces retained more particulate matter, while CF surfaces remained cleaner and promoted more pronounced wall interaction. Microbiological testing showed effective decontamination, with bacterial counts reduced below the detection limit. CFD analysis demonstrated pressure-driven gap flow, elevated local velocity, and vortex-induced wall shear stress sufficient to enhance debris removal without apparent channel damage. These results suggest that mustard seed-inspired carbon balls provide a promising brush-free strategy for endoscope reprocessing by integrating adsorption, hydrodynamic agitation, and gentle scouring to improve cleaning safety and efficacy. Full article

The lack of freshwater in the world requires a paradigm shift from linear water consumption to resilient and low-energy desalination technologies. Although reverse osmosis (RO) is the standard in the industry, its usefulness is essentially constrained by concentration polarization (CP) and non-useful hydraulic pressure losses. This paper applies a high-fidelity computational model in ANSYS Fluent 2022 R1 to conduct a comparative parametric evaluation of hexagonal and sinusoidal feed-spacer geometries relative to a baseline grid configuration. The solute concentration gradients at the fluid–membrane interface were solved using a 3D species transport model, which was optimized using one-micron near-wall inflation layers. The hexagonal configuration produced the lowest maximum membrane-surface salt mass fraction, decreasing it from 0.1127 kg/kg for the baseline grid to 0.0429 kg/kg, corresponding to a 61.9% reduction. Although the hexagonal design required an inlet pressure of 205.7 Pa, it produced a more favorable normalized mass-transfer–friction trade-off than the sinusoidal configuration (447.8 Pa), with a System Performance Index (η) of 2.53. These results demonstrate comparative micro-scale improvements in concentration polarization control and hydraulic performance under the simulated conditions. Experimental testing and system-level modeling are required before conclusions can be drawn regarding full-module energy consumption, photovoltaic integration, long-term fouling behavior, or economic feasibility. This study is consistent with the emerging Concepts and design for sustainability, whereby a circular and energy-efficient water economy is facilitated through an innovative mechanical design. Full article

Based on the decoupled n-dodecane skeletal mechanism and the computational fluid dynamics (CFD) numerical framework, a multilayer feedforward neural network surrogate model was developed to predict ignition delay in a constant-volume combustion vessel. The Levenberg–Marquardt optimizer with adaptive damping coefficients was used for model training, with mean squared error as the loss function and an inherent early stopping mechanism to prevent overfitting without additional weight decay regularization. To eliminate random interference from initial parameter settings, the surrogate model underwent 1000 repeated training trials, each with random weight re-initialization. The effects of hidden neurons, data partition strategy, normalization scheme, and sample size on predictive performance were systematically examined. The optimal configuration—three hidden neurons, a 70:15:15 data split, and a 105-sample training set—showed low sensitivity to data normalization. The resulting surrogate model is concise and sample-efficient, maintaining satisfactory prediction accuracy at 800 K and 1100 K while substantially reducing computational overhead. It provides a practical and reliable tool for subsequent combustion prediction and uncertainty quantification of hydrocarbon fuels. The feedforward neural network surrogate model substantially cuts the computational overhead for fuel combustion prediction to merely 15–20 min for every batch of 60 samples. Full article

This study presents a comprehensive experimental and numerical investigation of a rotating propeller using three-dimensional Digital Image Correlation (3D DIC), Computational Fluid Dynamics (CFD), and Finite Element Method (FEM) analysis. The main objective was to assess the applicability and accuracy of 3D DIC for full-field displacement and strain measurements under centrifugal loading conditions. The propeller geometry was reconstructed using 3D scanning and implemented in a numerical model with material parameters identified through mechanical testing. Experimental measurements were carried out on a dedicated test stand, enabling controlled rotational speed and synchronized image acquisition. Particular attention was devoted to measurement uncertainty, including calibration errors, motion effects, and coordinate system alignment. The obtained displacement and strain fields were compared with FEM predictions after proper spatial transformation for rotational speeds of 4110, 6045, and 6940 rpm. The results demonstrate good agreement between numerical and experimental data in selected regions, confirming the potential of 3D DIC for validation of rotating structures, while also highlighting limitations related to dynamic effects and optical constraints. Full article

The microstructure of ternary precursors significantly influences the electrochemical performance of ternary cathode materials and, consequently, the overall performance of lithium-ion batteries. In industrial production utilizing traditional co-precipitation methods, Scanning Electron Microscopy (SEM) is typically employed for particle detection. However, this approach is limited by offline sampling lag, poor representativeness, cumbersome sample preparation, and low efficiency, failing to achieve real-time quality feedback on production lines. To enable high-throughput particle detection, this study proposes a multi-layer PDMS chip designed for three-dimensional (3D) hydrodynamic focusing. The sheath fluid compressed the sample flow in horizontal and vertical directions, respectively, to form a flat ribbon flow passing through the detection area. High-fidelity raw images are captured for automated particle microstructure analysis. Firstly, a chemical pretreatment protocol was optimized to ensure stable precursor solution transport. Secondly, a three-layer composite microchannel featuring a sequential horizontal and vertical sheath-flow compression mechanism was designed, with its geometry optimized via Computational Fluid Dynamics (CFD) simulations. Subsequently, experimental optimizations of flow rate ratios were performed using sodium fluorescein, followed by validation with ternary precursor solutions. The results indicate that the microchannel achieves flattened monolayer focusing of randomly distributed precursor particles, compressing the sample stream height to approximately 15.44 μm, thereby maintaining the particle stream within the microscope’s depth of field and analyzing particle microstructure efficiently based on a microscopic image. Moreover, it is confirmed that the focused stream dimensions are primarily governed by the flow rate ratio, allowing for a flexible increase in detection throughput by adjusting the total flow rate. Different from static offline particle analyzers, this platform captures dynamic particle morphology under continuous flow, providing real-time data to guide co-precipitation reaction adjustment. Full article

Slag splashing protection is the dominant technology for extending refractory lining service life and enhancing production efficiency in basic oxygen furnace (BOF) steelmaking. However, the intrinsic mechanism of gas-slag-steel multiphase coupled splashing remains poorly understood, and existing numerical methods suffer from prohibitive computational costs and inaccurate characterization of interfacial momentum transfer and multiphase interactions. This study establishes a fully coupled three-dimensional numerical model integrating Volume of Fluid (VOF)–Discrete Particle Method (DPM) bidirectional phase transition, adaptive mesh refinement (AMR), and Eulerian Wall Film Model (EWFM), and the multiphase flow simulation in this study adopts constant thermophysical parameters of molten steel and slag at the industrial splashing temperature of 1650 °C. Taking the Blowing Number (N_B) as the core similarity criterion, a 1:10 scaled geometric model of a 50-ton industrial BOF is employed to systematically investigate the regulatory effects of top-blowing flow rate, lance height, and N_B on droplet splashing behavior and wall liquid film evolution. The model is validated against mercury-glycerol cold model experimental data, with a relative error of less than 3% in total splashing mass prediction. Results demonstrate that increasing N_B significantly enhances splashing intensity. Under optimal conditions (200 mm lance height, 11.76 Nm³/h flow rate, N_B = 9.30), the wall liquid film fully covers the middle-upper furnace wall with a uniform thickness of 0.8–1.2 mm. N_B dominates jet momentum distribution: high N_B forms a deep-penetrating four-lobed impact cavity, remarkably improving droplet axial momentum and residence time. Molten steel droplets concentrate at 3–4 mm, while slag droplets shift to 2–4 mm at high flow rates of 11.76 Nm³/h, with maximum slag droplet production at N_B = 6.99. This work provides reliable theoretical support for industrial BOF slag-splashing process optimization. Full article

Solar-Driven Photothermal Membrane Distillation (SPMD) integrates solar energy using photothermal coatings on the hydrophobic membranes, such as carbon black nanoparticles coated on PVDF membranes, to achieve localized heating at the liquid–vapor interface. This approach enhances energy efficiency by mitigating temperature polarization and reducing thermal energy demands compared to conventional membrane distillation (MD). However, the challenges of fouling and scaling, which can significantly impair membrane performance, continue to be a serious concern, similar to other MD configurations. This comprehensive review establishes a unified framework connecting core transmembrane mass and heat transfer mechanisms with the thermodynamic pathways of surface fouling and scaling. We critically evaluate various strategies for mitigating scaling and fouling, including the development of omniphobic membranes, the introduction of nano/micro bubbles, the addition of anti-scalants and surfactants, and the implementation of chemical and mechanical pretreatments. Subsequently, the impact of photothermal coatings, applied to the feed–membrane interface in SPMD to absorb solar radiation, on scaling and fouling resistance is also discussed. Finally, we provide a comprehensive review of advanced computational paradigms, for both coupled radiative-thermal and dynamic fouling models—contrasting deterministic, physics-based multi-phase Computational Fluid Dynamics (CFD) with empirical Response Surface Methodology (RSM) and predictive Artificial Intelligence (AI) data-driven models. Beyond this survey, we identify and directly address a critical, previously unquantified gap in the field of SPMD: the absence of an explicit thermodynamic link between transmembrane heat/mass transfer and the nucleation and adhesion processes that govern scaling and fouling, and we further highlight the practical barriers—photothermal coating durability, economic feasibility, and technology readiness—that currently separate laboratory-scale SPMD from field deployment. This holistic synthesis charts future engineering strategies for scalable, fouling-resistant, and optimized solar-driven desalination infrastructure. Full article

Polyurethane adhesives often suffer from high viscosity, poor flowability, and limited mass transfer efficiency, making it challenging for conventional single-shaft or twin-shaft mixing systems to achieve uniform mixing in large-capacity equipment. This study investigates the differential speed coupling mechanism of a 600 L eccentric four-shaft mixer for high-viscosity polyurethane adhesive systems using computational fluid dynamics (CFD). The effects of different differential speed ratios on flow field evolution and mixing performance were systematically analyzed through multiple indicators, including power consumption per unit volume, velocity variation coefficient, effective mixing region ratio, vortex core coverage, and maximum Lyapunov exponent (LLE). Among the investigated conditions, the 50:100 differential speed ratio exhibited a more favorable circulation pattern, forming a closed-loop circulating flow field in the entire reactor, with an effective mixing region accounting for 60%, a velocity variation coefficient of only 0.38, and a power consumption per unit volume as low as 21.2 W/m³. A constant speed of 100:100 easily generates dead zones in the interaxial flow field, while a high differential speed of 100:50 leads to excessive disturbances and energy waste. Moderate differential speed can generate large-scale coupled vortices, thereby enhancing mixing through coupled axial transport, radial dispersion, and tangential shear. An eccentric four-shaft mixer combined with reasonable differential speed control can effectively improve flow field uniformity and reduce potential mixing limitations in large-scale polyurethane adhesive systems. Among the three investigated differential speed ratios, the 50:100 condition exhibited the most favorable overall mixing performance. These findings provide numerical insights into the selection of differential speed operating conditions for high-viscosity polyurethane adhesive mixing systems. Full article

Background/Objectives: Clear cell renal cell carcinoma (ccRCC) is frequently vascular and immune-infiltrated, yet durable responses to immune checkpoint blockade remain limited. This suggests that immune resistance may reflect tumor microenvironmental organization and mechanotransduction state rather than immune infiltration alone. We aimed to determine whether matrix reorganization and branch-specific integrin mechanosensing define immune-regulatory states in ccRCC, with particular attention to adenosine-associated immune resistance. Methods: We performed an integrative computational analysis of TCGA-KIRC bulk RNA-sequencing, clinical, survival, immune feature, and reverse-phase protein array data. Matrix- and mechanobiology-related programs were quantified using ssGSEA, compact z-score-based signatures, and principal component-based sensitivity analyses. Immune-regulatory programs, CAF and ECM scores, FAK/SRC activation features, and MINER-inferred transcriptional regulons were integrated using stage association, correlation, partial correlation, variance partitioning, survival, and transcriptional state analyses. Results: Matrix-centered transcriptional programs were the dominant stage-associated mechanobiology signal in ccRCC, including ECM deposition, collagen organization, matrix remodeling, fluid shear stress, and YAP/TAZ activity. A compact ECM-associated core (ECM_Stiffness_Core; a ten-gene signature whose highest-loading members include FN1, COL1A1, COL6A1, and LOX) captured a matrix reorganization program, indicating remodeling of ECM composition and architecture rather than uniform increases in tumor stiffness, pressure, or bulk mechanical load. Matrix remodeling was associated with CAF abundance, TGFβ signaling, CD276/B7-H3, CSF1-related myeloid biology, ENTPD1/CD39, and PRDM1, whereas associations with cytotoxic immune cells were weaker. Integrin mechanosensing separated into opposing branches: ITGA5/ILK/SRC-associated features aligned with higher-risk biology and adenosine-linked immune regulation, whereas PTK2/FAK–RHOA–ROCK components showed lower-risk directions. RPPA analyses supported SRC–FAK imbalance as an adverse signaling pattern. MINER analyses further separated matrix-associated immune-suppressive regulons from canonical integrin/focal adhesion states. Conclusions: Matrix reorganization and integrin branch imbalance appear to shift ccRCC toward distinct immune-regulatory states. We propose a conceptual model that matrix architecture may act as a directional suppressive amplifier, whereas the relative balance between ITGA5/ILK/SRC-associated signaling and canonical PTK2/FAK–RHOA–ROCK mechanosensing functions as an integrin branch rheostat. This framework identifies matrix remodeling, CD276/B7-H3, CSF1-related myeloid biology, adenosine signaling, and SRC–FAK imbalance as candidate biological axes for future investigation, including their potential relevance to combination strategies beyond PD-1/PD-L1 blockade. Future experimental, spatial, and treatment response studies may further clarify the mechanistic basis of these associations and evaluate their potential therapeutic relevance. Full article

Objectives: To compare the geometric design, metallurgical properties, mechanical performance, and irrigation dynamics of Reciproc Minima (M20 and M25) and Reciproc Blue R25 instruments. Methods: One hundred and eighty instruments (n = 60/group) were evaluated. Geometry was analyzed using stereomicroscopy, scanning electron microscopy, and 3D surface scanning. Metallurgical characteristics were assessed by energy-dispersive X-ray spectroscopy and differential scanning calorimetry. Mechanical performance tests (n = 10/group) included cyclic fatigue, torsional resistance, bending resistance, buckling resistance, and cutting efficiency. Irrigation dynamics were examined through computational fluid dynamics simulations based on a micro-CT-derived mandibular molar model prepared according to each system and combined with open-ended, side-vented, or double side-vented needles. Data were analyzed using one-way ANOVA or Kruskal–Wallis tests (α = 0.05). Results: The results showed that blade dimensions increased progressively from Minima M20 to Reciproc Blue R25. All instruments had S-shaped cross-sections and non-active tips. Energy-dispersive spectroscopy confirmed near-equiatomic NiTi composition, and similar phase transformation temperatures were observed across groups. Minima M20 showed the highest cyclic fatigue resistance (p < 0.0001), whereas Minima R25 exhibited greater angular deflection (p < 0.0001). Reciproc Blue R25 had the highest buckling resistance and lowest flexibility (p < 0.0001). M25 showed the lowest axial force, indicating the numerically highest cutting efficiency, but it did not differ significantly from Reciproc Blue R25 (p > 0.05). No needle delivered irrigant to working length. The open-ended needle achieved greater apical penetration, particularly with Reciproc Blue R25. Minima M20 generated the highest wall shear stress, and Reciproc Blue R25 the lowest apical pressure. Conclusions: Reciproc Minima and Reciproc Blue R25 showed similar metallurgical characteristics; however, differences in geometric design resulted in distinct mechanical behaviors and irrigation fluid dynamics. These findings suggest that low-taper reciprocating instruments may represent a conservative alternative in anatomically challenging canals, while clinicians should consider the associated differences in mechanical behavior and irrigation dynamics when selecting the most appropriate instrument. Full article

Autonomous underwater vehicles (AUVs) are increasingly used in seabed inspection, underwater search, ocean observation, and infrastructure maintenance. However, feasible and safe trajectory planning in dense three-dimensional underwater environments remains challenging because AUVs must avoid multiple irregular static obstacles, react to moving obstacles, and maintain robust navigation performance under ocean-current disturbances. Traditional path planning methods can suffer from high computational cost or poor trajectory smoothness in dense 3-D environments. The interfered fluid dynamical system (IFDS) provides a promising flow-field-based planning mechanism by treating obstacles as disturbance sources in a virtual fluid field. Nevertheless, the performance of IFDS strongly depends on the repulsive and tangential parameters, which are usually selected empirically and may not provide an optimal trade-off among path length, smoothness, safety margin, and energy consumption. To address these issues, this paper proposes a grey wolf optimization-enhanced IFDS method, termed GWO-IFDS. First, static and dynamic underwater obstacles are modeled using unified super ellipsoid implicit functions, allowing spheres, cylinders, ellipsoids, reefs, and seabed mounds to be described in a common mathematical form. Second, a 3-D IFDS planner is developed to generate collision-free streamlines by combining the attractive flow toward the target and obstacle-induced modulation matrices. Third, a grey wolf optimization algorithm is introduced to optimize the IFDS repulsive and tangential parameters by minimizing a scalarized multi-criteria fitness function that considers path length, terminal error, trajectory smoothness, energy proxy, and minimum obstacle clearance. Finally, simulation studies are conducted under four representative scenarios: multiple static obstacles, mixed static and dynamic obstacles, mixed obstacles with ocean-current disturbances, and parameter-optimization comparison among GWO, PSO, DE, BO, GA, and fixed-parameter IFDS. The results demonstrate that the proposed GWO-IFDS method can generate smoother and safer trajectories with lower steering-effort-related cost than fixed-parameter IFDS. Additional tests under sonar-like perception uncertainty, bounded steering constraints, and different weight settings further verify the robustness and feasibility of the proposed framework. Full article

With the development of morphing aircraft, understanding the fluid–structure interaction (FSI) mechanisms of multibody systems composed of rigid and flexible components has become increasingly important. The coupled motion and deformation of such systems in a flow field give rise to complex nonlinear FSI problems. Here, we propose a fluid–multibody–structure interaction framework that couples a finite volume Navier–Stokes solver, a multibody dynamics solver, and radial basis function interpolation for fluid–structure data transfer. The framework is validated using a benchmark case and subsequently applied to simulations of a two-segment flexible beam and a three-dimensional continuously variable-sweep wing. The results show that the presence of joints and structural flexibility substantially affects the FSI response: hinge location markedly alters the FSI characteristics of the multibody flexible-beam system, while increasing the sweep angle during continuous morphing reduces the aerodynamic force coefficients and structural flexibility induces persistent fluctuations in aerodynamic loads. A key contribution of the proposed framework is its ability to capture both active morphing motions and passive aeroelastic deformations simultaneously. Compared with approaches based on inviscid, incompressible aerodynamic models, the present high-fidelity flow solver can better resolve complex flow phenomena during morphing. This framework provides a useful numerical tool for investigating FSI mechanisms in morphing aircraft. Its current limitations include the computational cost of global radial basis function interpolation for large multibody systems and its applicability being restricted to low-Mach-number flows. Full article