Optimal Transfer Research Articles

Embryo Cryopreservation Strategy May Improve Live Birth for Women Underwent In Vitro Maturation After Early Oocyte Retrieval: A Retrospective Cohort Study.

There is limited clinical research investigating the optimal transplantation strategy in early oocyte retrieval cycles. We aimed to assess whether the maturation of oocytes from early oocyte retrieval influenced pregnancy outcomes, and to find the optimal embryo transfer strategy (fresh or frozen-thawed embryo transfers) for patients who had early oocyte retrieval and underwent in vitro maturation (IVM). A retrospective cohort study was conducted in a university-based reproductive medical center. A total of 234 women who underwent single embryo transfer after early oocyte retrieval were included. The primary outcome was live birth rate. The live birth rate (12.5% vs. 27.5%, p = 0.005, adjusted p = 0.010) was significantly lower in IVM cycles compared with no IVM cycles. There was a significant decrease in live birth (3.6% vs. 19.0%, p = 0.008, adjusted p = 0.011) and a markedly elevated early pregnancy loss rate (62.5% vs. 11.1%, p = 0.014, adjusted p = 0.012) for IVM fresh cycles compared with no IVM fresh cycles. However, these findings were not repeated in subgroup analysis when frozen-thaw embryos were transferred. These results indicate that patients who underwent early oocyte retrieval and then IVM-intracytoplasmic sperm injection should be recommended the embryo cryopreservation strategy. Resynchronization of the embryo and the endometrium in frozen-thaw embryo transfer cycles may optimize live birth and decrease early pregnancy loss in IVM-intracytoplasmic sperm injection cycles after early oocyte retrieval.

Experimental research on heat transfer enhancement by a wall-proximity circular cylinder under an axial magnetic field

This work experimentally investigates the flow and heat transfer of liquid metal around a cylinder in a rectangular channel with a heated bottom wall under an axial magnetic field. Wall electrical potential probes measure the streamwise and vertical velocity components, while an immersed array probe measures the temperature distribution in the vertical profile. The coupling effects of the gap ratio (ratio of the distance between the center of the cylinder and the wall to the diameter of the cylinder) and the magnetic field on heat transfer enhancement are studied. The experimental results suggest that the Lorentz force suppresses the wall recirculation zone from shedding secondary vortices and alters the trajectory of the vortex street, affecting the thermal boundary layer. The probability density function of temperature indicates that the magnetohydrodynamics effect causes a bimodal distribution due to a quasi-two-dimensional vortex street and a trimodal distribution due to additional secondary vortices. The vortex street notably reduces the thermal boundary layer thickness and the local temperature of the heated wall. The analysis of the correlation coefficients between velocity and temperature fluctuations and the frequency spectrum reveals the physical mechanism enhancing heat transfer. The wall-proximity effect and buoyancy strengthen flow fluctuations and enhance heat transfer. For Ha (Hartmann number) ranging from 161.6 to 646.4, optimal heat transfer occurs at G/d = 1.0, whereas for 808 ≤ Ha ≤ 1131.2, optimal heat transfer is achieved at G/d = 0.5, which is attributed to the coupling effect of the magnetic field and gap flow on vortex dynamics.

Interface Engineering of RuO2/Ni-Co3O4 Heterostructures for enhanced acidic oxygen evolution reaction

RuO2 has been recognized as a standard electrocatalyst for acidic oxygen evolution reaction (OER). Nonetheless, its high cost and limited durability are still ongoing challenges. Herein, a RuO2/Ni-Co3O4 heterostructure confining a heterointerface (between RuO2 and Ni-doped Co3O4) is constructed to realize enhanced OER performance. Specifically, RuO2/Ni-Co3O4 containing a low Ru content (2.7 ± 0.3 wt%) achieves an overpotential of 186 mV at a current density of 10 mA cm−2 with a long-run stability (≥1300 h). Also, it exhibits a mass activity of 1202.29 mA mgRu-1 at an overpotential of 250 mV, exceeding commercial RuO2. The results disclose an optimum electron transfer at the heterointerface, wherein Ni doping improves the adsorption energy of oxygen-containing intermediates, thereby facilitating OER. This study presents an effective approach for designing highly active and stable OER electrocatalysts.

A recommendation model for optimizing transfer learning hyper-parameter settings in building heat load prediction with limited data samples

The transfer learning method has gained increasing attention in the domain of building load prediction, particularly in scenarios with limited data samples. Its core principle involves leveraging knowledge obtained from abundant data in source buildings to aid the learning process of models for the target buildings. Existing research has predominantly concentrated on optimizing the selection of source building data to improve transfer learning effectiveness, while the optimization of transfer learning hyper-parameter settings is often neglected. This study proposes a recommendation model tailored for transfer learning hyper-parameter settings in the context of small sample prediction for building heat loads. The objective is to automatically suggest suitable transfer learning hyper-parameter combination based on the specific features of the building heat load data samples. In this study, 200 real building profiles were utilized to generate the input–output dataset required for the recommendation model. By employing data mining techniques such as clustering and classification, the correlation between the features of source building data and the most effective transfer learning hyper-parameter combination is investigated. The developed recommendation model for optimal transfer learning hyper-parameter settings achieves a classification accuracy of 90.5%，and the performance evaluation was conducted using an additional dataset of 30 source buildings. The results show that by employing this recommendation model, the prediction error of the target buildings can be reduced by 0.12% to 6.64% compared to the conventional method of empirically determining transfer learning hyper-parameter settings.

Numerical study on gas-liquid transport uniformity in full-scale flow field of proton exchange membrane fuel cells

Distribution zone governs airflow transmission and distribution within large-scale flow field, which further affects the discharge of liquid water produced. This paper combines experimental validation and computational fluid dynamics (CFD) methods to elevate mass transfer coherence in full-scale flow field (375 cm2). For the first time, circulation number λ and drainage maldistribution (DM) are introduced to quantify variations in water and gas transport homogeneity attributable to the distribution zone. Effect on orientation and spacing of dot matrix, as well as main field structure are investigated. The results reveal that full-scale flow field inlet and outlet distribution zones manage the behavior of gas and liquid transport. Specifically, dot matrix flow field with an inclination angle α = 90° demonstrates superior flow uniformity, while α = 45° exhibits the fastest initial drainage rate. Optimal comprehensive mass transfer and drainage consistency are achieved with a vertical dot matrix spacing of S = 1.2 mm ∼ 1.5 mm, yielding the lowest maldistribution factor (MF) and DM number of 0.15 and 0.04 respectively. This configuration results in a maximum improvement of 58.4 % and 43.1 %. Notably, a novel aspect is that the drainage rate in full-scale flow field follows an exponential distribution, with peak efficiency factor R = 0.29 observed at α = 90°and S = 1.5 mm.

Numerical simulation on flow boiling heat transfer characteristics of R513A in the horizontal microfin tubes

To address the growing demand for high-efficiency heat exchangers in refrigeration, air conditioning, and heat pump systems, this study investigates the boiling heat transfer performance of R513A (an environmentally friendly azeotropic refrigerant) in horizontal microfin and smooth tubes with a 5.89 mm ID. Using 3D transient simulations, the tubes were analyzed under operating conditions of a mass flux of 50 kg/(m2·s) and a saturation temperature of 5 °C. The simulation results were validated against experimental data within a ±10 % error margin, confirming the reliability of model. At the constant mass flux, both the microfin and smooth tubes exhibited predominantly wavy-stratified flow, where surface tension dominated bubble flow. Gravity effects became more pronounced in slug, plug, and wavy-stratified flows. Structural parameters of microfin tubes, such as helical angle, fin height and number of fins, significantly affected flow boiling heat transfer. Increasing the helical angle had limited effect on enhancing boiling heat transfer performance. Microfin tube 4# (helical angle of 28°) exhibited an 11.27 % reduction in the boiling heat transfer coefficient compared to microfin tube 2#, due to the uneven distribution of liquid droplets in the vapor phase further reduced liquid film continuity and thickness. Microfin tube 5# (fin height of 0.30 mm) achieved an average mainstream velocity 1.36 times that of tube 2# (fin height of 0.17 mm), enhancing heat transfer. Conversely, microfin tube 6# with 54 fins showed local drying, negatively impacting its heat transfer efficiency.In summary, microfin tube 5# exhibited the optimal heat transfer characteristics.

A high-performance flexible biopolymer-based Ce oxide composite electrolyte for lithium-ion battery dendrite reduction

We propose a novel solid-state composite polymer electrolyte (CPE) that includes Li7La2.5Ce0.5Zr2O12 (Ce-LLZO), chitosan (CS)/agar-agar (AA) polymer, polyethylene glycol (PEG) plasticizer, and LiClO4 salt. At 25 °C, the CPE3 formulation, consisting of 15 wt% Ce-LLZO, 60 wt% CS-AA, 15 wt% PEG, and 10 wt% LiClO4, demonstrated exceptional lithium (Li)-ion conductivity of 5.18 × 10-3 S cm−1 and an optimal transference number (TLi+) of 0.937. We assessed the electrochemical stability of CPE3 using linear sweep voltammetry, which revealed a maximum stability limit of 4.1 V (versus Li/Li+). In addition, the coin cell made with the Li||CPE3||NMC configuration had an amazing discharge capacity of 163 mAhg-1 and stayed stable for up to 100 cycles at 0.1 °C in room temperature. Conversely, when subjected to Li-plating/stripping cycles, the symmetric Li||CPE3||Li cell exhibited stability for 550 h and maintained a current density of 2.0 mA cm−2. Compared to Li-metal, the proposed material exhibited reduced overpotential while simultaneously enhancing electrochemical stability.

Deterministic Trajectory Design and Attitude Maneuvers of Gradient-Index Solar Sail in Interplanetary Transfers

A refractive sail is a special type of solar sail concept, whose membrane exposed to the Sun’s rays is covered with an advanced engineered film made of micro-prisms. Unlike the well-known reflective solar sail, an ideally flat refractive sail is able to generate a nonzero thrust component along the sail’s nominal plane even when the Sun’s rays strike that plane perpendicularly, that is, when the solar sail attitude is Sun-facing. This particular property of the refractive sail allows heliocentric orbital transfers between orbits with different values of the semilatus rectum while maintaining a Sun-facing attitude throughout the duration of the flight. In this case, the sail control is achieved by rotating the structure around the Sun–spacecraft line, thus reducing the size of the control vector to a single (scalar) parameter. A gradient-index solar sail (GIS) is a special type of refractive sail, in which the membrane film design is optimized though a transformation optics-based method. In this case, the membrane film is designed to achieve a desired refractive index distribution with the aid of a waveguide array to increase the sail efficiency. This paper analyzes the optimal transfer performance of a GIS with a Sun-facing attitude (SFGIS) in a series of typical heliocentric mission scenarios. In addition, this paper studies the attitude control of the Sun-facing GIS using a simplified mathematical model, in order to investigate the effective ability of the solar sail to follow the (optimal) variation law of the rotation angle around the radial direction.

Optimization Investigation of Bionic Fin Structure by Experimental and Numerical Modelling

Drawing inspiration from the fast-swimming shark’s structure and skin, we developed the bionic shark fin, featuring two distinct types: bionic curved fins and bionic curved slotted fins. The present study assessed the impact of mainstream Reynolds number, fin curvature, and fin slot thickness on thermal fluid performance. The findings demonstrated that the curved fin structure can enhance the fluid mixing, benefiting local thermal-hydraulic performance. Simultaneously, the slotted curved fins expanded the heat transfer surface area, and the local injection in slots significantly reduced hydraulic resistance, offering a novel solution for heat sink optimization. Optimal flow and heat transfer performance for bionic curved fins were achieved with the fin thickness of 2.4 mm, while for bionic curved slotted fins, the overall optimal thermal performance was attained with a fin thickness of 2.6 mm with the slot thickness of 1 mm. Overall, the bionic fins exhibited thermal performance improvements of 8.7% and 29% over straight fins, respectively. More importantly, the heat transfer and flow friction correlations with criterion of fin parameters were developed, and the robust predictive accuracy was verified.

Transition from pediatric to adult care system in patients with complex epilepsies: Necker model for transition evaluated on 70 consecutive patients.

Complex epilepsies such as epileptic and developmental encephalopathies require multidisciplinary care throughout life. A coordinated transition program is therefore essential to provide optimal support for patients leaving pediatric for adult care. The aim of this study is to describe and evaluate our transition program for complex epilepsies, focusing on the last step in this program, that is, the multidisciplinary transition day hospital (MTDH). We performed a retrospective observational study including patients with complex epilepsies who underwent the full steps of the transition program at Necker-Enfants Malades Hospital between May 2021 and June 2023, with a follow-up until February 2024. We described the cohort and detailed the interventions performed during the MTDH including medical, medicosocial, educational, daily life abilities, and laboratory and imaging assessments with the participation of one member of the adult team. We evaluated two indicators of our program: (1) the "adult first clinic attendance rate," defined by the percentage of patients attending their first adult clinic; and (2) the "return rate," defined by the percentage of patients who requested a pediatric encounter after their transfer. Our cohort included 70 patients with a mean age of 19.1 years (interquartile range = 16.3-19.5). Eighty percent had an epilepsy syndrome diagnosis; 72.8% were treated with three or more antiseizure medications. All patients had their appointment at the adult clinic within 6 months of the day hospital, and only two families requested a pediatric encounter after the transfer. The transition program is key for an optimal transfer of patients with complex epilepsies to adult care. It requires a comprehensive multidisciplinary approach and provides a complete summary of the medical record. Our program secures a smooth landing in adult care and is a promising model to better manage the challenging transition process, especially in patients with complex epilepsy.

Three-Dimensional Rapid Orbit Transfer of Diffractive Sail with a Littrow Transmission Grating-Propelled Spacecraft

A diffractive solar sail is an elegant concept for a propellantless spacecraft propulsion system that uses a large, thin, lightweight surface covered with a metamaterial film to convert solar radiation pressure into a net propulsive acceleration. The latter can be used to perform a typical orbit transfer both in a heliocentric and in a planetocentric mission scenario. In this sense, the diffractive sail, proposed by Swartzlander a few years ago, can be considered a sort of evolution of the more conventional reflective solar sail, which generally uses a metallized film to reflect the incident photons, studied in the scientific literature starting from the pioneering works of Tsander and Tsiolkovsky in the first decades of the last century. In the context of a diffractive sail, the use of a metamaterial film with a Littrow transmission grating allows for the propulsive acceleration magnitude to be reduced to zero (and then, the spacecraft to be inserted in a coasting arc during the transfer) without resorting to a sail attitude that is almost edgewise to the Sun, as in the case of a classical reflective solar sail. The aim of this work is to study the optimal (i.e., the rapid) transfer performance of a spacecraft propelled by a diffractive sail with a Littrow transmission grating (DSLT) in a three-dimensional heliocentric mission scenario, in which the space vehicle transfers between two assigned Keplerian orbits. Accordingly, this paper extends and generalizes the results recently obtained by the author in the context of a simplified, two-dimensional, heliocentric mission scenario. In particular, this work illustrates an analytical model of the thrust vector that can be used to study the performance of a DSLT-based spacecraft in a three-dimensional optimization context. The simplified thrust model is employed to simulate the rapid transfer in a set of heliocentric mission scenarios as a typical interplanetary transfer toward a terrestrial planet and a rendezvous with a periodic comet.

DL-MD-OKT: deep learning-based prediction model for cross-domain recommendation with multi-auxiliary domains through optimal knowledge transfer

DL-MD-OKT: deep learning-based prediction model for cross-domain recommendation with multi-auxiliary domains through optimal knowledge transfer

Fuzzy logic controller of a step-up boost converter applied to a photovoltaic system

the constantly increasing global energy need and the polluting nature of fossil energies have increased the interest in the development of renewable energies. Among them, photovoltaic energy. The function of a photovoltaic (PV) system is to ensure the conversion of solar energy into electrical energy and the conditioning of this energy in order to adapt it to various needs. The performance of a PV system depends essentially on the quality of the conditioning of the energy, which allows the optimal transfer of the energy of the PV generator, and the management of the energy produced to meet energy needs by incorporating of converters. In this article, we present an intelligent approach to improve and optimize the performance of a photovoltaic system, by the fuzzy MPPT control. Our system consists of a photovoltaic panel, a Boost-type DC-DC converter con-sidered as an adaptation stage between the PV and the load. The IC technique was compared with FLC to evaluate the best and most accurate controller for MPPT. The results suggest that the use of FLC could improve the MPPT and increase the sTableility of the PV system. System modeling and simulation performed with Matlab/Simulink.

Methods for performance optimization of ultra-thin heat pipes with composited wick

Ultra-thin heat pipes are extensively utilized in heat dissipation systems for portable electronic devices, and their thermal performance is mainly affected by the wick. A mathematical model of the ultra-thin heat pipe with composited wick of the copper mesh and copper fiber bundle was developed. Based on the mathematical model, the composited wick was optimized to enhance the maximum heat transfer capacity. The optimization results indicated that the heat pipe achieved optimal heat transfer performance with a single layer of copper mesh, a 0.75 mm width copper fiber bundle, and zero position. The optimized wick structure enhanced the maximum heat transfer capacity of the heat pipe by 40.03 % compared to its capacity before optimization.

Constrained multi-objective optimization assisted by convergence and diversity auxiliary tasks

In the field of constrained multi-objective optimization, constructing auxiliary tasks can guide the algorithm to achieve efficient search. Different forms of auxiliary tasks have their own advantages, and a reasonable combination can effectively improve the performance of the algorithm. Inspired by this, a Constrained Multi-objective Optimization Evolutionary Algorithm based on Convergence and Diversity auxiliary Tasks (CMOEA-CDT) is proposed. This algorithm achieves efficient search through simultaneous optimization and knowledge transfer of the main task, convergence auxiliary task, and diversity auxiliary task. Specifically, the main task is to find feasible Pareto front, which improves the global exploration and local exploitation of the algorithm through knowledge transfer from the convergence and diversity auxiliary tasks. In addition, the convergence auxiliary task helps the main task population traverse infeasible obstacles by ignoring constraints to achieve global search. The diversity auxiliary task aims to provide local diversity to the regions around the main task population to exploit promising search regions. The convergence and diversity of the algorithm are significantly improved by knowledge transfer between the convergence auxiliary task, diversity auxiliary task, and main task. CMOEA-CDT is compared with five state-of-the-art constrained multi-objective evolutionary optimization algorithms on 37 benchmark problems and a disc brake engineering design problem. The experimental results indicate that the proposed CMOEA-CDT respectively obtains 19 and 20 best results on the two indicators, and achieves the best performance on disc brake engineering design problem.

Misalignment analysis of WPT level 3/Z2-class of CirPT with DDPR and CirPR for EVs stationary charging.

Future inductive charging ports must possess the capability to charge any electric vehicle (EV), irrespective of the specific coil architecture it is equipped with. This study examines the misalignment scenarios of the global circular pad at transmitter side (CirPT) with circular receiver pad (CirPR) and a double-D receiver pad (DDPR). The CirPT, CirPR, and DDPR configurations for WPT3 (11.1kW) with ground clearance meeting the Z2-class specifications and above ground surface installation are built by utilizing circuit analysis and 3D-finite element simulations, as outlined by the Society of Automotive Engineering (SAE) J2954 standard. The simulated designs are employed to determine the frequency (f) and the compensating network components (CNCs) required to achieve optimal power transfer efficiency while maintaining nominal power levels. The analysis of misalignment scenarios involves examining various performance factors, including coupling coefficient (k), transmission power (Po), efficiency (η), and leakage electromagnetic fields (EMFs). These factors are assessed under conditions of ideal alignment, as well as various linear and angular misalignments within the inductive charging system. The results demonstrate that both the CirPR and DDPR configurations can successfully interface with the CirPT to provide the required Po to the EV battery with commendable efficiency. In perfect alignment, the efficiencies are 95.10% for the CirPT-CirPR model and 91.60% for the CirPT-DDPR model. In maximum misalignment, the efficiencies are 87.10% for the CirPT-CirPR model and 89.50% for the CirPT-DDPR model, all exceeding the acceptable threshold of 80%.

Inverse stochastic resonance in adaptive small-world neural networks.

Inverse stochastic resonance (ISR) is a counterintuitive phenomenon where noise reduces the oscillation frequency of an oscillator to a minimum occurring at an intermediate noise intensity, and sometimes even to the complete absence of oscillations. In neuroscience, ISR was first experimentally verified with cerebellar Purkinje neurons [Buchin et al., PLOS Comput. Biol. 12, e1005000 (2016)]. These experiments showed that ISR enables a locally optimal information transfer between the input and output spike train of neurons. Subsequent studies have further demonstrated the efficiency of information processing and transfer in neural networks with small-world network topology. We have conducted a numerical investigation into the impact of adaptivity on ISR in a small-world network of noisy FitzHugh-Nagumo (FHN) neurons, operating in a bi-metastable regime consisting of a metastable fixed point and a metastable limit cycle. Our results show that the degree of ISR is highly dependent on the value of the FHN model's timescale separation parameter ε. The network structure undergoes dynamic adaptation via mechanisms of either spike-time-dependent plasticity (STDP) with potentiation-/depression-domination parameter P or homeostatic structural plasticity (HSP) with rewiring frequency F. We demonstrate that both STDP and HSP amplify the effect of ISR when ε lies within the bi-stability region of FHN neurons. Specifically, at larger values of ε within the bi-stability regime, higher rewiring frequencies F are observed to enhance ISR at intermediate (weak) synaptic noise intensities, while values of P consistent with depression-domination (potentiation-domination) consistently enhance (deteriorate) ISR. Moreover, although STDP and HSP control parameters may jointly enhance ISR, P has a greater impact on improving ISR compared to F. Our findings inform future ISR enhancement strategies in noisy artificial neural circuits, aiming to optimize local information transfer between input and output spike trains in neuromorphic systems and prompt venues for experiments in neural networks.

Synergistic effects of magnetic fields and Y-obstacles on a nanofluid-based split lid-driven thermal system

This study investigates the complex hydrothermal behavior in a novel split-driven square cavity filled with CuO-water nanofluid and featuring a Y-shaped obstacle. The research explores the interplay among mixed convection, magnetohydrodynamics (MHD), and geometric factors in a previously unexamined configuration. The upper wall is split into two isothermally heated, translating sections, while the bottom wall and Y-shaped obstacle provide cooling boundaries. Using finite element analysis, we examine the effects of Reynolds number (Re = 10-200), Rayleigh number (Ra = 103-106), Hartmann number (Ha = 0-70), and magnetic field inclination (λ = 0-150°) on flow patterns, heat transfer, and entropy generation. Energy flux vectors are utilized to analyze thermal energy transport dynamics. Key findings are as follows. (1) Increasing Re enhances fluid mixing, resulting in up to a 65% increase in the average Nusselt number (Nu). (2) Nu peaks at Ra ≈ 105, then slightly decreases due to complex force interactions. (3) Increasing Ha suppresses convection, reducing Nu by up to 30%. (4) Optimal heat transfer occurs at λ ≈ 75°. (5) The Y-shaped obstacle enhances heat transfer by up to 30%. These results provide insights for optimizing thermal management in applications requiring precise temperature control, potentially improving energy efficiency in advanced heat transfer systems.

Optimal low-thrust orbit transfers connecting Gateway with Earth and Moon

Gateway will represent a primary logistic infrastructure in cislunar space. The identification of efficient orbit transfers capable of connecting Earth, Moon, and Gateway paves the way for enabling refurbishment, servicing, and utilization of this orbiting platform. This study is devoted to determining two-way minimum-time low-thrust orbit transfers that connect both Earth and Moon to Gateway. Backward time propagation is proposed as a very convenient option for trajectories that approach and rendezvous with Gateway, and a unified formulation is introduced for minimum-time orbit transfers, using either forward or backward propagation. Two-way transfers between Gateway and a specified low-altitude lunar orbit are first determined, using an indirect heuristic method, which employs the necessary conditions for optimality and a heuristic algorithm. Second, two-way orbit transfers that connect Earth and Gateway are addressed. Because these trajectories exist under the influence of two major attracting bodies, the underlying optimal control problem is formulated as a multi-arc trajectory optimization problem, involving three different representations for the spacecraft state. Multi-arc optimal control problems are associated with several corner conditions to be enforced at the junction time that separates distinct arcs. However, these conditions are shown to be solvable sequentially for the problem at hand, leveraging implicit costate transformation. This implies that the multi-arc problem has a set of unknown quantities with the same size as that of a single-arc optimal control problem, with apparent advantages of a computational nature. The indirect heuristic method is also applied in this second mission scenario. Low-thrust orbit dynamics is propagated in a high-fidelity dynamical framework, with the use of planetary ephemeris and the inclusion of the simultaneous gravitational action of Sun, Earth, and Moon, along the entire transfer paths, in all cases. The numerical results unequivocally prove that the methodology developed in this research is effective for determining two-way minimum-time low-thrust orbit transfers connecting Earth, Moon, and Gateway.

PSO-FDM (Particle Swarm Optimization-Finite Difference Method)-Based Simulation Model of Temperature and Velocity of Full-Scale Continuous Annealing Furnace

Improving the accuracy of the temperature field prediction model for continuous annealing line strips and enhancing the model’s adaptability to full-size strips are key technical challenges in continuous annealing lines. This paper developed a continuous annealing temperature prediction model based on a variable step-size strategy for the heating section, even-heat section, slow-cooling section, and fast-cooling section of the continuous annealing line. To improve the prediction accuracy for different strip sizes, the PSO optimization algorithm was employed to determine the optimal heat transfer coefficient for each strip size. Additionally, due to the limited production of certain strip gauges, providing insufficient data for optimization, this study introduces a combined file approach to address gauge vacancies. The experimental results indicate that the optimized model with variable step size can control the absolute prediction error to less than 4 °C, improving prediction accuracy by 61.9% and prediction speed by 26.8% compared to the traditional equal-step prediction model. This study verified that the merger method is effective for addressing side gauge vacancies, while the proposed method is suitable for resolving middle gauge vacancies. The main technical contribution of this study is the establishment of a high-precision prediction model for continuous annealing temperature of variable step length strips, ensuring high temperature control accuracy for full-gauge strips when passing through the continuous annealing production line.