Marina Ladonkina¹, Viktoriia Podryga^1,*, Yury Poveshchenko¹, Haochen Zhang²

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1789-1809, 2025, DOI:10.32604/fhmt.2025.066953 - 31 December 2025

Abstract The work presents new methods for selecting adaptive artificial viscosity (AAV) in iterative algorithms of completely conservative difference schemes (CCDS) used to solve gas dynamics equations in Euler variables. These methods allow to effectively suppress oscillations, including in velocity profiles, as well as computational instabilities in modeling gas-dynamic processes described by hyperbolic equations. The methods can be applied both in explicit and implicit (method of separate sweeps) iterative processes in numerical modeling of gas dynamics in the presence of heat and mass transfer, as well as in solving problems of magnetohydrodynamics and computational astrophysics. In… More >

Heng Cheng¹, Yichen Yang¹, Yumin Cheng^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.145, No.3, pp. 2853-2894, 2025, DOI:10.32604/cmes.2025.073178 - 23 December 2025

Abstract The element-free Galerkin (EFG) method, which constructs shape functions via moving least squares (MLS) approximation, represents a fundamental and widely studied meshless method in numerical computation. Although it achieves high computational accuracy, the shape functions are more complex than those in the conventional finite element method (FEM), resulting in great computational requirements. Therefore, improving the computational efficiency of the EFG method represents an important research direction. This paper systematically reviews significant contributions from domestic and international scholars in advancing the EFG method. Including the improved element-free Galerkin (IEFG) method, various interpolating EFG methods, four distinct More >

Shuxin Tan¹, Wei Yan², Lei Zhao¹, Xianglin Zhang^3,*, Ziqiang Man², Yu Lu², Teng Liu², Gaoyue Zhong², Weiqun Liu², Linjun Shi³

Energy Engineering, Vol.122, No.12, pp. 5175-5197, 2025, DOI:10.32604/ee.2025.068692 - 27 November 2025

Abstract The integration of large-scale renewable energy introduces frequency instability challenges due to inherent intermittency. While doubly-fed pumped storage units (DFPSUs) offer frequency regulation potential in pumping mode, conventional strategies fail to address hydraulic-mechanical coupling dynamics and operational constraints, limiting their effectiveness. This paper presents an innovative primary frequency control strategy for double-fed pumped storage units (DFPSUs) operating in pumping mode, integrating an adaptive parameter calculation method. This method is constrained by operational speed and power limits, addressing key performance factors. A dynamic model that incorporates the reversible pump-turbine characteristics is developed to translate frequency deviations… More >

Qiang Ma^1,2,3,4, Zepeng Li^1,2, Kai Yang^1,2,*, Shaofeng Zhang^1,2, Zhuopei Wei^1,2

Structural Durability & Health Monitoring, Vol.19, No.6, pp. 1607-1634, 2025, DOI:10.32604/sdhm.2025.069876 - 17 November 2025

Abstract Effective fault identification is crucial for bearings, which are critical components of mechanical systems and play a pivotal role in ensuring overall safety and operational efficiency. Bearings operate under variable service conditions, and their diagnostic environments are complex and dynamic. In the process of bearing diagnosis, fault datasets are relatively scarce compared with datasets representing normal operating conditions. These challenges frequently cause the practicality of fault detection to decline, the extraction of fault features to be incomplete, and the diagnostic accuracy of many existing models to decrease. In this work, a transfer-learning framework, designated DSCNN-HA-TL,… More >

Mairaj Bibi¹, Muhammad Shoaib Arif ², Yasir Nawaz³, Nabil Kerdid^4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.145, No.1, pp. 537-569, 2025, DOI:10.32604/cmes.2025.070362 - 30 October 2025

Abstract This study develops a high-order computational scheme for analyzing unsteady tangent hyperbolic fluid flow with variable thermal conductivity, thermal radiation, and coupled heat and mass transfer effects. A modified two-stage Exponential Time Integrator is introduced for temporal discretization, providing second-order accuracy in time. A compact finite difference method is employed for spatial discretization, yielding sixth-order accuracy at most grid points. The proposed framework ensures numerical stability and convergence when solving stiff, nonlinear parabolic systems arising in fluid flow and heat transfer problems. The novelty of the work lies in combining exponential integrator schemes with compact… More >

Huazhe Wan¹, Wenying Huang², Wen Zhang², Chang Hu^2,*

International Journal of Mental Health Promotion, Vol.27, No.10, pp. 1611-1626, 2025, DOI:10.32604/ijmhp.2025.070457 - 31 October 2025

Abstract Background: Social anxiety is prevalent among adolescents and severely impacts their mental health and social functioning. This study aims to explore the underlying mechanisms and subgroup differences in adolescent social anxiety to provide a theoretical basis for targeted interventions. Methods: 3025 Chinese adolescents (Mean_age = 13.91 ± 1.60 years; 47% male) completed self-report measures of physical activity, core self-evaluation, and social anxiety. Variable-centered analyses employed PROCESS Model 4 with 5000 bootstrap samples; covariates were gender, grade, and place of residence. Person-centered analyses used latent profile analysis in Mplus 8.3 to identify subgroups based on social anxiety… More >

Jinyu Guo^*, Xingxu Zhu, Zezhong Liu, Cuiping Li

Energy Engineering, Vol.122, No.10, pp. 3961-3983, 2025, DOI:10.32604/ee.2025.067811 - 30 September 2025

Abstract In high-renewable-energy power systems, the demand for fast-responding capabilities is growing. To address the limitations of conventional closed-loop frequency control, where the integral coefficient cannot dynamically adjust the frequency regulation command based on the state of charge (SoC) of energy storage units, this paper proposes a secondary frequency regulation control strategy based on variable integral coefficients for multiple energy storage units. First, a power-uniform controller is designed to ensure that thermal power units gradually take on more regulation power during the frequency regulation process. Next, a control framework based on variable integral coefficients is proposed… More >

Xiaoyang Wu¹, Wenchao Han², Min Kuang^2,*, Xinqi Wang², Wenhao Xie²

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.9, pp. 2201-2223, 2025, DOI:10.32604/fdmp.2025.067081 - 30 September 2025

Abstract The dynamic behavior of high-speed craft navigating through variable sea states plays a pivotal role in ensuring maritime safety. However, many existing simulation approaches rely on linear or overly simplified representations of the marine environment, thereby limiting the fidelity of motion predictions. This study explores the motion characteristics of a 4.5-t high-speed vessel by conducting fully coupled numerical simulations using the STAR-CCM+ software. The analysis considers both calm and varying sea conditions, incorporating fluctuations in wave height, wavelength, and wind speed to reflect more realistic operating scenarios. Simulation results reveal that the vessel’s hydrodynamic response… More >

Yi Guan¹, Pengpeng Zhi^2,3,*, Zhonglai Wang^1,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.144, No.3, pp. 3343-3368, 2025, DOI:10.32604/cmes.2025.069515 - 30 September 2025

Abstract Variable-fidelity (VF) surrogate models have received increasing attention in engineering design optimization as they can approximate expensive high-fidelity (HF) simulations with reduced computational power. A key challenge to building a VF model is devising an adaptive model updating strategy that jointly selects additional low-fidelity (LF) and/or HF samples. The additional samples must enhance the model accuracy while maximizing the computational efficiency. We propose ISMA-VFEEI, a global optimization framework that integrates an Improved Slime-Mould Algorithm (ISMA) and a Variable-Fidelity Expected Extension Improvement (VFEEI) learning function to construct a VF surrogate model efficiently. First, A cost-aware VFEEI More >

Jiangbo Wu¹, Siyi Sun¹, Xiaoze Du^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.8, pp. 1789-1807, 2025, DOI:10.32604/fdmp.2025.064254 - 12 September 2025

Abstract This study explores the aerodynamic performance and flow field characteristics of supercritical carbon dioxide (sCO₂) centrifugal compressors under varying operating conditions. In particular, the Sandia main compressor impeller model is used as a reference system. Through three-dimensional numerical simulations, we examine the Mach number distribution, temperature field, blade pressure pulsation spectra, and velocity field evolution, and identify accordingly the operating boundaries ensuring stability and the mechanisms responsible for performance degradation. Findings indicate a stable operating range for mass flow rate between 0.74 and 3.74 kg/s. At the lower limit (0.74 kg/s), the maximum Mach number within… More >