Documents published in Scipedia

• Impulsive Fractional Boundary Value Problems Involving Volterra–Fredholm Integral Operators

  M. Balti, M. Hamood

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (3), 47

  
  

  Abstract

  This article investigates a class of nonlinear impulsive fractional integrodifferential equations involving Riemann–Liouville fractional derivatives and integral boundary conditions. The model incorporates Volterra– Fredholm integral operators to represent both memory effects and nonlocal interactions in systems experiencing impulsive changes. To address the analytical challenges posed by the nonlocal and impulsive features, we develop a novel hybrid fixed-point approach that combines the Banach contraction principle with Krasnoselskii’s theorem in Banach spaces. We establish rigorous existence and uniqueness results under suitable conditions. A detailed example is provided to demonstrate the effectiveness and applicability of the proposed method.OPEN ACCESS Received: 02/05/2025 Accepted: 27/06/2025 Published: 15/08/2025

  Abstract
  This article investigates a class of nonlinear impulsive fractional integrodifferential equations involving Riemann–Liouville fractional derivatives and integral boundary [...]

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• Optical Soliton Dynamics in Nonlinear Evolution Equations: Modified Kawahara and Modified Benjamin Bona Mahony Models

  H. Mehmood, D. Baleanu, M. Abbas, M. Yousif, P. Mohammed, F. Abdullah, I. Ibrahim

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (3), 45

  
  

  Abstract

  This paper explores the dynamic behavior of optical soliton solutions for the modified Kawahara (mK) equation and the modified BenjaminBona-Mahony (mBBM) equation, two significant nonlinear evolution equations. Using an advanced analytical approach, a diverse set of soliton solutions is derived, including bell-shaped, anti-bell-shaped, W-shaped, M-shaped, and periodic waveforms. These solutions unveil the intricate nonlinear dynamics underlying the equations. The robustness of the method is demonstrated through comprehensive 2D, 3D, and contour visualizations, offering clear insights into the physical significance of the solitons. The study enhances the existing catalog of soliton solutions, contributing to a deeper understanding of nonlinear wave propagation and its potential applications in fields such as optical communication and fluid dynamics.OPEN ACCESS Received: 06/05/2025 Accepted: 09/06/2025 Published: 15/08/2025

  Abstract
  This paper explores the dynamic behavior of optical soliton solutions for the modified Kawahara (mK) equation and the modified BenjaminBona-Mahony (mBBM) equation, two significant [...]

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• Optimization of EV and Green Source Fed Five-Level UPQC for Power Quality and Energy Management Using Fennec Fox Algorithm

  P. Balachandran, G. Kalpana, V. Babyshalini, K. Srilakshmi, S. Singh

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (3), 44

  
  

  Abstract

  Distribution systems have been significantly impacted in the present scenario by incorporating solar and wind power electronic devices. This work designs the synchronous reference frame theory (SRFT) based fivelevel cascade H-bridge unified power quality conditioner (UPQC) by optimizing the weights and bias values of the neural network controller (NNC) and the filter parameters using the Fennec fox optimization algorithm (FFOA). The primary goal is to efficiently tackle the power quality difficulties, including voltage distortions, direct current (DC) link capacitor voltage (DLCV) balancing, and to reduce the source current total harmonic distortion (THD) of the system connected to the grid that integrates wind energy system (WES) and solar system, including electric vehicle (EVs) along with battery energy storage system (BESS) which is denoted as (5LU-SWBEV). The study also intends to use a Fuzzy logic controller (FLC) regulation to control the flow of power between the grid, battery storage, EV and renewable sources. However, this facilitates the management of power transfer between solar/wind/battery and the grid and between EVs and consumer loads. Additionally, this integration contributes to a consistent electricity supply, effective demand fulfillment, and efficient use of generated power. The study shows that the optimal UPQC combined with FLC-based power flow management can handle power quality (PQ) issues and accomplish suitable and efficient power sharing.OPEN ACCESS Received: 13/04/2025 Accepted: 09/06/2025 Published: 15/08/2025

  Abstract
  Distribution systems have been significantly impacted in the present scenario by incorporating solar and wind power electronic devices. This work designs the synchronous reference [...]

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• Understanding Aero- and Hydrodynamics of Sailing - The Key to improve Performance

  M. Fischer

  Marine 2025.

  
  

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• Mechanism of lift/thrust generation and vortex dynamics in biomimetic flying and swimming

  W. Huang

  Marine 2025.

  
  

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• On the Challenges of Verification Exercises of Viscous Flow Simulations

  L. Eça

  Marine 2025.

  
  

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• Finite Element Modeling and Construction Aspects of Masonry Walls: An Overview

  A. Al-Fakih

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (3), 43

  
  

  Abstract

  Masonry walls are a cornerstone of building construction worldwide, providing both structural and non-structural functions in diverse settings. Yet, masonry’s inherent heterogeneity, arising from variations in units, mortar joints, and interfaces, presents significant challenges in accurately predicting its performance under service and extreme loads. This review focuses on two complementary perspectives: the construction aspects of various masonry wall systems (including infill, unreinforced, cavity, confined, and interlocking mortarless walls) and the finite element modeling techniques employed to capture masonry’s mechanical behavior. The review found that the wall type has a significant impact on overall structural performance and seismic response. Moreover, it is found that micro-modeling approaches (both detailed and simplified) capture localized stress and strain states in the brick–mortar interface but entail higher computational costs. Macro-modeling provides a more practical, homogenized view for large-scale analysis, treating masonry as an anisotropic continuum. Numerous researchers have demonstrated that well-calibrated models can replicate experimental load-displacement behavior in both compressive and out-of-plane (OOP) bending scenarios. In particular, advanced contact formulations have been developed to address the progressive closure of mortarless joints, while plasticitybased models are widely employed to simulate cracking and crushing in conventional masonry under seismic loading. Collectively, these studies underscore that the choice of modeling strategy depends on the level of detail required, available computational resources, and the target performance metrics. By merging robust numerical methods with proven construction practices, researchers and engineers can better predict masonry’s structural response.OPEN ACCESS Received: 10/05/2025 Accepted: 25/06/2025 Published: 14/07/2025

  Abstract
  Masonry walls are a cornerstone of building construction worldwide, providing both structural and non-structural functions in diverse settings. Yet, masonry’s inherent [...]

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• Free-Strain Consolidation of Soft Ground Improved with Alternating Length PVDs

  B. Lv, C. Zhang, W. Zhou, F. Wang, H. Wang, Z. Chen

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (3), 42

  
  

  Abstract

  In practice, installation of alternating length prefabricated vertical drains (PVDs) cannot only satisfy the strength requirements for the upper soil layer, but also improve the lower soil layer to a certain extent, which is conducive to improving the overall strength and stability of the ground. In this paper, the original three-dimensional consolidation model for alternating length PVDs is simplified into a plane equivalent model, considering only well resistance by the model equivalence technique. Subsequently, a novel semi-analytical solution for soft ground with alternating length PVDs is derived using the boundary transform and local discretization methods. Accuracy analysis of local discretization is conducted to determine the appropriate segment number for PVD-soil interface boundaries. The effectiveness of the proposed solution is demonstrated by comparing the results from numerical analyses. Finally, the influence of the penetration depth of short and long PVDs on the consolidation efficiency is studied. Results show that the installation of alternating length PVDs is more effective compared to the conventional scheme of equal length installation. Both the average degrees of consolidation within and below a design depth for the ground with alternating length PVDs are higher than in the case with equal length PVDs.OPEN ACCESS Received: 20/03/2025 Accepted: 22/05/2025 Published: 14/07/2025

  Abstract
  In practice, installation of alternating length prefabricated vertical drains (PVDs) cannot only satisfy the strength requirements for the upper soil layer, but also improve [...]

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• Fractional Hermite Functions: Power Series Solutions, Rodrigues Representation, and Orthogonality Properties

  M. Awadalla

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (3), 41

  
  

  Abstract

   T his paper develops a rigorous framework for fractional Hermite func tions using Caputo derivatives. We establish three fundamental contribu tions. First, we derive a complete power series solution to the fractional Hermite equation expressed through the basis {xkα}∞ k=0 , proving absolute convergence for all x ∈ C through careful asymptotic analysis of the coefficients. Second, we introduce and characterize both even and odd fractional Hermite functions H(α) n (x), deriving their explicit representa tions, recurrence relations, and a fractional Rodrigues-type formula that generalizes the classical case. Third, we demonstrate their orthogonality properties under the weight function wα(x) = |x|α−1e−|x|2α, obtaining exact normalization constants. The theoretical results are supported by comprehensive graphical analysis showing the systematic deformation of classical Hermite polynomial features as α varies. These developments provide new tools for fractional spectral methods and advance the under standing of orthogonal function systems in fractional calculus.

  Abstract
   T his paper develops a rigorous framework for fractional Hermite func tions using Caputo derivatives. We establish three fundamental contribu tions. First, we derive [...]

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• Coupled Thermal-Structural Analysis and Structural Optimization of the Diaphragm of a Diaphragm Compressor for a Hydrogen Refueling Station

  T. Li, W. Hu, H. Lou, M. Li, Y. Hou, Q. Sun

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (3), 40

  
  

  Abstract

  Diaphragm fatigue fracture stands as one of the primary failure modes in hydrogen refueling station diaphragm compressors, urgently requiring systematic investigation into the mechanical properties and fatigue reliability of diaphragms under actual service conditions. However, due to the complex contact state between the diaphragm and the gas cavity cover plate (gas passage, gas hole)/oil cavity support plate and oil distribution plate (oil passage, oil hole), it is difficult to accurately obtain the stress distribution state of the diaphragm. In this study, we conducted material property experiments on the diaphragm to characterize its constitutive parameters. A refined numerical simulation model of the cover platediaphragm-support plate was established to analyze the mechanical properties of the diaphragm group under different conditions. The influence of diaphragm thickness on stress distribution and fatigue life was also explored. The results indicated that high stress distribution areas were mainly concentrated in the cavity transition zone and in the overlapping area of the diaphragm and gas passage/oil passage. The temperature inside the diaphragm compressor cavity had a significant impact on the stress level of the diaphragm. When the cavity temperature reached 300°C, the maximum von Mises stress reached 1286 MPa. The optimization results of diaphragm thickness indicated that when the diaphragm thickness was within the range of [0.3, 0.5 mm], the diaphragm was at a low stress service level; considering both the fatigue life and deflection performance of the diaphragm, the diaphragm thickness should be selected as thick as possible within the range of [0.3, 0.5 mm]. The numerical simulation model of the diaphragm compressor and the structural optimization design method of the diaphragm proposed in this article have significant engineering implications for improving the fatigue life of diaphragm compressor diaphragms.OPEN ACCESS Received: 02/03/2025 Accepted: 13/05/2025 Published: 14/07/2025

  Abstract
  Diaphragm fatigue fracture stands as one of the primary failure modes in hydrogen refueling station diaphragm compressors, urgently requiring systematic investigation into [...]

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