KL Vasudev¹, Manish Pandey², Jaan H. Pu^3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.7, pp. 1545-1569, 2025, DOI:10.32604/fdmp.2025.065289 - 31 July 2025

Abstract This study presents a comparative analysis of optimisation strategies for designing hull shapes of Autonomous Underwater Vehicles (AUVs), paying special attention to drag, lift-to-drag ratio, and delivered power. A fully integrated optimisation framework is developed accordingly, combining a single-objective Genetic Algorithm (GA) for design parameter generation, Computer-Aided Geometric Design (CAGD) for the creation of hull geometries and associated fluid domains, and a Reynolds-Averaged Navier–Stokes (RANS) solver for evaluating hydrodynamic performance metrics. This unified approach eliminates manual intervention, enabling automated determination of optimal hull configurations. Three distinct optimisation problems are addressed using the proposed methodology. First,… More >

Yang Sun¹, Runze Yang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.7, pp. 1737-1751, 2025, DOI:10.32604/fdmp.2025.063103 - 31 July 2025

Abstract The intake system of a racing engine plays a crucial role in determining its performance, particularly in terms of volumetric efficiency, power output, and throttle response. According to Formula Society of Automotive Engineers (FSAE) regulations, the engine intake system must incorporate a 20 mm diameter flow-limiting valve within the intake manifold. This restriction significantly reduces the airflow into the engine, leading to a substantial drop in power output. To mitigate this limitation, the intake system requires a redesign. In this study, theoretical calculations and one-dimensional thermodynamic simulations are employed to determine the optimal parameters for… More >

Sergio Cassese¹, Riccardo Guida^2,3,*, Daniele Trincone¹, Stefano Mungiguerra¹, Raffaele Savino¹

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.6, pp. 1299-1337, 2025, DOI:10.32604/fdmp.2025.065605 - 30 June 2025

Abstract Robust numerical tools are essential for enabling the use of hybrid rocket engines (HREs) in future space applications. In this context, Computational Fluid Dynamics (CFD) transient simulations can be employed to analyse and predict relevant fluid dynamics phenomena within the thrust chamber of small-scale HREs. This work applies such techniques to investigate two unexpected behaviours observed in a 10 N-class hydrogen peroxide-based hybrid thruster: an uneven regression rate during High-Density Polyethylene (HDPE) and Acrylonitrile Butadiene Styrene (ABS) fuel tests, and non-negligible axial consumption in the ABS test case. The present study seeks to identify their… More >

Basima Salman Khalaf^*, Abeer H. Falih, Basim Freegah

Frontiers in Heat and Mass Transfer, Vol.23, No.3, pp. 943-956, 2025, DOI:10.32604/fhmt.2025.065366 - 30 June 2025

Abstract The main purpose of this research is to optimize the hydrothermal performance of a dimpled tube by augmenting the surface area for heat transmission and thermal layer cracking. To achieve that, the impact of different dimple diameters and their distribution along the dimpled tube was investigated numerically using the ANSYS Fluent 2022 R1 software by considering two models, A and B. Both models consist of three regions; the first, second, and third have dimple diameters of 3, 2, & 1 mm, respectively. Model A included an in-line dimple arrangement, while model B involved a staggered… More >

Shiyao Peng¹, Hanwen Zhang¹, Chong Chai¹, Shilong Xue², Xiaobin Zhang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.5, pp. 1099-1112, 2025, DOI:10.32604/fdmp.2025.060452 - 30 May 2025

Abstract The diffusion of hydrogen-blended natural gas (HBNG) from buried pipelines in the event of a leak is typically influenced by soil properties, including porosity, particle size, temperature distribution, relative humidity, and the depth of the pipeline. This study models the soil as an isotropic porous medium and employs a CFD-based numerical framework to simulate gas propagation, accounting for the coupled effects of soil temperature and humidity. The model is rigorously validated against experimental data on natural gas diffusion in soil. It is then used to explore the impact of relevant parameters on the diffusion behavior… More >

Rodolfo V. C. Ramalho¹, Vitoria B. Portilho¹, Davi E. S. Souza¹, Gilton C. A. Furtado¹, Natália M. Graças², Manoel J. S. Sena², Cláudio J. C. Blanco², André L. Amarante Mesquita^1,*

Energy Engineering, Vol.122, No.6, pp. 2197-2213, 2025, DOI:10.32604/ee.2025.064196 - 29 May 2025

Abstract Despite significant Brazilian social programs to expand energy access, approximately one million people in rural Amazonia still lack electricity. Moreover, the existing rural electricity grid in the region is inadequate for supporting efficient small-scale production systems due to both the poor quality and high cost of supplied energy. In parallel, traditional wooden bridges in the Amazon have been progressively replaced by more durable concrete structures in recent years. In this context, this study explores the application of very low-head hydropower installations in the Amazon, focusing on integrating axial-flow turbines beneath small concrete bridges. The methodology… More > Graphic Abstract

Anna Chiara Uggenti¹, Giorgio Rech², Raffaella Gerboni^2,*, Gianmario Ledda², Amedeo Aliberti¹, Claudia Vivalda³, Emanuela Bruno², Andrea Carpignano²

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.4, pp. 757-782, 2025, DOI:10.32604/fdmp.2025.062347 - 06 May 2025

Abstract The paper presents an innovative approach to studying the reuse of a decommissioned natural gas production platform for the seasonal storage and extraction of a hydrogen-methane (H₂-CH₄) mixture from a depleted reservoir. The reuse plan involves removing outdated equipment from the platform’s decks while retaining essential components such as wellheads and separators. Exploiting a depleted reservoir for the injection of an H₂-CH₄ mixture requires a thorough understanding of its specific characteristics. This paper focuses on the engineering approach adopted in the basic design phase for such a conversion, providing recommendations and HSE guidelines. Given the hazardous… More >

Meng Zhao¹, Jiaao Liu², Yudi Liu³, Zhengwei Long^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.142, No.2, pp. 1545-1564, 2025, DOI:10.32604/cmes.2025.058773 - 27 January 2025

Abstract Computational Fluids Dynamics (CFD) simulations are essential for optimizing the design of a cockpit’s internal environment, but the complex geometric models consume a significant amount of computational resources and time. Arbitrary simplification of geometric models may result in inaccurate calculations of physical fields. To address this issue, this study establishes a geometric model simplification strategy and successfully applies it to a cockpit. The implementation of the whole approach is divided into three steps, summarized in three methods, namely Sensitivity Analysis Method (SAM), Detail Suppression Method (DSM), and Evaluation Standards Method (ESM). Sensitivity analysis of the More >

Lihui Ma¹, Wei Li¹, Yuanyuan Wang¹, Pan Zhang¹, Lina Wang¹, Xinying Liu¹, Meiqin Dong², Xuewen Cao², Jiang Bian^3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.1, pp. 107-119, 2025, DOI:10.32604/fdmp.2024.058295 - 24 January 2025

Abstract Gas-liquid flow (GLF), especially slug and annular flows in oil and gas gathering and transportation pipelines, become particularly complex inside elbows and can easily exacerbate pipeline corrosion and damage. In this study, FLUENT was used to conduct 3D simulations of slug and annular flow in elbows for different velocities to assess the ensuing changes in terms of pressure. In particular, the multifluid VOF (Volume of Fraction) model was chosen. The results indicate that under both slug and annular flow conditions, the pressure inside the elbow is lower than the outside. As the superficial velocity More >

Shande Li¹, Wen’an Zhong¹, Shaoxing Yu¹, Hao Wang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.1, pp. 179-204, 2025, DOI:10.32604/fdmp.2024.056228 - 24 January 2025

Abstract This paper aims to numerically explore the characteristics of unsteady cavitating flow around a NACA0015 hydrofoil, with a focus on vorticity attributes. The simulation utilizes a homogeneous mixture model coupled with a filter-based density correction turbulence model and a modified Zwart cavitation model. The study investigates the dynamic cavitation features of the thermal fluid around the hydrofoil at various incoming flow velocities. It systematically elucidates the evolution of cavitation and vortex dynamics corresponding to each velocity condition. The results indicate that with increasing incoming flow velocity, distinct cavitation processes take place in the flow field. More >