Mengjie Wang¹, Jingfa Li^2,*, Bo Yu², Nianrong Wang³, Xiaofeng Wang³, Tao Hu⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.12, pp. 3055-3072, 2025, DOI:10.32604/fdmp.2025.071675 - 31 December 2025

Abstract The adaptation of existing natural gas pipelines for hydrogen transportation has attracted increasing attention in recent years. Yet, whether hydrogen and natural gas stratify under static conditions remains a subject of debate, and experimental evidence is still limited. This study presents an experimental investigation of the concentration distribution of hydrogen–natural gas mixtures under static conditions. Hydrogen concentration was measured using a KTL-2000M-H hydrogen analyzer, with a measurement range of 0–30% (by volume), an accuracy of 1% full scale (FS), and a resolution of 0.01%. Experiments were conducted in a 300 cm riser, filled with uniformly… More >

Hao Tang^1,2,3, Jianchang Yang^1,2,3, Yunxin Zhou^1,2,3, Jianxin Xu^1,2,3,*, Hua Wang^1,2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.7, pp. 1571-1600, 2025, DOI:10.32604/fdmp.2025.063741 - 31 July 2025

Abstract This research explores the characteristics of boiling in inclined pipes, a domain of great importance in engineering. Employing an experimental visualization technique, the boiling dynamics of deionized water are examined at varying inclination angles, paying special attention to the emerging flow patterns. The findings demonstrate that the inclination angle significantly impacts flow pattern transitions within the 0° to 90° range. As the heat flux rises, bubbles form in the liquid. The liquid’s inertia extends the bubble-wall contact time, thereby delaying the onset of bulk bubble flow. Beyond a 90° inclination, however, the patterning behavior is… More > Graphic Abstract

Yangyang Cao, Jiye Zhang^*, Jiawei Shi, Yao Zhang

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.5, pp. 1079-1098, 2025, DOI:10.32604/fdmp.2025.060429 - 30 May 2025

Abstract The pantograph area is a critical source of aerodynamic noise in high-speed trains, generating noise both directly and through its cavity, a factor that warrants considerable attention. One effective method for reducing aerodynamic noise within the pantograph cavity involves the introduction of a jet at the leading edge of the cavity. This study investigates the mechanisms driving cavity aerodynamic noise under varying jet velocities, using Improved Delayed Detached Eddy Simulation (IDDES) and Ffowcs Williams-Hawkings (FW-H) equations. The numerical simulations reveal that an increase in jet velocity results in a higher elevation of the shear layer… More >

Ikram Mostefa Tounsi^1,*, Mustapha Boussoufi¹, Amina Sabeur¹, Mohammed El Ganaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2603-2616, 2024, DOI:10.32604/fdmp.2024.050641 - 28 October 2024

Abstract This study aims to optimize the influence of the inlet inclination angle on the Indoor Air Quality (IAQ), heat, and temperature distribution in mixed convection within a two-dimensional square cavity filled with an air-CO₂ mixture. The air-CO₂ mixture enters the cavity through two inlet openings positioned at the top wall, which is set at the ambient temperature (T_C). Three values of the Reynolds numbers, ranging from 1000 to 2000, are considered, while the Prandtl number is kept constant (Pr = 0.71). The temperature distribution and streamlines are shown for Rayleigh number (Ra) equal to 10⁴, three inlet More >

Zhigang Wang, Bin Zheng, Peidong Zhao, Baoli Wang, Fanyan Meng, Wenke Xu, Jian Meng^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.2, pp. 365-382, 2024, DOI:10.32604/fdmp.2023.030302 - 14 December 2023

Abstract Heavy-fuel engines are widely used in UAVs (Unmanned Autonomous Vehicles) because of their reliability and high-power density. In this study, a combustion model for an in-cylinder direct injection engine has been implemented using the AVL FIRE software. The effects of the angle of nozzle inclination on fuel evaporation, mixture distribution, and combustion in the engine cylinder have been systematically studied at 5500 r/min and considering full load cruise conditions. According to the results, as the angle of nozzle inclination increases, the maximum combustion explosion pressure in the cylinder first increases and then it decreases. When… More > Graphic Abstract

M’Barka Mourabit^1,*, Meryam Meknassi², Soukaina Fekkar¹, Soumia Mordane¹, Hicham Rouijaa³, El Alami Semma⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1753-1774, 2023, DOI:10.32604/fdmp.2023.025739 - 08 March 2023

Abstract

The effect of the tilt angle on mixed convection and related heat transfer in a “T” shaped double enclosure with four heated obstacles on the bottom surface is numerically investigated. The considered obstacles are constantly kept at a relatively high (fixed) temperature, while the cavity’s upper wall is cooled. The finite volume approach is used to solve the mass, momentum, and energy equations with the SIMPLEC algorithm being exploited to deal with the pressure-velocity coupling. Emphasis is put on the influence of the tilt angle on the solution symmetry, flow structure, and heat exchange through the

… More > Graphic Abstract

Olanrewaju M. Oyewola^a,b,*, Samuel I. Afolabi^b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.20

Abstract This paper investigates numerically the problem of convective heat transfer and entropy generation by two adiabatic obstacles positioned inside a square cavity heated at the left wall and cooled on the right wall while horizontal walls are adiabatic. The inclination angle of the cavity orientation investigated are 30, 60 and 90 degrees. Rayleigh numbers ranging from 103 to 106 were calculated for two vertical obstacles. The method of Galerkin finite element was employed to solve the conservation equations of mass, momentum and energy. The cavity is assumed to be filled with air with Prandtl number More >

Khaled Said^*, Ahmed Ouadha, Amina Sabeur

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1619-1629, 2022, DOI:10.32604/fdmp.2022.022220 - 27 June 2022

Abstract The present study deals with double-diffusive convection within a two-dimensional inclined cavity filled with an air-CO₂ binary gas mixture. The left and the right vertical walls are differentially heated and subjected to different locations of (CO₂) contaminants to allow for the variation of the buoyancy strength (N). However, the horizontal walls are assumed adiabatic. The simulations are conducted using the finite volume method to solve the conservation equations of continuity, momentum, energy, and species transport. Good agreement with other numerical results in the literature is obtained. The effect of multiple parameters, namely, buoyancy ratio (N), thermal More >

Zhibin Zhang^1,2, Yongjun Gong^1,*, Liping Zhang³, Min Xv², Gaofeng Shang⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1363-1371, 2022, DOI:10.32604/fdmp.2022.019746 - 27 May 2022

Abstract The effects of oblique submerged scouring jets on sand beds with various particle sizes have been studied experimentally. In particular, a total of 25 experiments have been carried out to explore the influences of the jet angle and application time on the considered submerged sand beds. Test results conducted with a specially-designed device have shown that the scouring efficiency attains a maximum when the inclination angle is in the range between 15° and 20° and then it decreases when the inclination angle becomes higher. More >

Yushan Liu^1,2, Yubin Su³, Zhenhua Wu⁴, Wei Luo^1,2, Ruiquan Liao^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 475-488, 2020, DOI:10.32604/fdmp.2020.08896 - 25 May 2020

Abstract The lifting efficiency and stability of gas lift well are affected by the socalled slippage-loss effect in gas-liquid two-phase flow. The existing studies on this subject have generally been based on vertical and horizontal wells. Only a few of them have considered inclined pipes. In the present work a new focused study is presented along these lines. More specifically, we use the non-slip pressure drop model with Flanigan’s fluctuation correction coefficient formula (together with the parameters of slippage density, slippage pressure drop and slippage ratio) to analyze the influence of the inclination angle on slippage… More >