Nur Husnina Muhamad Zuraidi¹, Sher Afghan Khan^1,*, Abdul Aabid^2,*, Muneer Baig², Istiyaq Mudassir Shaiq³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 807-829, 2023, DOI:10.32604/fdmp.2023.023246

Abstract In this study, a duct is considered and special attention is paid to a passive method for the control of the base pressure relying on the use of a cavity with a variable aspect ratio. The Mach number considered is 1.8, and the area ratio of the duct is 2.56. In particular, two cavities are examined, their sizes being 3:3 and 6:3. The used L/D spans the interval 1–10 while the NPRs (nozzle pressure ratio) range from 2 to 9. The results show that the control becomes effective once the nozzles are correctly expanded or under-expanded. The pressure contours at… More >

Ang Wang^1,*, Hui Wang²

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1293-1306, 2022, DOI:10.32604/fdmp.2022.018561

Abstract This paper investigates the thermal performance of prefabricated exterior walls using the Computational Fluid Dynamics method to reduce energy consumption. The thermal performance of the prefabricated exterior wall was numerically simulated using the software ANSYS Fluent. The composite wall containing the cavity is taken as the research object in this paper after analysis. The simulation suggests that when the cavity thickness is 20 mm and 30 mm, the heat transfer coefficient of the air-sandwich wall is 1.3 and 1.29, respectively. Therefore, the optimal width of the cavity is 20 mm, and the most suitable material is the aerated concrete block.… More >

Xi Wang^*, Guangping Zeng

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.3, pp. 563-576, 2022, DOI:10.32604/fdmp.2022.017884

Abstract An efficient and versatile intelligent algorithm is developed for the control of the cabin environment of wind power generators. The method can be used to monitor and solve wind power generation problems at the same time. It also provides several advantages with respect to other traditional methods which imply significant workload and maintenance personnel. The functional requirements of the intelligent control system are analyzed, and a control algorithm for the stepping motor is selected and evaluated. Through the comparative analysis of the active power and internal temperature curve for three kinds of output power of the prototype, it is proved… More >

Guanni Qu^1,#, Tianai Yue^2,#,*, Xiaoyu Zhang³, Shibiao Wei³

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.3, pp. 591-608, 2022, DOI:10.32604/fdmp.2022.017776

Abstract The present study stems from the realization that the general problem relating to the analysis of wind-induced vibrations in suspension bridges still requires significant attention. Sidewalk railings, overhaul tracks, and deflectors are known to largely affect such dynamics. Here, the influence of a row of water-filled traffic barriers on the response of a sample suspension bridge is investigated numerically. It is shown that the existence of water barriers causes flow separation and non-negligible vortices with respect to the condition with no water barriers. The vortex shedding frequency at the far end is around 41.30 Hz, relatively close to the real… More >

Pengfei Ju^1,2,*, Mingrui Li^3,4, Jingying Wang^3,4

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 449-462, 2022, DOI:10.32604/fdmp.2022.018035

Abstract

Computational fluid dynamics (CFD) has become the main method for the prediction of the properties of the external wind environment in cities and other urban contexts. A review is presented of the existing literature in terms of boundary conditions, building models, computational domains, computational grids, and turbulence models. Some specific issues, such as the accuracy/computational cost ratio and the exploitation of existing empirical correlations, are also examined.

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Tiankui Guo^1,*, Zhilin Luo¹, Shanbo Mou², Ming Chen¹, Yuanzhi Gong³, Jianhua Qin⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 431-447, 2022, DOI:10.32604/fdmp.2022.017861

Abstract Although the dynamics of proppant (small ceramic balls used to prevent opened fractures from closing on the release of pressure) have been the subject of several numerical studies over recent years, large-scale inclined fractures exist in unconventional reservoirs for which relevant information is still missing. In the present study, this problem is investigated numerically considering the influence of several relevant factors such as the fracture roughness, inclination, the proppant particle size, the injection rate and the fluid viscosity. The results show that a rough wall enables the proppant to travel farther and cover larger areas. The inclination angle has little… More >

Xiangxi Du^1,*, Muyun Liu², Yanhua Sun¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 303-312, 2022, DOI:10.32604/fdmp.2022.016242

Abstract The computational fluid dynamics (CFD) technology is analyzed and calculated utilizing the turbulence model and multiphase flow model to explore the performance of internal circulating fluidized beds (ICFB) based on CFD. The three-dimensional simulation method can study the hydrodynamic properties of the ICFB, and the performance of the fluidized bed is optimized. The fluidization performance of the ICFB is improved through the experimental study of the cross-shaped baffle. Then, through the cross-shaped baffle and funnel-shaped baffle placement, the fluidized bed reaches a coupled optimization. The results show that CFD simulation technology can effectively improve the mass transfer efficiency and performance… More >

Zhiyuan Tu¹, Fusheng Peng^1,*, Zijie Wei¹, Guo Qian², Jie Wang¹, Chunjie Huang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1195-1211, 2021, DOI:10.32604/fdmp.2021.011753

Abstract To calculate the flow resistance of a main cable dehumidification system, this study considers the air flow in the main cable as the flow in a porous medium, and adopts the Hagen–Poiseuille equation by using average hydraulic radius and capillary bundle models. A mathematical derivation is combined with an experimental study to obtain a semi-empirical flow resistance formula. Additionally, Fluent software is used to simulate the flow resistance across the main cable relative to the experimental values. Based on the actual measured results for a Yangtze River bridge, this study verifies the semi-empirical formula, and indicates that it can be… More >

Na Xu¹, Shuaizhi Zhou¹, Chunchen Zhang¹, Xiaolei Mou^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.2, pp. 669-685, 2021, DOI:10.32604/cmes.2021.016269

Abstract The dynamic flight stability of hovering insects includes the longitudinal and lateral motion. Research results have shown that for the majority of hovering insects the same longitudinal natural modes are identified and the hovering flight in longitudinal is unstable. However, in lateral, the modal structure for hovering insects could be different and the stability property of lateral disturbance motion is not as robust as that of longitudinal motion. The cranefly possesses larger aspect ratio and lower Reynolds number, and such differences in morphology and kinematics may make the lateral dynamic stability different. In this paper, the lateral flight stability of… More >

W. M. Faizal^1,2, N. N. N. Ghazali^2,*, C. Y. Khor¹, M. Z. Zainon², Irfan Anjum Badruddin^3,4,*, Sarfaraz Kamangar⁴, Norliza Binti Ibrahim⁵, Roziana Mohd Razi⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.2, pp. 583-604, 2021, DOI:10.32604/cmes.2021.015549

Abstract Background: Obstructive sleep apnea is a sleeping disorder that has troubled a sizeable population. There is an active area of research on obstructive sleep apnea that intends to better understand airflow behaviors and therefore treat patients more effectively. This paper aims to investigate the airflow characteristics of the upper airway in an obstructive sleep apnea (OSA) patient under light and heavy breathing conditions by using Turbulent Kinetic Energy (TKE), an accurate method in expressing the flow concentration mechanisms of sleeping disorders. It is important to visualize the concentration of flow in the upper airway in order to identify the severity… More >