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. 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 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 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,… 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… More >

Neil Stephen Lopez^1,*, Selena Kay Galeos¹, Brian Raphael Calderon¹, David Roy Dominguez¹, Bryan Joseph Uy¹, Rupesh Iyengar²

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 333-347, 2021, DOI:10.32604/fdmp.2021.011213

Abstract The underfloor air distribution (UFAD) system has not been able to penetrate the residential and commercial air conditioning industry significantly until now. To date, the most notable applications are found in datacenters because of their more demanding thermal stratification and cooling requirements. In addition to highlighting the advantages of the UFAD system over the traditional overhead (OH) system, this study compares various ventilation layouts for a UFAD system. Four different UFAD ventilation layouts are compared and one OH layout. The results show that using multiple swirl-type diffusers creates a more uniform floor-to-knee temperature and less More >

Makoto Yamamoto^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 19-19, 2021, DOI:10.32604/icces.2021.08478

Abstract In a turbine of a jet engine, deposition phenomenon is often observed. Deposition is a phenomenon that particles such as volcanic ash, sand and dust passing through a combustion chamber of a jet engine are melt, rapidly cooled and then accumulate on the turbine blade and end-wall surfaces. Deposition is one of critical problems when aircraft flies in a cloud with many particles. Obviously, deposition can degrade the aerodynamic performance of the turbine blade and vane, and make partial or complete blockage of film-cooling holes. As the result, deposition deteriorates safety and life time of… More >

Suvash C. Saha^1,*, Ali M. Sefidan², Atta Sojoudi³, Mohammad M. Molla⁴

Energy Engineering, Vol.118, No.3, pp. 487-506, 2021, DOI:10.32604/EE.2021.014088

Abstract One primordial consideration in residential ventilation standards is the comfort of provided to people living in those habitations. This is highly dependent on the thermal and fluid flow conditions, the space geometry and so on. Efficient designs may reduce the energy usage, making the buildings more sustainable over a longer period of time. This study aims to investigate the impact of whole day thermal conditions on the fluid flow structure and heat transfer phenomena, mainly natural convection, inside a partitioned attic-shaped configuration. The Finite Volume Method is applied to solve the governing equations. Sinusoidal thermal… More >

Yunduo Charles Zhao^1,2,#, Parham Vatankhah^1,#, Tiffany Goh^1,2,3, Jiaqiu Wang⁴, Xuanyi Valeria Chen¹, Moein Navvab Kashani^5,6, Keke Zheng⁷, Zhiyong Li⁴, Lining Arnold Ju^1,2,3,*

Molecular & Cellular Biomechanics, Vol.18, No.1, pp. 1-10, 2021, DOI:10.32604/mcb.2021.012598

Abstract Platelet aggregation plays a central role in pathological thrombosis, preventing healthy physiological blood flow within the circulatory system. For decades, it was believed that platelet aggregation was primarily driven by soluble agonists such as thrombin, adenosine diphosphate and thromboxane A2. However, recent experimental findings have unveiled an intriguing but complementary biomechanical mechanism—the shear rate gradients generated from flow disturbance occurring at sites of blood vessel narrowing, otherwise known as stenosis, may rapidly trigger platelet recruitment and subsequent aggregation. In our Nature Materials 2019 paper [1], we employed microfluidic devices which incorporated micro-scale stenoses to elucidate the… More >