Shaokun Liu¹, Zhiying Gao^1,2,*, Rina Su^1,2, Mengmeng Yan¹, Jianwen Wang^1,2

Energy Engineering, Vol.121, No.8, pp. 2213-2229, 2024, DOI:10.32604/ee.2024.049616

Abstract Although the aerodynamic loading of wind turbine blades under various conditions has been widely studied, the radial distribution of load along the blade under various yaw conditions and with blade flapping phenomena is poorly understood. This study aims to investigate the effects of second-order flapwise vibration on the mean and fluctuation characteristics of the torque and axial thrust of wind turbines under yaw conditions using computational fluid dynamics (CFD). In the CFD model, the blades are segmented radially to comprehensively analyze the distribution patterns of torque, axial load, and tangential load. The following results are… More >

Liqiong Chen¹, Kui Zhao¹, Kai Zhang^1,*, Duo Xv¹, Hongxvan Hu², Guoguang Ma¹, Wenwen Zhan³

Energy Engineering, Vol.121, No.8, pp. 2143-2165, 2024, DOI:10.32604/ee.2024.049362

Abstract The leakage gas from a buried natural gas pipelines has the great potential to cause economic losses and environmental pollution owing to the complexity of the mountainous environment. In this study, computational fluid dynamics (CFD) method was applied to investigate the diffusion law and hazard range of buried natural gas pipeline leakage in mountainous environment. Based on cloud chart, concentration at the monitoring site and hazard range of lower explosion limit (LEL) and upper explosion limit (UEL), the influences of leakage hole direction and shape, soil property, burial depth, obstacle type on the diffusion law… More >

Yasushi Koito^1,*, Akira Fukushima²

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 869-887, 2024, DOI:10.32604/fhmt.2024.050910

Abstract Thermal and fluid-flow characteristics were numerically analyzed for ultra-thin heat pipes. Many studies have been conducted for ultra-thin heat pipes with a centered wick structure, but this study focused on separated wick structures to increase the evaporation/condensation surface areas within the heat pipe and to reduce the concentration of heat flux within the wick structure. A mathematical heat-pipe model was made in the three-dimensional coordinate system, and the model consisted of three regions: a vapor channel, liquid-wick, and container wall regions. The conservation equations for mass, momentum, and energy were solved numerically with boundary conditions… More >

Yongguo Li^1,2, Caiyin Xu^1,2,*, Can Qin^1,2, Dingjian Zheng^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1251-1263, 2024, DOI:10.32604/fdmp.2023.044804

Abstract The so-called ORC (Organic Rankine Cycle) heat recovery technology has attracted much attention with regard to medium and low temperature waste heat recovery. In the present study, it is applied to a Tesla turbine. At the same time, the effects of the disc speed, diameter and inter-disc gap on the internal flow field and output power of the turbine are also investigated by means of CFD (Computational Fluid Dynamics) numerical simulation, by which the pressure, velocity, and output efficiency of the internal flow field are obtained under different internal and external conditions. The highest efficiency More >

Vladimir Ya. Modorskii, Ivan E. Cherepanov^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 1031-1043, 2024, DOI:10.32604/fdmp.2024.048494

Abstract A transition to clean hydrogen energy will not be possible until the issues related to its production, transportation, storage, etc., are adequately resolved. Currently, however, it is possible to use methane-hydrogen mixtures. Natural gas can be transported using a pipeline system with the required pressure being maintained by gas compression stations. This method, however, is affected by some problems too. Compressors emergency stops can be induced by vibrations because in some cases, mechanical methods are not able to reduce the vibration amplitude. As an example, it is known that a gas-dynamic flow effect in labyrinth… More >

Yulin Luo^1,2,#, Panpan Yang^2,#, Mengmeng Bi², Leifeng Xu², Fang Du^3,*, Jun Ming^2,*

Phyton-International Journal of Experimental Botany, Vol.93, No.5, pp. 1057-1066, 2024, DOI:10.32604/phyton.2024.051197

Abstract The xylem undergoes physiological changes in response to various environmental conditions during the process of plant growth. To understand these physiological changes, it is extremely important to observe the transport of xylem. In this study, the distribution and structure of vascular bundle in Lilium lancifolium were observed using the method of semithin section. Methods for introducing a fluorescent tracer into the xylem of the stems were evaluated. Then, the transport rule of 5(6)-Carboxyfluorescein diacetate (CFDA) in the xylem of the stem of L. lancifolium was studied by fluorescence dye in live cells tracer technology. The results showed… More >

Fei Wang, Qinpeng Meng, Jinchi Zhao, Xin Wang, Yuhong Liu, Qianru Zhang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 829-846, 2024, DOI:10.32604/fdmp.2023.026917

Abstract Buildings with large open spaces in which chemicals are handled are often exposed to the risk of explosions. Computational fluid dynamics is a useful and convenient way to investigate contaminant dispersion in such large spaces. The turbulent Schmidt number (Sc_t) concept has typically been used in this regard, and most studies have adopted a default value. We studied the concentration distribution for sulfur hexafluoride (SF₆) assuming different emission rates and considering the effect of Sc_t. Then we examined the same problem for a light gas by assuming hydrogen gas (H₂) as the contaminant. When SF₆ was considered as More >

D. S. Martínez^†, J. P. Solano, J. Pérez, A. Viedma

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-10, 2011, DOI:10.5098/hmt.v2.3.3002

Abstract Non-Newtonian flow and heat transfer in tubes of heat exchangers with reciprocating insert devices have been numerically investigated. The heat exchanger is mechanically assisted by a reciprocating cylinder, which moves the scraping rods inserted in the tubes. An array of semi-circular elements is mounted on each rod, with a pitch p=5D. These elements fit the internal diameter of the tubes. During the reciprocating motion, they scrape the inner tube wall, avoiding fouling. Additionally, the movement of the inserted device generates macroscopic displacements of the flow, which continuously mix core regions with peripheral flow. A power More >

Rajesh Kumar Panda, B.V.S.S.S. Prasad^*

Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-10, 2011, DOI:10.5098/hmt.v2.1.3008

Abstract Conjugate heat transfer from a flat circular disk is investigated both computationally and experimentally with a constant heat flux imposed on its bottom surface and a shower head of air jets impinging on the top surface. The shower head consists of a central jet surrounded by four neighboring perimeter jets. Measured temperature data at twelve locations within the plate are compared with the conjugate heat transfer result obtained at the same locations computationally by Shear Stress Transport (SST) κ-ω turbulence model. The spacing to orifice diameter ratio (H/d = 1 to 4), the jet Reynolds… More >

Jun Xu¹, Kai Bi¹, Yibin Lu^2,*, Tiantian Wang^2,3, Hang Zhang², Zeyuan Zheng³, Fushan Shi³, Yaxin Zheng³, Xiaoying Li², Jingping Yang³

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2727-2748, 2024, DOI:10.32604/cmes.2023.031341

Abstract The spread and removal of pollution sources, namely, cough-released droplets in three different areas (front, middle, and rear areas) of a fully-loaded passenger car in a high-speed train under different fresh air flow volume were studied using computational fluid dynamics (CFD) method. In addition, the structure of indoor flow fields was also analysed. The results show that the large eddies are more stable and flow faster in the air supply under Mode 2 (fresh air volume: 2200 m³/h) compared to Mode 1 (fresh air volume: 1100 m³/h). By analysing the spreading process of droplets sprayed at different locations… More >