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 - 19 July 2024

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 >

Xiaojun Li, Fuyong Su^*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 719-732, 2024, DOI:10.32604/fhmt.2024.051950 - 11 July 2024

Abstract In order to study the effect of oxygen-enriched combustion technology on the temperature field and NO emission in the continuous heating furnace, this paper studies the oxygen-enriched combustion of a pushing steel continuous heating furnace in a domestic company. This study utilizes numerical simulation method, establishes the mathematical models of flow, combustion and NO generation combustion process in the furnace and analyzes the heat transfer process and NO generation in the furnace under different air oxygen content and different wind ratio. The research results show that with the increase of oxygen content in the air, More > Graphic Abstract

Xuehui Jing¹, Junchen Guo¹, Zhiyun Wang^2,*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 919-937, 2024, DOI:10.32604/fhmt.2024.049689 - 11 July 2024

Abstract In this paper, the combustion conditions in the boiler furnace of a 660 MW tangential fired pulverized coal boiler are numerically simulated at 15% and 20% rated loads, to study the flexibility of coal-fired power units on ultra-low load operation. The numerical results show that the boiler can operate safely at 15% and 20% ultra-low loads, and the combustion condition in the furnace is better at 20% load, and the tangent circles formed by each characteristic section in the furnace are better, and when the boiler load is decreased to 15%, the tangent circles in… More >

Ivan Sboev^1,*, Tatyana Lyubimova^2,3, Konstantin Rybkin³, Michael Kuchinskiy^2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1425-1439, 2024, DOI:10.32604/fdmp.2024.051341 - 27 June 2024

Abstract The intensification of physicochemical processes in the sonochemical reactor chamber is widely used in problems of synthesis, extraction and separation. One of the most important mechanisms at play in such processes is the acoustic cavitation due to the non-uniform distribution of acoustic pressure in the chamber. Cavitation has a strong impact on the surface degradation mechanisms. In this work, a numerical calculation of the acoustic pressure distribution inside the reactor chamber was performed using COMSOL Multiphysics. The numerical results have revealed the dependence of the structure of the acoustic pressure field on the boundary conditions More > Graphic Abstract

Alexey Fedyushkin^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1351-1364, 2024, DOI:10.32604/fdmp.2024.050267 - 27 June 2024

Abstract This study is devoted to an analysis of natural convection and the emergence of delamination in an incompressible fluid encapsulated in a closed region heated from the side. Weak, medium and intensive modes of stationary laminar thermal and thermo-concentration convection are considered. It is shown that nonlinear flow features can radically change the flow structure and characteristics of heat and mass transfer. Moreover, the temperature and concentration segregation in the center of the square region display a non-monotonic dependence on the Grashof number (flow intensity). The formation of a nonstationary periodic structure of thermal convection More >

Lijun Mu, Xiaojia Xue, Jie Bai^*, Xiaoyan Li, Xueliang Han

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1365-1379, 2024, DOI:10.32604/fdmp.2024.049013 - 27 June 2024

Abstract Following large-scale volume fracturing in shale oil reservoirs, well shut-in measures are generally employed. Laboratory tests and field trials have underscored the efficacy of fracturing fluid imbibition during the shut-in phase in augmenting shale oil productivity. Unlike conventional reservoirs, shale oil reservoirs exhibit characteristics such as low porosity, low permeability, and rich content of organic matter and clay minerals. Notably, the osmotic pressure effects occurring between high-salinity formation water and low-salinity fracturing fluids are significant. The current understanding of the mobilization patterns of crude oil in micro-pores during the imbibition process remains nebulous, and the… More >

Jiaqiong Wang^1,2, Tao Yang¹, Chen Hu¹, Yu Zhang^3,*, Ling Zhou^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1203-1218, 2024, DOI:10.32604/fdmp.2023.045825 - 27 June 2024

Abstract To investigate the influence of structural parameters on the performances and internal flow characteristics of partial flow pumps at a low specific speed of 10000 rpm, special attention was paid to the first and second stage impeller guide vanes. Moreover, the impeller blade outlet width, impeller inlet diameter, blade inclination angle, and number of blades were considered for orthogonal tests. Accordingly, nine groups of design solutions were formed, and then used as a basis for the execution of numerical simulations (CFD) aimed at obtaining the efficiency values and heads for each design solution group. The 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 - 27 June 2024

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 >

Safwan Al-sayed, Xi Wang, Yijiang Peng^*

CMC-Computers, Materials & Continua, Vol.79, No.3, pp. 4169-4195, 2024, DOI:10.32604/cmc.2024.048916 - 20 June 2024

Abstract The mechanical properties and failure mechanism of lightweight aggregate concrete (LWAC) is a hot topic in the engineering field, and the relationship between its microstructure and macroscopic mechanical properties is also a frontier research topic in the academic field. In this study, the image processing technology is used to establish a micro-structure model of lightweight aggregate concrete. Through the information extraction and processing of the section image of actual light aggregate concrete specimens, the mesostructural model of light aggregate concrete with real aggregate characteristics is established. The numerical simulation of uniaxial tensile test, uniaxial compression… More >

Xiang Kan¹, Yan Li², Tian Li^1,*, Jiye Zhang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 1075-1091, 2024, DOI:10.32604/fdmp.2023.044050 - 07 June 2024

Abstract A pantograph serves as a vital device for the collection of electricity in trains. However, its aerodynamic resistance can limit the train’s running speed. As installing fairings around the pantograph is known to effectively reduce the resistance, in this study, different fairing lengths are considered and the related aerodynamic performances of pantograph are assessed. In particular, this is accomplished through numerical simulations based on the k-ω Shear Stress Transport (SST) two-equation turbulence model. The results indicate that the fairing diminishes the direct impact of high-speed airflow on the pantograph, thereby reducing its aerodynamic resistance. However, it More >